- propagate 'No space left on device' error in fixdep to Make
- allow Clang to use its integrated assembler
- improve some coccinelle scripts
- add a new flag KBUILD_ABS_SRCTREE to request Kbuild to use absolute
path for $(srctree).
- do not ignore errors when compression utility is missing
- misc cleanups
* tag 'kbuild-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (49 commits)
kbuild: use -- separater intead of $(filter-out ...) for cc-cross-prefix
kbuild: Inform user to pass ARCH= for make mrproper
kbuild: fix compression errors getting ignored
kbuild: add a flag to force absolute path for srctree
kbuild: replace KBUILD_SRCTREE with boolean building_out_of_srctree
kbuild: remove src and obj from the top Makefile
scripts/tags.sh: remove unused environment variables from comments
scripts/tags.sh: drop SUBARCH support for ARM
kbuild: compile-test kernel headers to ensure they are self-contained
kheaders: include only headers into kheaders_data.tar.xz
kheaders: remove meaningless -R option of 'ls'
kbuild: support header-test-pattern-y
kbuild: do not create wrappers for header-test-y
kbuild: compile-test exported headers to ensure they are self-contained
init/Kconfig: add CONFIG_CC_CAN_LINK
kallsyms: exclude kasan local symbols on s390
kbuild: add more hints about SUBDIRS replacement
coccinelle: api/stream_open: treat all wait_.*() calls as blocking
coccinelle: put_device: Add a cast to an expression for an assignment
coccinelle: put_device: Adjust a message construction
...
Merge tag 'asm-generic-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic updates from Arnd Bergmann:
"The asm-generic changes for 5.3 consist of a cleanup series to remove
ptrace.h from Christoph Hellwig, who explains:
'asm-generic/ptrace.h is a little weird in that it doesn't actually
implement any functionality, but it provided multiple layers of
macros that just implement trivial inline functions. We implement
those directly in the few architectures and be off with a much
simpler design.'
at https://lore.kernel.org/lkml/20190624054728.30966-1-hch@lst.de/"
* tag 'asm-generic-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
asm-generic: remove ptrace.h
x86: don't use asm-generic/ptrace.h
sh: don't use asm-generic/ptrace.h
powerpc: don't use asm-generic/ptrace.h
arm64: don't use asm-generic/ptrace.h
- Add CPU measurement counters for newer machines.
- Add base DASD thin provisioning support and code cleanups.
* tag 's390-5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (21 commits)
s390/unwind: avoid int overflow in outside_of_stack
s390/zcrypt: remove the exporting of ap_query_configuration
s390/pci: add mio_enabled attribute
s390: fix setting of mio addressing control
s390/ipl: Fix detection of has_secure attribute
s390: vfio-ap: fix irq registration
s390/cpumf: Add extended counter set definitions for model 8561 and 8562
s390/dasd: Handle out-of-space constraint
s390/dasd: Add discard support for ESE volumes
s390/dasd: Use ALIGN_DOWN macro
s390/dasd: Make dasd_setup_queue() a discipline function
s390/dasd: Add new ioctl to release space
s390/dasd: Add dasd_sleep_on_queue_interruptible()
s390/dasd: Add missing intensity definition
s390/dasd: Fix whitespace
s390/dasd: Add dynamic formatting support for ESE volumes
s390/dasd: Recognise data for ESE volumes
s390/dasd: Put sub-order definitions in a separate section
s390/dasd: Make layout analysis ESE compatible
s390/dasd: Remove old defines and function
...
Merge tag 'nios2-v5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2
Pull arch/nios2 updates from Ley Foon Tan.
* tag 'nios2-v5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
nios2: configs: Remove useless UEVENT_HELPER_PATH
nios2: remove pointless second entry for CONFIG_TRACE_IRQFLAGS_SUPPORT
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"ARM:
- support for chained PMU counters in guests
- improved SError handling
- handle Neoverse N1 erratum #1349291
- allow side-channel mitigation status to be migrated
- standardise most AArch64 system register accesses to msr_s/mrs_s
- fix host MPIDR corruption on 32bit
- selftests ckleanups
x86:
- PMU event {white,black}listing
- ability for the guest to disable host-side interrupt polling
- fixes for enlightened VMCS (Hyper-V pv nested virtualization),
- new hypercall to yield to IPI target
- support for passing cstate MSRs through to the guest
- lots of cleanups and optimizations
Generic:
- Some txt->rST conversions for the documentation"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (128 commits)
Documentation: virtual: Add toctree hooks
Documentation: kvm: Convert cpuid.txt to .rst
Documentation: virtual: Convert paravirt_ops.txt to .rst
KVM: x86: Unconditionally enable irqs in guest context
KVM: x86: PMU Event Filter
kvm: x86: Fix -Wmissing-prototypes warnings
KVM: Properly check if "page" is valid in kvm_vcpu_unmap
KVM: arm/arm64: Initialise host's MPIDRs by reading the actual register
KVM: LAPIC: Retry tune per-vCPU timer_advance_ns if adaptive tuning goes insane
kvm: LAPIC: write down valid APIC registers
KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s
KVM: doc: Add API documentation on the KVM_REG_ARM_WORKAROUNDS register
KVM: arm/arm64: Add save/restore support for firmware workaround state
arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests
KVM: arm/arm64: Support chained PMU counters
KVM: arm/arm64: Remove pmc->bitmask
KVM: arm/arm64: Re-create event when setting counter value
KVM: arm/arm64: Extract duplicated code to own function
KVM: arm/arm64: Rename kvm_pmu_{enable/disable}_counter functions
KVM: LAPIC: ARBPRI is a reserved register for x2APIC
...
Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyper-v updates from Sasha Levin:
- Add a module description to the Hyper-V vmbus module.
- Rework some vmbus code to separate architecture specifics out to
arch/x86/. This is part of the work of adding arm64 support to
Hyper-V.
* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
Drivers: hv: vmbus: Break out ISA independent parts of mshyperv.h
drivers: hv: Add a module description line to the hv_vmbus driver
Merge tag 'dma-mapping-5.3' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:
- move the USB special case that bounced DMA through a device bar into
the USB code instead of handling it in the common DMA code (Laurentiu
Tudor and Fredrik Noring)
- don't dip into the global CMA pool for single page allocations
(Nicolin Chen)
- fix a crash when allocating memory for the atomic pool failed during
boot (Florian Fainelli)
- move support for MIPS-style uncached segments to the common code and
use that for MIPS and nios2 (me)
- make support for DMA_ATTR_NON_CONSISTENT and
DMA_ATTR_NO_KERNEL_MAPPING generic (me)
- convert nds32 to the generic remapping allocator (me)
* tag 'dma-mapping-5.3' of git://git.infradead.org/users/hch/dma-mapping: (29 commits)
dma-mapping: mark dma_alloc_need_uncached as __always_inline
MIPS: only select ARCH_HAS_UNCACHED_SEGMENT for non-coherent platforms
usb: host: Fix excessive alignment restriction for local memory allocations
lib/genalloc.c: Add algorithm, align and zeroed family of DMA allocators
nios2: use the generic uncached segment support in dma-direct
nds32: use the generic remapping allocator for coherent DMA allocations
arc: use the generic remapping allocator for coherent DMA allocations
dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code
dma-direct: handle DMA_ATTR_NON_CONSISTENT in common code
dma-mapping: add a dma_alloc_need_uncached helper
openrisc: remove the partial DMA_ATTR_NON_CONSISTENT support
arc: remove the partial DMA_ATTR_NON_CONSISTENT support
arm-nommu: remove the partial DMA_ATTR_NON_CONSISTENT support
ARM: dma-mapping: allow larger DMA mask than supported
dma-mapping: truncate dma masks to what dma_addr_t can hold
iommu/dma: Apply dma_{alloc,free}_contiguous functions
dma-remap: Avoid de-referencing NULL atomic_pool
MIPS: use the generic uncached segment support in dma-direct
dma-direct: provide generic support for uncached kernel segments
au1100fb: fix DMA API abuse
...
coresight: Make the coresight_device_fwnode_match declaration's fwnode parameter const
Fix Linus' merge error in the parent commit, causing:
drivers/hwtracing/coresight/coresight.c:1051:11: error: incompatible pointer types passing 'int (struct device *, void *)' to parameter of type 'int (*)(struct device *, const void *)' [-Werror,-Wincompatible-pointer-types]
coresight_device_fwnode_match);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/device.h:173:17: note: passing argument to parameter 'match' here
int (*match)(struct device *dev, const void *data));
^
due to missed header file fixup.
Fixes: f632a8170a6b ("Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core") Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
[ Greg even sent this patch with his pull request, but I stupidly
thought it was the merge resolution fix I had already done as part of
the merge. But no, this was the extra fix for the header file
that goes with the definition I _had_ caught - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core and debugfs updates from Greg KH:
"Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse easier
due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of
merge issues that Stephen has been patient with me for"
* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
debugfs: make error message a bit more verbose
orangefs: fix build warning from debugfs cleanup patch
ubifs: fix build warning after debugfs cleanup patch
driver: core: Allow subsystems to continue deferring probe
drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
arch_topology: Remove error messages on out-of-memory conditions
lib: notifier-error-inject: no need to check return value of debugfs_create functions
swiotlb: no need to check return value of debugfs_create functions
ceph: no need to check return value of debugfs_create functions
sunrpc: no need to check return value of debugfs_create functions
ubifs: no need to check return value of debugfs_create functions
orangefs: no need to check return value of debugfs_create functions
nfsd: no need to check return value of debugfs_create functions
lib: 842: no need to check return value of debugfs_create functions
debugfs: provide pr_fmt() macro
debugfs: log errors when something goes wrong
drivers: s390/cio: Fix compilation warning about const qualifiers
drivers: Add generic helper to match by of_node
driver_find_device: Unify the match function with class_find_device()
bus_find_device: Unify the match callback with class_find_device
...
