Guenter Roeck [Mon, 21 Mar 2016 11:20:53 +0000 (04:20 -0700)]
unicore32: mm: Add missing parameter to arch_vma_access_permitted
unicore32 fails to compile with the following errors.
mm/memory.c: In function ‘__handle_mm_fault’:
mm/memory.c:3381: error:
too many arguments to function ‘arch_vma_access_permitted’
mm/gup.c: In function ‘check_vma_flags’:
mm/gup.c:456: error:
too many arguments to function ‘arch_vma_access_permitted’
mm/gup.c: In function ‘vma_permits_fault’:
mm/gup.c:640: error:
too many arguments to function ‘arch_vma_access_permitted’
Linus Torvalds [Fri, 12 Aug 2016 23:28:41 +0000 (16:28 -0700)]
Merge tag 'nfsd-4.8-1' of git://linux-nfs.org/~bfields/linux
Pull nfsd fixes from Bruce Fields:
"Fixes for the dentry refcounting leak I introduced in 4.8-rc1, and for
races in the LOCK code which appear to go back to the big nfsd state
lock removal from 3.17"
* tag 'nfsd-4.8-1' of git://linux-nfs.org/~bfields/linux:
nfsd: don't return an unhashed lock stateid after taking mutex
nfsd: Fix race between FREE_STATEID and LOCK
nfsd: fix dentry refcounting on create
Linus Torvalds [Fri, 12 Aug 2016 23:23:58 +0000 (16:23 -0700)]
Merge tag 'pm-4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"Two hibernation fixes allowing it to work with the recently added
randomization of the kernel identity mapping base on x86-64 and one
cpufreq driver regression fix.
Specifics:
- Fix the x86 identity mapping creation helpers to avoid the
assumption that the base address of the mapping will always be
aligned at the PGD level, as it may be aligned at the PUD level if
address space randomization is enabled (Rafael Wysocki).
- Fix the hibernation core to avoid executing tracing functions
before restoring the processor state completely during resume
(Thomas Garnier).
- Fix a recently introduced regression in the powernv cpufreq driver
that causes it to crash due to an out-of-bounds array access
(Akshay Adiga)"
* tag 'pm-4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / hibernate: Restore processor state before using per-CPU variables
x86/power/64: Always create temporary identity mapping correctly
cpufreq: powernv: Fix crash in gpstate_timer_handler()
Linus Torvalds [Fri, 12 Aug 2016 21:31:10 +0000 (14:31 -0700)]
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"This is bigger than usual - the reason is partly a pent-up stream of
fixes after the merge window and partly accidental. The fixes are:
- five patches to fix a boot failure on Andy Lutomirsky's laptop
- four SGI UV platform fixes
- KASAN fix
- warning fix
- documentation update
- swap entry definition fix
- pkeys fix
- irq stats fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic/x2apic, smp/hotplug: Don't use before alloc in x2apic_cluster_probe()
x86/efi: Allocate a trampoline if needed in efi_free_boot_services()
x86/boot: Rework reserve_real_mode() to allow multiple tries
x86/boot: Defer setup