Merge updates from Andrew Morton:
"Am experimenting with splitting MM up into identifiable subsystems
perhaps with a view to gitifying it in complex ways. Also with more
verbose "incoming" emails.
hotfixes:
mm: vmscan: scan anonymous pages on file refaults
mm/nvdimm: add is_ioremap_addr and use that to check ioremap address
mm/memcontrol: fix wrong statistics in memory.stat
mm/z3fold.c: lock z3fold page before __SetPageMovable()
nilfs2: do not use unexported cpu_to_le32()/le32_to_cpu() in uapi header
MAINTAINERS: nilfs2: update email address
iommu:
include/linux/dmar.h: replace single-char identifiers in macros
scripts:
scripts/decode_stacktrace: match basepath using shell prefix operator, not regex
scripts/decode_stacktrace: look for modules with .ko.debug extension
scripts/spelling.txt: drop "sepc" from the misspelling list
scripts/spelling.txt: add spelling fix for prohibited
scripts/decode_stacktrace: Accept dash/underscore in modules
scripts/spelling.txt: add more spellings to spelling.txt
arch/sh:
arch/sh/configs/sdk7786_defconfig: remove CONFIG_LOGFS
sh: config: remove left-over BACKLIGHT_LCD_SUPPORT
sh: prevent warnings when using iounmap
ocfs2:
fs: ocfs: fix spelling mistake "hearbeating" -> "heartbeat"
ocfs2/dlm: use struct_size() helper
ocfs2: add last unlock times in locking_state
ocfs2: add locking filter debugfs file
ocfs2: add first lock wait time in locking_state
ocfs: no need to check return value of debugfs_create functions
fs/ocfs2/dlmglue.c: unneeded variable: "status"
ocfs2: use kmemdup rather than duplicating its implementation
mm:slab-generic:
Patch series "mm/slab: Improved sanity checking":
mm/slab: validate cache membership under freelist hardening
mm/slab: sanity-check page type when looking up cache
lkdtm/heap: add tests for freelist hardening
mm:slub:
mm/slub.c: avoid double string traverse in kmem_cache_flags()
slub: don't panic for memcg kmem cache creation failure
mm:kmemleak:
mm/kmemleak.c: fix check for softirq context
mm/kmemleak.c: change error at _write when kmemleak is disabled
docs: kmemleak: add more documentation details
mm:kasan:
mm/kasan: print frame description for stack bugs
Patch series "Bitops instrumentation for KASAN", v5:
lib/test_kasan: add bitops tests
x86: use static_cpu_has in uaccess region to avoid instrumentation
asm-generic, x86: add bitops instrumentation for KASAN
Patch series "mm/kasan: Add object validation in ksize()", v3:
mm/kasan: introduce __kasan_check_{read,write}
mm/kasan: change kasan_check_{read,write} to return boolean
lib/test_kasan: Add test for double-kzfree detection
mm/slab: refactor common ksize KASAN logic into slab_common.c
mm/kasan: add object validation in ksize()
mm:cleanups:
include/linux/pfn_t.h: remove pfn_t_to_virt()
Patch series "remove ARCH_SELECT_MEMORY_MODEL where it has no effect":
arm: remove ARCH_SELECT_MEMORY_MODEL
s390: remove ARCH_SELECT_MEMORY_MODEL
sparc: remove ARCH_SELECT_MEMORY_MODEL
mm/gup.c: make follow_page_mask() static
mm/memory.c: trivial clean up in insert_page()
mm: make !CONFIG_HUGE_PAGE wrappers into static inlines
include/linux/mm_types.h: ifdef struct vm_area_struct::swap_readahead_info
mm: remove the account_page_dirtied export
mm/page_isolation.c: change the prototype of undo_isolate_page_range()
include/linux/vmpressure.h: use spinlock_t instead of struct spinlock
mm: remove the exporting of totalram_pages
include/linux/pagemap.h: document trylock_page() return value
mm:debug:
mm/failslab.c: by default, do not fail allocations with direct reclaim only
Patch series "debug_pagealloc improvements":
mm, debug_pagelloc: use static keys to enable debugging
mm, page_alloc: more extensive free page checking with debug_pagealloc
mm, debug_pagealloc: use a page type instead of page_ext flag
mm:pagecache:
Patch series "fix filler_t callback type mismatches", v2:
mm/filemap.c: fix an overly long line in read_cache_page
mm/filemap: don't cast ->readpage to filler_t for do_read_cache_page
jffs2: pass the correct prototype to read_cache_page
9p: pass the correct prototype to read_cache_page
mm/filemap.c: correct the comment about VM_FAULT_RETRY
mm:swap:
mm, swap: fix race between swapoff and some swap operations
mm/swap_state.c: simplify total_swapcache_pages() with get_swap_device()
mm, swap: use rbtree for swap_extent
mm/mincore.c: fix race between swapoff and mincore
mm:memcg:
memcg, oom: no oom-kill for __GFP_RETRY_MAYFAIL
memcg, fsnotify: no oom-kill for remote memcg charging
mm, memcg: introduce memory.events.local
mm: memcontrol: dump memory.stat during cgroup OOM
Patch series "mm: reparent slab memory on cgroup removal", v7:
mm: memcg/slab: postpone kmem_cache memcg pointer initialization to memcg_link_cache()
mm: memcg/slab: rename slab delayed deactivation functions and fields
mm: memcg/slab: generalize postponed non-root kmem_cache deactivation
mm: memcg/slab: introduce __memcg_kmem_uncharge_memcg()
mm: memcg/slab: unify SLAB and SLUB page accounting
mm: memcg/slab: don't check the dying flag on kmem_cache creation
mm: memcg/slab: synchronize access to kmem_cache dying flag using a spinlock
mm: memcg/slab: rework non-root kmem_cache lifecycle management
mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages
mm: memcg/slab: reparent memcg kmem_caches on cgroup removal
mm, memcg: add a memcg_slabinfo debugfs file
mm:gup:
Patch series "switch the remaining architectures to use generic GUP", v4:
mm: use untagged_addr() for get_user_pages_fast addresses
mm: simplify gup_fast_permitted
mm: lift the x86_32 PAE version of gup_get_pte to common code
MIPS: use the generic get_user_pages_fast code
sh: add the missing pud_page definition
sh: use the generic get_user_pages_fast code
sparc64: add the missing pgd_page definition
sparc64: define untagged_addr()
sparc64: use the generic get_user_pages_fast code
mm: rename CONFIG_HAVE_GENERIC_GUP to CONFIG_HAVE_FAST_GUP
mm: reorder code blocks in gup.c
mm: consolidate the get_user_pages* implementations
mm: validate get_user_pages_fast flags
mm: move the powerpc hugepd code to mm/gup.c
mm: switch gup_hugepte to use try_get_compound_head
mm: mark the page referenced in gup_hugepte
mm/gup: speed up check_and_migrate_cma_pages() on huge page
mm/gup.c: remove some BUG_ONs from get_gate_page()
mm/gup.c: mark undo_dev_pagemap as __maybe_unused
mm:pagemap:
asm-generic, x86: introduce generic pte_{alloc,free}_one[_kernel]
alpha: switch to generic version of pte allocation
arm: switch to generic version of pte allocation
arm64: switch to generic version of pte allocation
csky: switch to generic version of pte allocation
m68k: sun3: switch to generic version of pte allocation
mips: switch to generic version of pte allocation
nds32: switch to generic version of pte allocation
nios2: switch to generic version of pte allocation
parisc: switch to generic version of pte allocation
riscv: switch to generic version of pte allocation
um: switch to generic version of pte allocation
unicore32: switch to generic version of pte allocation
mm/pgtable: drop pgtable_t variable from pte_fn_t functions
mm/memory.c: fail when offset == num in first check of __vm_map_pages()
mm:infrastructure:
mm/mmu_notifier: use hlist_add_head_rcu()
mm:vmalloc:
Patch series "Some cleanups for the KVA/vmalloc", v5:
mm/vmalloc.c: remove "node" argument
mm/vmalloc.c: preload a CPU with one object for split purpose
mm/vmalloc.c: get rid of one single unlink_va() when merge
mm/vmalloc.c: switch to WARN_ON() and move it under unlink_va()
mm/vmalloc.c: spelling> s/informaion/information/
mm:initialization:
mm/large system hash: use vmalloc for size > MAX_ORDER when !hashdist
mm/large system hash: clear hashdist when only one node with memory is booted
mm:pagealloc:
arm64: move jump_label_init() before parse_early_param()
Patch series "add init_on_alloc/init_on_free boot options", v10:
mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options
mm: init: report memory auto-initialization features at boot time
mm:vmscan:
mm: vmscan: remove double slab pressure by inc'ing sc->nr_scanned
mm: vmscan: correct some vmscan counters for THP swapout
mm:tools:
tools/vm/slabinfo: order command line options
tools/vm/slabinfo: add partial slab listing to -X
tools/vm/slabinfo: add option to sort by partial slabs
tools/vm/slabinfo: add sorting info to help menu
mm:proc:
proc: use down_read_killable mmap_sem for /proc/pid/maps
proc: use down_read_killable mmap_sem for /proc/pid/smaps_rollup
proc: use down_read_killable mmap_sem for /proc/pid/pagemap
proc: use down_read_killable mmap_sem for /proc/pid/clear_refs
proc: use down_read_killable mmap_sem for /proc/pid/map_files
mm: use down_read_killable for locking mmap_sem in access_remote_vm
mm: smaps: split PSS into components
mm: vmalloc: show number of vmalloc pages in /proc/meminfo
mm:oom-kill:
mm: memcontrol: use CSS_TASK_ITER_PROCS at mem_cgroup_scan_tasks()
mm, oom: refactor dump_tasks for memcg OOMs
mm, oom: remove redundant task_in_mem_cgroup() check
oom: decouple mems_allowed from oom_unkillable_task
mm/oom_kill.c: remove redundant OOM score normalization in select_bad_process()"
* akpm: (147 commits)
mm/oom_kill.c: remove redundant OOM score normalization in select_bad_process()
oom: decouple mems_allowed from oom_unkillable_task
mm, oom: remove redundant task_in_mem_cgroup() check
mm, oom: refactor dump_tasks for memcg OOMs
mm: memcontrol: use CSS_TASK_ITER_PROCS at mem_cgroup_scan_tasks()
mm/memory-failure.c: clarify error message
mm: vmalloc: show number of vmalloc pages in /proc/meminfo
mm: smaps: split PSS into components
mm: use down_read_killable for locking mmap_sem in access_remote_vm
proc: use down_read_killable mmap_sem for /proc/pid/map_files
proc: use down_read_killable mmap_sem for /proc/pid/clear_refs
proc: use down_read_killable mmap_sem for /proc/pid/pagemap
proc: use down_read_killable mmap_sem for /proc/pid/smaps_rollup
proc: use down_read_killable mmap_sem for /proc/pid/maps
tools/vm/slabinfo: add sorting info to help menu
tools/vm/slabinfo: add option to sort by partial slabs
tools/vm/slabinfo: add partial slab listing to -X
tools/vm/slabinfo: order command line options
mm: vmscan: correct some vmscan counters for THP swapout
mm: vmscan: remove double slab pressure by inc'ing sc->nr_scanned
...
oom: decouple mems_allowed from oom_unkillable_task
Commit ef08e3b4981a ("[PATCH] cpusets: confine oom_killer to
mem_exclusive cpuset") introduces a heuristic where a potential
oom-killer victim is skipped if the intersection of the potential victim
and the current (the process triggered the oom) is empty based on the
reason that killing such victim most probably will not help the current
allocating process.
However the commit 7887a3da753e ("[PATCH] oom: cpuset hint") changed the
heuristic to just decrease the oom_badness scores of such potential
victim based on the reason that the cpuset of such processes might have
changed and previously they may have allocated memory on mems where the
current allocating process can allocate from.
Unintentionally 7887a3da753e ("[PATCH] oom: cpuset hint") introduced a
side effect as the oom_badness is also exposed to the user space through
/proc/[pid]/oom_score, so, readers with different cpusets can read
different oom_score of the same process.
Later, commit 6cf86ac6f36b ("oom: filter tasks not sharing the same
cpuset") fixed the side effect introduced by 7887a3da753e by moving the
cpuset intersection back to only oom-killer context and out of
oom_badness. However the combination of ab290adbaf8f ("oom: make
oom_unkillable_task() helper function") and 26ebc984913b ("oom:
/proc/<pid>/oom_score treat kernel thread honestly") unintentionally
brought back the cpuset intersection check into the oom_badness
calculation function.
Other than doing cpuset/mempolicy intersection from oom_badness, the memcg
oom context is also doing cpuset/mempolicy intersection which is quite
wrong and is caught by syzcaller with the following report:
The fix is to decouple the cpuset/mempolicy intersection check from
oom_unkillable_task() and make sure cpuset/mempolicy intersection check is
only done in the global oom context.
[shakeelb@google.com: change function name and update comment] Link: http://lkml.kernel.org/r/20190628152421.198994-3-shakeelb@google.com Link: http://lkml.kernel.org/r/20190624212631.87212-3-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Reported-by: syzbot+d0fc9d3c166bc5e4a94b@syzkaller.appspotmail.com Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Paul Jackson <pj@sgi.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm, oom: remove redundant task_in_mem_cgroup() check
oom_unkillable_task() can be called from three different contexts i.e.
global OOM, memcg OOM and oom_score procfs interface. At the moment
oom_unkillable_task() does a task_in_mem_cgroup() check on the given
process. Since there is no reason to perform task_in_mem_cgroup()
check for global OOM and oom_score procfs interface, those contexts
provide NULL memcg and skips the task_in_mem_cgroup() check. However
for memcg OOM context, the oom_unkillable_task() is always called from
mem_cgroup_scan_tasks() and thus task_in_mem_cgroup() check becomes
redundant and effectively dead code. So, just remove the
task_in_mem_cgroup() check altogether.
Link: http://lkml.kernel.org/r/20190624212631.87212-2-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Paul Jackson <pj@sgi.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dump_tasks() traverses all the existing processes even for the memcg OOM
context which is not only unnecessary but also wasteful. This imposes a
long RCU critical section even from a contained context which can be quite
disruptive.
Change dump_tasks() to be aligned with select_bad_process and use
mem_cgroup_scan_tasks to selectively traverse only processes of the target
memcg hierarchy during memcg OOM.
Link: http://lkml.kernel.org/r/20190617231207.160865-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Paul Jackson <pj@sgi.com> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: memcontrol: use CSS_TASK_ITER_PROCS at mem_cgroup_scan_tasks()
Since commit c03cd7738a83 ("cgroup: Include dying leaders with live
threads in PROCS iterations") corrected how CSS_TASK_ITER_PROCS works,
mem_cgroup_scan_tasks() can use CSS_TASK_ITER_PROCS in order to check
only one thread from each thread group.
Roman Gushchin [Fri, 12 Jul 2019 04:00:13 +0000 (21:00 -0700)]
mm: vmalloc: show number of vmalloc pages in /proc/meminfo
Vmalloc() is getting more and more used these days (kernel stacks, bpf and
percpu allocator are new top users), and the total % of memory consumed by
vmalloc() can be pretty significant and changes dynamically.
/proc/meminfo is the best place to display this information: its top goal
is to show top consumers of the memory.
Since the VmallocUsed field in /proc/meminfo is not in use for quite a
long time (it has been defined to 0 by a5ad88ce8c7f ("mm: get rid of
'vmalloc_info' from /proc/meminfo")), let's reuse it for showing the
actual physical memory consumption of vmalloc().
Link: http://lkml.kernel.org/r/20190417194002.12369-3-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Luigi Semenzato [Fri, 12 Jul 2019 04:00:10 +0000 (21:00 -0700)]
mm: smaps: split PSS into components
Report separate components (anon, file, and shmem) for PSS in
smaps_rollup.
This helps understand and tune the memory manager behavior in consumer
devices, particularly mobile devices. Many of them (e.g. chromebooks and
Android-based devices) use zram for anon memory, and perform disk reads
for discarded file pages. The difference in latency is large (e.g.
reading a single page from SSD is 30 times slower than decompressing a
zram page on one popular device), thus it is useful to know how much of
the PSS is anon vs. file.
All the information is already present in /proc/pid/smaps, but much more
expensive to obtain because of the large size of that procfs entry.
This patch also removes a small code duplication in smaps_account, which
would have gotten worse otherwise.
Also updated Documentation/filesystems/proc.txt (the smaps section was a
bit stale, and I added a smaps_rollup section) and
Documentation/ABI/testing/procfs-smaps_rollup.
mm: use down_read_killable for locking mmap_sem in access_remote_vm
This function is used by ptrace and proc files like /proc/pid/cmdline and
/proc/pid/environ.
Access_remote_vm never returns error codes, all errors are ignored and
only size of successfully read data is returned. So, if current task was
killed we'll simply return 0 (bytes read).
Mmap_sem could be locked for a long time or forever if something goes
wrong. Using a killable lock permits cleanup of stuck tasks and
simplifies investigation.
Link: http://lkml.kernel.org/r/156007494202.3335.16782303099589302087.stgit@buzz Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Michal Koutný <mkoutny@suse.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tools/vm/slabinfo: add option to sort by partial slabs
We would like to get a better view of the level of fragmentation within
the SLUB allocator. Total number of partial slabs is an indicator of
fragmentation.
Add a command line option (-P | --partial) to sort the slab list by total
number of partial slabs.
Link: http://lkml.kernel.org/r/20190426022622.4089-4-tobin@kernel.org Signed-off-by: Tobin C. Harding <tobin@kernel.org> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com>, Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@iki.fi> Cc: Qian Cai <cai@lca.pw> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During recent discussion on LKML over SLAB vs SLUB it was suggested by
Jesper that it would be nice to have a tool to view the current
fragmentation of the slab allocators. CC list for this set is taken
from that thread.
For SLUB we have all the information for this already exposed by the
kernel and also we have a userspace tool for displaying this info:
tools/vm/slabinfo.c
Extend slabinfo to improve the fragmentation information by enabling
sorting of caches by number of partial slabs.
Also add cache list sorted in this manner to the output of `slabinfo -X`.
This patch (of 4):
get_opt() has a spurious character within the option string. Remove it
and reorder the options in alphabetic order so that it is easier to keep
the options correct. Use the same ordering for command help output and
long option handling code.
Link: http://lkml.kernel.org/r/20190426022622.4089-2-tobin@kernel.org Signed-off-by: Tobin C. Harding <tobin@kernel.org> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Pekka Enberg <penberg@iki.fi> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Tejun Heo <tj@kernel.org> Cc: Qian Cai <cai@lca.pw> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Alexander Duyck <alexander.duyck@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com>, Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yang Shi [Fri, 12 Jul 2019 03:59:30 +0000 (20:59 -0700)]
mm: vmscan: correct some vmscan counters for THP swapout
Commit bd4c82c22c36 ("mm, THP, swap: delay splitting THP after swapped
out"), THP can be swapped out in a whole. But, nr_reclaimed and some
other vm counters still get inc'ed by one even though a whole THP (512
pages) gets swapped out.
This doesn't make too much sense to memory reclaim.
For example, direct reclaim may just need reclaim SWAP_CLUSTER_MAX
pages, reclaiming one THP could fulfill it. But, if nr_reclaimed is not
increased correctly, direct reclaim may just waste time to reclaim more
pages, SWAP_CLUSTER_MAX * 512 pages in worst case.
And, it may cause pgsteal_{kswapd|direct} is greater than
pgscan_{kswapd|direct}, like the below:
nr_reclaimed and nr_scanned must be fixed in parallel otherwise it would
break some page reclaim logic, e.g.
vmpressure: this looks at the scanned/reclaimed ratio so it won't change
semantics as long as scanned & reclaimed are fixed in parallel.
compaction/reclaim: compaction wants a certain number of physical pages
freed up before going back to compacting.
kswapd priority raising: kswapd raises priority if we scan fewer pages
than the reclaim target (which itself is obviously expressed in order-0
pages). As a result, kswapd can falsely raise its aggressiveness even
when it's making great progress.
Other than nr_scanned and nr_reclaimed, some other counters, e.g.
pgactivate, nr_skipped, nr_ref_keep and nr_unmap_fail need to be fixed too
since they are user visible via cgroup, /proc/vmstat or trace points,
otherwise they would be underreported.
When isolating pages from LRUs, nr_taken has been accounted in base page,
but nr_scanned and nr_skipped are still accounted in THP. It doesn't make
too much sense too since this may cause trace point underreport the
numbers as well.
So accounting those counters in base page instead of accounting THP as one
page.
nr_dirty, nr_unqueued_dirty, nr_congested and nr_writeback are used by
file cache, so they are not impacted by THP swap.
This change may result in lower steal/scan ratio in some cases since THP
may get split during page reclaim, then a part of tail pages get reclaimed
instead of the whole 512 pages, but nr_scanned is accounted by 512,
particularly for direct reclaim. But, this should be not a significant
issue.
Link: http://lkml.kernel.org/r/1559025859-72759-2-git-send-email-yang.shi@linux.alibaba.com Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yang Shi [Fri, 12 Jul 2019 03:59:27 +0000 (20:59 -0700)]
mm: vmscan: remove double slab pressure by inc'ing sc->nr_scanned
Commit 9092c71bb724 ("mm: use sc->priority for slab shrink targets") has
broken up the relationship between sc->nr_scanned and slab pressure.
The sc->nr_scanned can't double slab pressure anymore. So, it sounds no
sense to still keep sc->nr_scanned inc'ed. Actually, it would prevent
from adding pressure on slab shrink since excessive sc->nr_scanned would
prevent from scan->priority raise.
The bonnie test doesn't show this would change the behavior of slab
shrinkers.
mm: init: report memory auto-initialization features at boot time
Print the currently enabled stack and heap initialization modes.
Stack initialization is enabled by a config flag, while heap
initialization is configured at boot time with defaults being set in the
config. It's more convenient for the user to have all information about
these hardening measures in one place at boot, so the user can reason
about the expected behavior of the running system.
The possible options for stack are:
- "all" for CONFIG_INIT_STACK_ALL;
- "byref_all" for CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL;
- "byref" for CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF;
- "__user" for CONFIG_GCC_PLUGIN_STRUCTLEAK_USER;
- "off" otherwise.
Depending on the values of init_on_alloc and init_on_free boottime options
we also report "heap alloc" and "heap free" as "on"/"off".
In the init_on_free mode initializing pages at boot time may take a while,
so print a notice about that as well. This depends on how much memory is
installed, the memory bandwidth, etc. On a relatively modern x86 system,
it takes about 0.75s/GB to wipe all memory:
[ 0.418722] mem auto-init: stack:byref_all, heap alloc:off, heap free:on
[ 0.419765] mem auto-init: clearing system memory may take some time...
[ 12.376605] Memory: 16408564K/16776672K available (14339K kernel code, 1397K rwdata, 3756K rodata, 1636K init, 11460K bss, 368108K reserved, 0K cma-reserved)
Link: http://lkml.kernel.org/r/20190617151050.92663-3-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Suggested-by: Kees Cook <keescook@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: James Morris <jmorris@namei.org> Cc: Jann Horn <jannh@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Sandeep Patil <sspatil@android.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Kaiwan N Billimoria <kaiwan@kaiwantech.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options
Patch series "add init_on_alloc/init_on_free boot options", v10.
Provide init_on_alloc and init_on_free boot options.
These are aimed at preventing possible information leaks and making the
control-flow bugs that depend on uninitialized values more deterministic.
Enabling either of the options guarantees that the memory returned by the
page allocator and SL[AU]B is initialized with zeroes. SLOB allocator
isn't supported at the moment, as its emulation of kmem caches complicates
handling of SLAB_TYPESAFE_BY_RCU caches correctly.
Enabling init_on_free also guarantees that pages and heap objects are
initialized right after they're freed, so it won't be possible to access
stale data by using a dangling pointer.
As suggested by Michal Hocko, right now we don't let the heap users to
disable initialization for certain allocations. There's not enough
evidence that doing so can speed up real-life cases, and introducing ways
to opt-out may result in things going out of control.
This patch (of 2):
The new options are needed to prevent possible information leaks and make
control-flow bugs that depend on uninitialized values more deterministic.
This is expected to be on-by-default on Android and Chrome OS. And it
gives the opportunity for anyone else to use it under distros too via the
boot args. (The init_on_free feature is regularly requested by folks
where memory forensics is included in their threat models.)
init_on_alloc=1 makes the kernel initialize newly allocated pages and heap
objects with zeroes. Initialization is done at allocation time at the
places where checks for __GFP_ZERO are performed.
init_on_free=1 makes the kernel initialize freed pages and heap objects
with zeroes upon their deletion. This helps to ensure sensitive data
doesn't leak via use-after-free accesses.
Both init_on_alloc=1 and init_on_free=1 guarantee that the allocator
returns zeroed memory. The two exceptions are slab caches with
constructors and SLAB_TYPESAFE_BY_RCU flag. Those are never
zero-initialized to preserve their semantics.
Both init_on_alloc and init_on_free default to zero, but those defaults
can be overridden with CONFIG_INIT_ON_ALLOC_DEFAULT_ON and
CONFIG_INIT_ON_FREE_DEFAULT_ON.
If either SLUB poisoning or page poisoning is enabled, those options take
precedence over init_on_alloc and init_on_free: initialization is only
applied to unpoisoned allocations.
Slowdown for the new features compared to init_on_free=0, init_on_alloc=0:
hackbench, init_on_free=1: +7.62% sys time (st.err 0.74%)
hackbench, init_on_alloc=1: +7.75% sys time (st.err 2.14%)
Linux build with -j12, init_on_free=1: +8.38% wall time (st.err 0.39%)
Linux build with -j12, init_on_free=1: +24.42% sys time (st.err 0.52%)
Linux build with -j12, init_on_alloc=1: -0.13% wall time (st.err 0.42%)
Linux build with -j12, init_on_alloc=1: +0.57% sys time (st.err 0.40%)
The slowdown for init_on_free=0, init_on_alloc=0 compared to the baseline
is within the standard error.
The new features are also going to pave the way for hardware memory
tagging (e.g. arm64's MTE), which will require both on_alloc and on_free
hooks to set the tags for heap objects. With MTE, tagging will have the
same cost as memory initialization.
Although init_on_free is rather costly, there are paranoid use-cases where
in-memory data lifetime is desired to be minimized. There are various
arguments for/against the realism of the associated threat models, but
given that we'll need the infrastructure for MTE anyway, and there are
people who want wipe-on-free behavior no matter what the performance cost,
it seems reasonable to include it in this series.
[glider@google.com: v8] Link: http://lkml.kernel.org/r/20190626121943.131390-2-glider@google.com
[glider@google.com: v9] Link: http://lkml.kernel.org/r/20190627130316.254309-2-glider@google.com
[glider@google.com: v10] Link: http://lkml.kernel.org/r/20190628093131.199499-2-glider@google.com Link: http://lkml.kernel.org/r/20190617151050.92663-2-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.cz> [page and dmapool parts Acked-by: James Morris <jamorris@linux.microsoft.com>] Cc: Christoph Lameter <cl@linux.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Sandeep Patil <sspatil@android.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Jann Horn <jannh@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arm64: move jump_label_init() before parse_early_param()
While jump_label_init() was moved earlier in the boot process in efd9e03facd0 ("arm64: Use static keys for CPU features"), it wasn't early
enough for early params to use it. The old state of things was as
described here...
init/main.c calls out to arch-specific things before general jump label
and early param handling:
This moves arm64 jump_label_init() from smp_prepare_boot_cpu() to
setup_arch(), as done already on x86, in preparation from early param
usage in the init_on_alloc/free() series:
https://lkml.kernel.org/r/1561572949.5154.81.camel@lca.pw
Link: http://lkml.kernel.org/r/201906271003.005303B52@keescook Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Qian Cai <cai@lca.pw> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nicholas Piggin [Fri, 12 Jul 2019 03:59:12 +0000 (20:59 -0700)]
mm/large system hash: clear hashdist when only one node with memory is booted
CONFIG_NUMA on 64-bit CPUs currently enables hashdist unconditionally even
when booting on single node machines. This causes the large system hashes
to be allocated with vmalloc, and mapped with small pages.
This change clears hashdist if only one node has come up with memory.
This results in the important large inode and dentry hashes using memblock
allocations. All others are within 4MB size up to about 128GB of RAM,
which allows them to be allocated from the linear map on most non-NUMA
images.
Other big hashes like futex and TCP should eventually be moved over to the
same style of allocation as those vfs caches that use HASH_EARLY if
!hashdist, so they don't exceed MAX_ORDER on very large non-NUMA images.
This brings dTLB misses for linux kernel tree `git diff` from ~45,000 to
~8,000 on a Kaby Lake KVM guest with 8MB dentry hash and mitigations=off
(performance is in the noise, under 1% difference, page tables are likely
to be well cached for this workload).
Link: http://lkml.kernel.org/r/20190605144814.29319-2-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/vmalloc.c: switch to WARN_ON() and move it under unlink_va()
Trigger a warning if an object that is about to be freed is detached. We
used to have a BUG_ON(), but even though it is considered as faulty
behaviour that is not a good reason to break a system.
Link: http://lkml.kernel.org/r/20190606120411.8298-5-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/vmalloc.c: get rid of one single unlink_va() when merge
It does not make sense to try to "unlink" the node that is definitely not
linked with a list nor tree. On the first merge step VA just points to
the previously disconnected busy area.
On the second step, check if the node has been merged and do "unlink" if
so, because now it points to an object that must be linked.
Link: http://lkml.kernel.org/r/20190606120411.8298-4-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: Hillf Danton <hdanton@sina.com> Reviewed-by: Roman Gushchin <guro@fb.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/vmalloc.c: preload a CPU with one object for split purpose
Refactor the NE_FIT_TYPE split case when it comes to an allocation of one
extra object. We need it in order to build a remaining space. The
preload is done per CPU in non-atomic context with GFP_KERNEL flags.
More permissive parameters can be beneficial for systems which are suffer
from high memory pressure or low memory condition. For example on my KVM
system(4xCPUs, no swap, 256MB RAM) i can simulate the failure of page
allocation with GFP_NOWAIT flags. Using "stress-ng" tool and starting N
workers spinning on fork() and exit(), i can trigger below trace:
Make mmu_notifier_register() safer by issuing a memory barrier before
registering a new notifier. This fixes a theoretical bug on weakly
ordered CPUs. For example, take this simplified use of notifiers by a
driver:
Once mmu_notifier_register() releases the mm locks, another thread can
invalidate a range:
mmu_notifier_invalidate_range()
...
hlist_for_each_entry_rcu(mn, &mm->mmu_notifiers, hlist) {
if (mn->ops->invalidate_range)
The read side relies on the data dependency between mn and ops to ensure
that the pointer is properly initialized. But the write side doesn't have
any dependency between (1) and (2), so they could be reordered and the
readers could dereference an invalid mn->ops. mmu_notifier_register()
does take all the mm locks before adding to the hlist, but those have
acquire semantics which isn't sufficient.
By calling hlist_add_head_rcu() instead of hlist_add_head() we update the
hlist using a store-release, ensuring that readers see prior
initialization of my_struct. This situation is better illustated by
litmus test MP+onceassign+derefonce.
Miguel Ojeda [Fri, 12 Jul 2019 03:58:47 +0000 (20:58 -0700)]
mm/memory.c: fail when offset == num in first check of __vm_map_pages()
If the caller asks us for offset == num, we should already fail in the
first check, i.e. the one testing for offsets beyond the object.
At the moment, we are failing on the second test anyway, since count
cannot be 0. Still, to agree with the comment of the first test, we
should first test it there.
Link: http://lkml.kernel.org/r/20190528193004.GA7744@gmail.com Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Souptick Joarder <jrdr.linux@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/pgtable: drop pgtable_t variable from pte_fn_t functions
Drop the pgtable_t variable from all implementation for pte_fn_t as none
of them use it. apply_to_pte_range() should stop computing it as well.
Should help us save some cycles.
Link: http://lkml.kernel.org/r/1556803126-26596-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Matthew Wilcox <willy@infradead.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <jglisse@redhat.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Fri, 12 Jul 2019 03:58:39 +0000 (20:58 -0700)]
unicore32: switch to generic version of pte allocation
Replace __get_free_page() and alloc_pages() calls with the generic
__pte_alloc_one_kernel() and __pte_alloc_one().
There is no functional change for the kernel PTE allocation.
The difference for the user PTEs, is that the clear_pte_table() is now
called after pgtable_page_ctor() and the addition of __GFP_ACCOUNT to the
GFP flags.
The pte_free() and pte_free_kernel() versions are identical to the generic
ones and can be simply dropped.
Link: http://lkml.kernel.org/r/1557296232-15361-15-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Guo Ren <ren_guo@c-sky.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Fri, 12 Jul 2019 03:58:31 +0000 (20:58 -0700)]
riscv: switch to generic version of pte allocation
The only difference between the generic and RISC-V implementation of PTE
allocation is the usage of __GFP_RETRY_MAYFAIL for both kernel and user
PTEs and the absence of __GFP_ACCOUNT for the user PTEs.
The conversion to the generic version removes the __GFP_RETRY_MAYFAIL and
ensures that GFP_ACCOUNT is used for the user PTE allocations.
The pte_free() and pte_free_kernel() versions are identical to the generic
ones and can be simply dropped.
Link: http://lkml.kernel.org/r/1557296232-15361-13-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Fri, 12 Jul 2019 03:58:18 +0000 (20:58 -0700)]
nds32: switch to generic version of pte allocation
The nds32 implementation of pte_alloc_one_kernel() differs from the
generic in the use of __GFP_RETRY_MAYFAIL flag, which is removed after the
conversion.
The nds32 version of pte_alloc_one() missed the call to
pgtable_page_ctor() and also used __GFP_RETRY_MAYFAIL. Switching it to
use generic __pte_alloc_one() for the PTE page allocation ensures that
page table constructor is run and the user page tables are allocated with
__GFP_ACCOUNT.
The conversion to the generic version of pte_free_kernel() removes the
NULL check for pte.
The pte_free() version on nds32 is identical to the generic one and can be
simply dropped.
Link: http://lkml.kernel.org/r/1557296232-15361-10-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Fri, 12 Jul 2019 03:58:10 +0000 (20:58 -0700)]
m68k: sun3: switch to generic version of pte allocation
The sun3 MMU variant of m68k uses GFP_KERNEL to allocate a PTE page and
then memset(0) or clear_highpage() to clear it.
This is equivalent to allocating the page with GFP_KERNEL | __GFP_ZERO,
which allows replacing sun3 implementation of pte_alloc_one() and
pte_alloc_one_kernel() with the generic ones.
The pte_free() and pte_free_kernel() versions are identical to the generic
ones and can be simply dropped.
Link: http://lkml.kernel.org/r/1557296232-15361-8-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Fri, 12 Jul 2019 03:58:06 +0000 (20:58 -0700)]
csky: switch to generic version of pte allocation
The csky implementation pte_alloc_one(), pte_free_kernel() and pte_free()
is identical to the generic except of lack of __GFP_ACCOUNT for the user
PTEs allocation.
Switch csky to use generic version of these functions.
The csky implementation of pte_alloc_one_kernel() is not replaced because
it does not clear the allocated page but rather sets each PTE in it to a
non-zero value.
The pte_free_kernel() and pte_free() versions on csky are identical to the
generic ones and can be simply dropped.
Link: http://lkml.kernel.org/r/1557296232-15361-6-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Guo Ren <ren_guo@c-sky.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Fri, 12 Jul 2019 03:58:02 +0000 (20:58 -0700)]
arm64: switch to generic version of pte allocation
The PTE allocations in arm64 are identical to the generic ones modulo the
GFP flags.
Using the generic pte_alloc_one() functions ensures that the user page
tables are allocated with __GFP_ACCOUNT set.
The arm64 definition of PGALLOC_GFP is removed and replaced with
GFP_PGTABLE_USER for p[gum]d_alloc_one() for the user page tables and
GFP_PGTABLE_KERNEL for the kernel page tables. The KVM memory cache is now
using GFP_PGTABLE_USER.
The mappings created with create_pgd_mapping() are now using
GFP_PGTABLE_KERNEL.
The conversion to the generic version of pte_free_kernel() removes the NULL
check for pte.
The pte_free() version on arm64 is identical to the generic one and
can be simply dropped.
[cai@lca.pw: fix a bogus GFP flag in pgd_alloc()] Link: https://lore.kernel.org/r/1559656836-24940-1-git-send-email-cai@lca.pw/
[and fix it more] Link: https://lore.kernel.org/linux-mm/20190617151252.GF16810@rapoport-lnx/ Link: http://lkml.kernel.org/r/1557296232-15361-5-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Fri, 12 Jul 2019 03:57:57 +0000 (20:57 -0700)]
arm: switch to generic version of pte allocation
Replace __get_free_page() and alloc_pages() calls with the generic
__pte_alloc_one_kernel() and __pte_alloc_one().
There is no functional change for the kernel PTE allocation.
The difference for the user PTEs, is that the clear_pte_table() is now
called after pgtable_page_ctor() and the addition of __GFP_ACCOUNT to the
GFP flags.
The conversion to the generic version of pte_free_kernel() removes the NULL
check for pte.
The pte_free() version on arm is identical to the generic one and can be
simply dropped.
Link: http://lkml.kernel.org/r/1557296232-15361-4-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most architectures have identical or very similar implementation of
pte_alloc_one_kernel(), pte_alloc_one(), pte_free_kernel() and
pte_free().
Add a generic implementation that can be reused across architectures and
enable its use on x86.
The generic implementation uses
GFP_KERNEL | __GFP_ZERO
for the kernel page tables and
GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT
for the user page tables.
The "base" functions for PTE allocation, namely __pte_alloc_one_kernel()
and __pte_alloc_one() are intended for the architectures that require
additional actions after actual memory allocation or must use non-default
GFP flags.
x86 is switched to use generic pte_alloc_one_kernel(), pte_free_kernel() and
pte_free().
x86 still implements pte_alloc_one() to allow run-time control of GFP
flags required for "userpte" command line option.
Link: http://lkml.kernel.org/r/1557296232-15361-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andy Lutomirski [Fri, 12 Jul 2019 03:57:43 +0000 (20:57 -0700)]
mm/gup.c: remove some BUG_ONs from get_gate_page()
If we end up without a PGD or PUD entry backing the gate area, don't BUG
-- just fail gracefully.
It's not entirely implausible that this could happen some day on x86. It
doesn't right now even with an execute-only emulated vsyscall page because
the fixmap shares the PUD, but the core mm code shouldn't rely on that
particular detail to avoid OOPSing.
Link: http://lkml.kernel.org/r/a1d9f4efb75b9d464e59fd6af00104b21c58f6f7.1561610798.git.luto@kernel.org Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pingfan Liu [Fri, 12 Jul 2019 03:57:39 +0000 (20:57 -0700)]
mm/gup: speed up check_and_migrate_cma_pages() on huge page
Both hugetlb and thp locate on the same migration type of pageblock, since
they are allocated from a free_list[]. Based on this fact, it is enough
to check on a single subpage to decide the migration type of the whole
huge page. By this way, it saves (2M/4K - 1) times loop for pmd_huge on
x86, similar on other archs.
Furthermore, when executing isolate_huge_page(), it avoid taking global
hugetlb_lock many times, and meanless remove/add to the local link list
cma_page_list.
[akpm@linux-foundation.org: make `i' and `step' unsigned] Link: http://lkml.kernel.org/r/1561612545-28997-1-git-send-email-kernelfans@gmail.com Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Keith Busch <keith.busch@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: switch gup_hugepte to use try_get_compound_head
This applies the overflow fixes from 8fde12ca79aff ("mm: prevent
get_user_pages() from overflowing page refcount") to the powerpc hugepd
code and brings it back in sync with the other GUP cases.
Link: http://lkml.kernel.org/r/20190625143715.1689-16-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: consolidate the get_user_pages* implementations
Always build mm/gup.c so that we don't have to provide separate nommu
stubs. Also merge the get_user_pages_fast and __get_user_pages_fast stubs
when HAVE_FAST_GUP into the main implementations, which will never call
the fast path if HAVE_FAST_GUP is not set.
This also ensures the new put_user_pages* helpers are available for nommu,
as those are currently missing, which would create a problem as soon as we
actually grew users for it.
Link: http://lkml.kernel.org/r/20190625143715.1689-13-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This moves the actually exported functions towards the end of the file,
and reorders some functions to be in more logical blocks as a preparation
for moving various stubs inline into the main functionality using
IS_ENABLED().
Link: http://lkml.kernel.org/r/20190625143715.1689-12-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: rename CONFIG_HAVE_GENERIC_GUP to CONFIG_HAVE_FAST_GUP
We only support the generic GUP now, so rename the config option to
be more clear, and always use the mm/Kconfig definition of the
symbol and select it from the arch Kconfigs.
Link: http://lkml.kernel.org/r/20190625143715.1689-11-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The mips code is mostly equivalent to the generic one, minus various
bugfixes and an arch override for gup_fast_permitted.
Note that this defines ARCH_HAS_PTE_SPECIAL for mips as mips has
pte_special and pte_mkspecial implemented and used in the existing gup
code. They are no-op stubs, though which makes me a little unsure if this
is really right thing to do.
Note that this also adds back a missing cpu_has_dc_aliases check for
__get_user_pages_fast, which the old code was only doing for
get_user_pages_fast. This clearly looks like an oversight, as any
condition that makes get_user_pages_fast unsafe also applies to
__get_user_pages_fast.
[hch@lst.de: MIPS: don't select ARCH_HAS_PTE_SPECIAL] Link: http://lkml.kernel.org/r/20190701151818.32227-3-hch@lst.de Link: http://lkml.kernel.org/r/20190625143715.1689-5-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: lift the x86_32 PAE version of gup_get_pte to common code
The split low/high access is the only non-READ_ONCE version of gup_get_pte
that did show up in the various arch implemenations. Lift it to common
code and drop the ifdef based arch override.
Link: http://lkml.kernel.org/r/20190625143715.1689-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pass in the already calculated end value instead of recomputing it, and
leave the end > start check in the callers instead of duplicating them in
the arch code.
Link: http://lkml.kernel.org/r/20190625143715.1689-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: use untagged_addr() for get_user_pages_fast addresses
Patch series "switch the remaining architectures to use generic GUP", v4.
A series to switch mips, sh and sparc64 to use the generic GUP code so
that we only have one codebase to touch for further improvements to this
code.
This patch (of 16):
This will allow sparc64, or any future architecture with memory tagging to
override its tags for get_user_pages and get_user_pages_fast.
Link: http://lkml.kernel.org/r/20190625143715.1689-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Cc: Paul Burton <paul.burton@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: David Miller <davem@davemloft.net> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Waiman Long [Fri, 12 Jul 2019 03:56:38 +0000 (20:56 -0700)]
mm, memcg: add a memcg_slabinfo debugfs file
There are concerns about memory leaks from extensive use of memory cgroups
as each memory cgroup creates its own set of kmem caches. There is a
possiblity that the memcg kmem caches may remain even after the memory
cgroups have been offlined. Therefore, it will be useful to show the
status of each of memcg kmem caches.
This patch introduces a new <debugfs>/memcg_slabinfo file which is
somewhat similar to /proc/slabinfo in format, but lists only information
about kmem caches that have child memcg kmem caches. Information
available in /proc/slabinfo are not repeated in memcg_slabinfo.
The css id of the memcg is also listed. If a memcg is not online,
the tag ":dead" will be attached as shown above.
[longman@redhat.com: memcg: add ":deact" tag for reparented kmem caches in memcg_slabinfo] Link: http://lkml.kernel.org/r/20190621173005.31514-1-longman@redhat.com
[longman@redhat.com: set the flag in the common code as suggested by Roman] Link: http://lkml.kernel.org/r/20190627184324.5875-1-longman@redhat.com Link: http://lkml.kernel.org/r/20190619171621.26209-1-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Suggested-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Roman Gushchin [Fri, 12 Jul 2019 03:56:34 +0000 (20:56 -0700)]
mm: memcg/slab: reparent memcg kmem_caches on cgroup removal
Let's reparent non-root kmem_caches on memcg offlining. This allows us to
release the memory cgroup without waiting for the last outstanding kernel
object (e.g. dentry used by another application).
Since the parent cgroup is already charged, everything we need to do is to
splice the list of kmem_caches to the parent's kmem_caches list, swap the
memcg pointer, drop the css refcounter for each kmem_cache and adjust the
parent's css refcounter.
Please, note that kmem_cache->memcg_params.memcg isn't a stable pointer
anymore. It's safe to read it under rcu_read_lock(), cgroup_mutex held,
or any other way that protects the memory cgroup from being released.
We can race with the slab allocation and deallocation paths. It's not a
big problem: parent's charge and slab global stats are always correct, and
we don't care anymore about the child usage and global stats. The child
cgroup is already offline, so we don't use or show it anywhere.
Local slab stats (NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE) aren't
used anywhere except count_shadow_nodes(). But even there it won't break
anything: after reparenting "nodes" will be 0 on child level (because
we're already reparenting shrinker lists), and on parent level page stats
always were 0, and this patch won't change anything.
[guro@fb.com: properly handle kmem_caches reparented to root_mem_cgroup] Link: http://lkml.kernel.org/r/20190620213427.1691847-1-guro@fb.com Link: http://lkml.kernel.org/r/20190611231813.3148843-11-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Roman Gushchin [Fri, 12 Jul 2019 03:56:31 +0000 (20:56 -0700)]
mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages
Every slab page charged to a non-root memory cgroup has a pointer to the
memory cgroup and holds a reference to it, which protects a non-empty
memory cgroup from being released. At the same time the page has a
pointer to the corresponding kmem_cache, and also hold a reference to the
kmem_cache. And kmem_cache by itself holds a reference to the cgroup.
So there is clearly some redundancy, which allows to stop setting the
page->mem_cgroup pointer and rely on getting memcg pointer indirectly via
kmem_cache. Further it will allow to change this pointer easier, without
a need to go over all charged pages.
So let's stop setting page->mem_cgroup pointer for slab pages, and stop
using the css refcounter directly for protecting the memory cgroup from
going away. Instead rely on kmem_cache as an intermediate object.
Make sure that vmstats and shrinker lists are working as previously, as
well as /proc/kpagecgroup interface.
Link: http://lkml.kernel.org/r/20190611231813.3148843-10-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently each charged slab page holds a reference to the cgroup to which
it's charged. Kmem_caches are held by the memcg and are released all
together with the memory cgroup. It means that none of kmem_caches are
released unless at least one reference to the memcg exists, which is very
far from optimal.
Let's rework it in a way that allows releasing individual kmem_caches as
soon as the cgroup is offline, the kmem_cache is empty and there are no
pending allocations.
To make it possible, let's introduce a new percpu refcounter for non-root
kmem caches. The counter is initialized to the percpu mode, and is
switched to the atomic mode during kmem_cache deactivation. The counter
is bumped for every charged page and also for every running allocation.
So the kmem_cache can't be released unless all allocations complete.
To shutdown non-active empty kmem_caches, let's reuse the work queue,
previously used for the kmem_cache deactivation. Once the reference
counter reaches 0, let's schedule an asynchronous kmem_cache release.
* I used the following simple approach to test the performance
(stolen from another patchset by T. Harding):
time find / -name fname-no-exist
echo 2 > /proc/sys/vm/drop_caches
repeat 10 times
Results:
orig patched
real 0m1.455s real 0m1.355s
user 0m0.206s user 0m0.219s
sys 0m0.855s sys 0m0.807s
real 0m1.487s real 0m1.699s
user 0m0.221s user 0m0.256s
sys 0m0.806s sys 0m0.948s
real 0m1.515s real 0m1.505s
user 0m0.183s user 0m0.215s
sys 0m0.876s sys 0m0.858s
real 0m1.291s real 0m1.380s
user 0m0.193s user 0m0.198s
sys 0m0.843s sys 0m0.786s
real 0m1.364s real 0m1.374s
user 0m0.180s user 0m0.182s
sys 0m0.868s sys 0m0.806s
real 0m1.352s real 0m1.312s
user 0m0.201s user 0m0.212s
sys 0m0.820s sys 0m0.761s
real 0m1.302s real 0m1.349s
user 0m0.205s user 0m0.203s
sys 0m0.803s sys 0m0.792s
real 0m1.334s real 0m1.301s
user 0m0.194s user 0m0.201s
sys 0m0.806s sys 0m0.779s
real 0m1.426s real 0m1.434s
user 0m0.216s user 0m0.181s
sys 0m0.824s sys 0m0.864s
real 0m1.350s real 0m1.295s
user 0m0.200s user 0m0.190s
sys 0m0.842s sys 0m0.811s
So it looks like the difference is not noticeable in this test.
[cai@lca.pw: fix an use-after-free in kmemcg_workfn()] Link: http://lkml.kernel.org/r/1560977573-10715-1-git-send-email-cai@lca.pw Link: http://lkml.kernel.org/r/20190611231813.3148843-9-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Roman Gushchin [Fri, 12 Jul 2019 03:56:24 +0000 (20:56 -0700)]
mm: memcg/slab: synchronize access to kmem_cache dying flag using a spinlock
Currently the memcg_params.dying flag and the corresponding workqueue used
for the asynchronous deactivation of kmem_caches is synchronized using the
slab_mutex.
It makes impossible to check this flag from the irq context, which will be
required in order to implement asynchronous release of kmem_caches.
So let's switch over to the irq-save flavor of the spinlock-based
synchronization.
Link: http://lkml.kernel.org/r/20190611231813.3148843-8-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Roman Gushchin [Fri, 12 Jul 2019 03:56:20 +0000 (20:56 -0700)]
mm: memcg/slab: don't check the dying flag on kmem_cache creation
There is no point in checking the root_cache->memcg_params.dying flag on
kmem_cache creation path. New allocations shouldn't be performed using a
dead root kmem_cache, so no new memcg kmem_cache creation can be scheduled
after the flag is set. And if it was scheduled before,
flush_memcg_workqueue() will wait for it anyway.
So let's drop this check to simplify the code.
Link: http://lkml.kernel.org/r/20190611231813.3148843-7-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Roman Gushchin [Fri, 12 Jul 2019 03:56:16 +0000 (20:56 -0700)]
mm: memcg/slab: unify SLAB and SLUB page accounting
Currently the page accounting code is duplicated in SLAB and SLUB
internals. Let's move it into new (un)charge_slab_page helpers in the
slab_common.c file. These helpers will be responsible for statistics
(global and memcg-aware) and memcg charging. So they are replacing direct
memcg_(un)charge_slab() calls.
Link: http://lkml.kernel.org/r/20190611231813.3148843-6-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's separate the page counter modification code out of
__memcg_kmem_uncharge() in a way similar to what
__memcg_kmem_charge() and __memcg_kmem_charge_memcg() work.
This will allow to reuse this code later using a new
memcg_kmem_uncharge_memcg() wrapper, which calls
__memcg_kmem_uncharge_memcg() if memcg_kmem_enabled()
check is passed.
Link: http://lkml.kernel.org/r/20190611231813.3148843-5-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently SLUB uses a work scheduled after an RCU grace period to
deactivate a non-root kmem_cache. This mechanism can be reused for
kmem_caches release, but requires generalization for SLAB case.
Introduce kmemcg_cache_deactivate() function, which calls
allocator-specific __kmem_cache_deactivate() and schedules execution of
__kmem_cache_deactivate_after_rcu() with all necessary locks in a worker
context after an rcu grace period.
Here is the new calling scheme:
kmemcg_cache_deactivate()
__kmemcg_cache_deactivate() SLAB/SLUB-specific
kmemcg_rcufn() rcu
kmemcg_workfn() work
__kmemcg_cache_deactivate_after_rcu() SLAB/SLUB-specific
For consistency, all allocator-specific functions start with "__".
Link: http://lkml.kernel.org/r/20190611231813.3148843-4-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Roman Gushchin [Fri, 12 Jul 2019 03:56:06 +0000 (20:56 -0700)]
mm: memcg/slab: rename slab delayed deactivation functions and fields
The delayed work/rcu deactivation infrastructure of non-root kmem_caches
can be also used for asynchronous release of these objects. Let's get rid
of the word "deactivation" in corresponding names to make the code look
better after generalization.
It's easier to make the renaming first, so that the generalized code will
look consistent from scratch.
And RCU/delayed work callbacks in slab common code:
kmemcg_deactivate_rcufn -> kmemcg_rcufn
kmemcg_deactivate_workfn -> kmemcg_workfn
This patch contains no functional changes, only renamings.
Link: http://lkml.kernel.org/r/20190611231813.3148843-3-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Roman Gushchin [Fri, 12 Jul 2019 03:56:02 +0000 (20:56 -0700)]
mm: memcg/slab: postpone kmem_cache memcg pointer initialization to memcg_link_cache()
Patch series "mm: reparent slab memory on cgroup removal", v7.
# Why do we need this?
We've noticed that the number of dying cgroups is steadily growing on most
of our hosts in production. The following investigation revealed an issue
in the userspace memory reclaim code [1], accounting of kernel stacks [2],
and also the main reason: slab objects.
The underlying problem is quite simple: any page charged to a cgroup holds
a reference to it, so the cgroup can't be reclaimed unless all charged
pages are gone. If a slab object is actively used by other cgroups, it
won't be reclaimed, and will prevent the origin cgroup from being
reclaimed.
Slab objects, and first of all vfs cache, is shared between cgroups, which
are using the same underlying fs, and what's even more important, it's
shared between multiple generations of the same workload. So if something
is running periodically every time in a new cgroup (like how systemd
works), we do accumulate multiple dying cgroups.
Strictly speaking pagecache isn't different here, but there is a key
difference: we disable protection and apply some extra pressure on LRUs of
dying cgroups, and these LRUs contain all charged pages. My experiments
show that with the disabled kernel memory accounting the number of dying
cgroups stabilizes at a relatively small number (~100, depends on memory
pressure and cgroup creation rate), and with kernel memory accounting it
grows pretty steadily up to several thousands.
Memory cgroups are quite complex and big objects (mostly due to percpu
stats), so it leads to noticeable memory losses. Memory occupied by dying
cgroups is measured in hundreds of megabytes. I've even seen a host with
more than 100Gb of memory wasted for dying cgroups. It leads to a
degradation of performance with the uptime, and generally limits the usage
of cgroups.
My previous attempt [3] to fix the problem by applying extra pressure on
slab shrinker lists caused a regressions with xfs and ext4, and has been
reverted [4]. The following attempts to find the right balance [5, 6]
were not successful.
So instead of trying to find a maybe non-existing balance, let's do
reparent accounted slab caches to the parent cgroup on cgroup removal.
# Implementation approach
There is however a significant problem with reparenting of slab memory:
there is no list of charged pages. Some of them are in shrinker lists,
but not all. Introducing of a new list is really not an option.
But fortunately there is a way forward: every slab page has a stable
pointer to the corresponding kmem_cache. So the idea is to reparent
kmem_caches instead of slab pages.
It's actually simpler and cheaper, but requires some underlying changes:
1) Make kmem_caches to hold a single reference to the memory cgroup,
instead of a separate reference per every slab page.
2) Stop setting page->mem_cgroup pointer for memcg slab pages and use
page->kmem_cache->memcg indirection instead. It's used only on
slab page release, so performance overhead shouldn't be a big issue.
3) Introduce a refcounter for non-root slab caches. It's required to
be able to destroy kmem_caches when they become empty and release
the associated memory cgroup.
There is a bonus: currently we release all memcg kmem_caches all together
with the memory cgroup itself. This patchset allows individual
kmem_caches to be released as soon as they become inactive and free.
Some additional implementation details are provided in corresponding
commit messages.
# Results
Below is the average number of dying cgroups on two groups of our
production hosts. They do run some sort of web frontend workload, the
memory pressure is moderate. As we can see, with the kernel memory
reparenting the number stabilizes in 60s range; however with the original
version it grows almost linearly and doesn't show any signs of plateauing.
The difference in slab and percpu usage between patched and unpatched
versions also grows linearly. In 7 days it exceeded 200Mb.
[1]: commit 68600f623d69 ("mm: don't miss the last page because of round-off error")
[2]: commit 9b6f7e163cd0 ("mm: rework memcg kernel stack accounting")
[3]: commit 172b06c32b94 ("mm: slowly shrink slabs with a relatively small number of objects")
[4]: commit a9a238e83fbb ("Revert "mm: slowly shrink slabs with a relatively small number of objects")
[5]: https://lkml.org/lkml/2019/1/28/1865
[6]: https://marc.info/?l=linux-mm&m=155064763626437&w=2
This patch (of 10):
Initialize kmem_cache->memcg_params.memcg pointer in memcg_link_cache()
rather than in init_memcg_params().
Once kmem_cache will hold a reference to the memory cgroup, it will
simplify the refcounting.
For non-root kmem_caches memcg_link_cache() is always called before the
kmem_cache becomes visible to a user, so it's safe.
Link: http://lkml.kernel.org/r/20190611231813.3148843-2-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Waiman Long <longman@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Fri, 12 Jul 2019 03:55:59 +0000 (20:55 -0700)]
mm: memcontrol: dump memory.stat during cgroup OOM
The current cgroup OOM memory info dump doesn't include all the memory
we are tracking, nor does it give insight into what the VM tried to do
leading up to the OOM. All that useful info is in memory.stat.
Furthermore, the recursive printing for every child cgroup can
generate absurd amounts of data on the console for larger cgroup
trees, and it's not like we provide a per-cgroup breakdown during
global OOM kills.
When an OOM kill is triggered, print one set of recursive memory.stat
items at the level whose limit triggered the OOM condition.
The memory controller in cgroup v2 exposes memory.events file for each
memcg which shows the number of times events like low, high, max, oom
and oom_kill have happened for the whole tree rooted at that memcg.
Users can also poll or register notification to monitor the changes in
that file. Any event at any level of the tree rooted at memcg will
notify all the listeners along the path till root_mem_cgroup. There are
existing users which depend on this behavior.
However there are users which are only interested in the events
happening at a specific level of the memcg tree and not in the events in
the underlying tree rooted at that memcg. One such use-case is a
centralized resource monitor which can dynamically adjust the limits of
the jobs running on a system. The jobs can create their sub-hierarchy
for their own sub-tasks. The centralized monitor is only interested in
the events at the top level memcgs of the jobs as it can then act and
adjust the limits of the jobs. Using the current memory.events for such
centralized monitor is very inconvenient. The monitor will keep
receiving events which it is not interested and to find if the received
event is interesting, it has to read memory.event files of the next
level and compare it with the top level one. So, let's introduce
memory.events.local to the memcg which shows and notify for the events
at the memcg level.
Now, does memory.stat and memory.pressure need their local versions. IMHO
no due to the no internal process contraint of the cgroup v2. The
memory.stat file of the top level memcg of a job shows the stats and
vmevents of the whole tree. The local stats or vmevents of the top level
memcg will only change if there is a process running in that memcg but v2
does not allow that. Similarly for memory.pressure there will not be any
process in the internal nodes and thus no chance of local pressure.
Link: http://lkml.kernel.org/r/20190527174643.209172-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Chris Down <chris@chrisdown.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memcg, fsnotify: no oom-kill for remote memcg charging
Commit d46eb14b735b ("fs: fsnotify: account fsnotify metadata to
kmemcg") added remote memcg charging for fanotify and inotify event
objects. The aim was to charge the memory to the listener who is
interested in the events but without triggering the OOM killer.
Otherwise there would be security concerns for the listener.
At the time, oom-kill trigger was not in the charging path. A parallel
work added the oom-kill back to charging path i.e. commit 29ef680ae7c2
("memcg, oom: move out_of_memory back to the charge path"). So to not
trigger oom-killer in the remote memcg, explicitly add
__GFP_RETRY_MAYFAIL to the fanotigy and inotify event allocations.
Link: http://lkml.kernel.org/r/20190514212259.156585-2-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Roman Gushchin <guro@fb.com> Acked-by: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The documentation of __GFP_RETRY_MAYFAIL clearly mentioned that the OOM
killer will not be triggered and indeed the page alloc does not invoke OOM
killer for such allocations. However we do trigger memcg OOM killer for
__GFP_RETRY_MAYFAIL. Fix that. This flag will used later to not trigger
oom-killer in the charging path for fanotify and inotify event
allocations.
Link: http://lkml.kernel.org/r/20190514212259.156585-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Amir Goldstein <amir73il@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Roman Gushchin <guro@fb.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/mincore.c: fix race between swapoff and mincore
Via commit 4b3ef9daa4fc ("mm/swap: split swap cache into 64MB trunks"),
after swapoff, the address_space associated with the swap device will be
freed. So swap_address_space() users which touch the address_space need
some kind of mechanism to prevent the address_space from being freed
during accessing.
When mincore processes an unmapped range for swapped shmem pages, it
doesn't hold the lock to prevent swap device from being swapped off. So
the following race is possible:
The address space may be accessed after being freed.
To fix the race, get_swap_device()/put_swap_device() is used to enclose
find_get_page() to check whether the swap entry is valid and prevent the
swap device from being swapoff during accessing.
Link: http://lkml.kernel.org/r/20190611020510.28251-1-ying.huang@intel.com Fixes: 4b3ef9daa4fc ("mm/swap: split swap cache into 64MB trunks") Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Andrea Parri <andrea.parri@amarulasolutions.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Aaron Lu [Fri, 12 Jul 2019 03:55:41 +0000 (20:55 -0700)]
mm, swap: use rbtree for swap_extent
swap_extent is used to map swap page offset to backing device's block
offset. For a continuous block range, one swap_extent is used and all
these swap_extents are managed in a linked list.
These swap_extents are used by map_swap_entry() during swap's read and
write path. To find out the backing device's block offset for a page
offset, the swap_extent list will be traversed linearly, with
curr_swap_extent being used as a cache to speed up the search.
This works well as long as swap_extents are not huge or when the number
of processes that access swap device are few, but when the swap device
has many extents and there are a number of processes accessing the swap
device concurrently, it can be a problem. On one of our servers, the
disk's remaining size is tight:
$df -h
Filesystem Size Used Avail Use% Mounted on
... ...
/dev/nvme0n1p1 1.8T 1.3T 504G 72% /home/t4
When creating a 80G swapfile there, there are as many as 84656 swap
extents. The end result is, kernel spends abou 30% time in
map_swap_entry() and swap throughput is only 70MB/s.
As a comparison, when I used smaller sized swapfile, like 4G whose
swap_extent dropped to 2000, swap throughput is back to 400-500MB/s and
map_swap_entry() is about 3%.
One downside of using rbtree for swap_extent is, 'struct rbtree' takes
24 bytes while 'struct list_head' takes 16 bytes, that's 8 bytes more
for each swap_extent. For a swapfile that has 80k swap_extents, that
means 625KiB more memory consumed.
Test:
Since it's not possible to reboot that server, I can not test this patch
diretly there. Instead, I tested it on another server with NVMe disk.
I created a 20G swapfile on an NVMe backed XFS fs. By default, the
filesystem is quite clean and the created swapfile has only 2 extents.
Testing vanilla and this patch shows no obvious performance difference
when swapfile is not fragmented.
To see the patch's effects, I used some tweaks to manually fragment the
swapfile by breaking the extent at 1M boundary. This made the swapfile
have 20K extents.
swapout: the throughput of swap out, in KB/s, higher is better 1st
map_swap_entry: cpu cycles percent sampled by perf swapin: the
throughput of swap in, in KB/s, higher is better. 2nd map_swap_entry:
cpu cycles percent sampled by perf
nr_task=1 doesn't show any difference, this is due to the curr_swap_extent
can be effectively used to cache the correct swap extent for single task
workload.
mm/swap_state.c: simplify total_swapcache_pages() with get_swap_device()
total_swapcache_pages() may race with swapper_spaces[] allocation and
freeing. Previously, this is protected with a swapper_spaces[] specific
RCU mechanism. To simplify the logic/code complexity, it is replaced with
get/put_swap_device(). The code line number is reduced too. Although not
so important, the swapoff() performance improves too because one
synchronize_rcu() call during swapoff() is deleted.
[ying.huang@intel.com: fix bad swap file entry warning] Link: http://lkml.kernel.org/r/20190531024102.21723-1-ying.huang@intel.com Link: http://lkml.kernel.org/r/20190527082714.12151-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Andrea Parri <andrea.parri@amarulasolutions.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm, swap: fix race between swapoff and some swap operations
When swapin is performed, after getting the swap entry information from
the page table, system will swap in the swap entry, without any lock held
to prevent the swap device from being swapoff. This may cause the race
like below,
Because swapoff is usually done when system shutdown only, the race may
not hit many people in practice. But it is still a race need to be fixed.
To fix the race, get_swap_device() is added to check whether the specified
swap entry is valid in its swap device. If so, it will keep the swap
entry valid via preventing the swap device from being swapoff, until
put_swap_device() is called.
Because swapoff() is very rare code path, to make the normal path runs as
fast as possible, rcu_read_lock/unlock() and synchronize_rcu() instead of
reference count is used to implement get/put_swap_device(). >From
get_swap_device() to put_swap_device(), RCU reader side is locked, so
synchronize_rcu() in swapoff() will wait until put_swap_device() is
called.
In addition to swap_map, cluster_info, etc. data structure in the struct
swap_info_struct, the swap cache radix tree will be freed after swapoff,
so this patch fixes the race between swap cache looking up and swapoff
too.
Races between some other swap cache usages and swapoff are fixed too via
calling synchronize_rcu() between clearing PageSwapCache() and freeing
swap cache data structure.
Another possible method to fix this is to use preempt_off() +
stop_machine() to prevent the swap device from being swapoff when its data
structure is being accessed. The overhead in hot-path of both methods is
similar. The advantages of RCU based method are,
1. stop_machine() may disturb the normal execution code path on other
CPUs.
2. File cache uses RCU to protect its radix tree. If the similar
mechanism is used for swap cache too, it is easier to share code
between them.
3. RCU is used to protect swap cache in total_swapcache_pages() and
exit_swap_address_space() already. The two mechanisms can be
merged to simplify the logic.
Link: http://lkml.kernel.org/r/20190522015423.14418-1-ying.huang@intel.com Fixes: 235b62176712 ("mm/swap: add cluster lock") Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Andrea Parri <andrea.parri@amarulasolutions.com> Not-nacked-by: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yang Shi [Fri, 12 Jul 2019 03:55:29 +0000 (20:55 -0700)]
mm/filemap.c: correct the comment about VM_FAULT_RETRY
Commit 6b4c9f446981 ("filemap: drop the mmap_sem for all blocking
operations") changed when mmap_sem is dropped during filemap page fault
and when returning VM_FAULT_RETRY.
Correct the comment to reflect the change.
Link: http://lkml.kernel.org/r/1556234531-108228-1-git-send-email-yang.shi@linux.alibaba.com Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the callback 9p passes to read_cache_page to actually have the
proper type expected. Casting around function pointers can easily
hide typing bugs, and defeats control flow protection.
Link: http://lkml.kernel.org/r/20190520055731.24538-5-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
jffs2: pass the correct prototype to read_cache_page
Fix the callback jffs2 passes to read_cache_page to actually have the
proper type expected. Casting around function pointers can easily hide
typing bugs, and defeats control flow protection.
Link: http://lkml.kernel.org/r/20190520055731.24538-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/filemap.c: fix an overly long line in read_cache_page
Patch series "fix filler_t callback type mismatches", v2.
Casting mapping->a_ops->readpage to filler_t causes an indirect call
type mismatch with Control-Flow Integrity checking. This change fixes
the mismatch in read_cache_page_gfp and read_mapping_page by adding
using a NULL filler argument as an indication to call ->readpage
directly, and by passing the right parameter callbacks in nfs and jffs2.
This patch (of 4):
Code cleanup.
Link: http://lkml.kernel.org/r/20190520055731.24538-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm, debug_pagealloc: use a page type instead of page_ext flag
When debug_pagealloc is enabled, we currently allocate the page_ext
array to mark guard pages with the PAGE_EXT_DEBUG_GUARD flag. Now that
we have the page_type field in struct page, we can use that instead, as
guard pages are neither PageSlab nor mapped to userspace. This reduces
memory overhead when debug_pagealloc is enabled and there are no other
features requiring the page_ext array.
Link: http://lkml.kernel.org/r/20190603143451.27353-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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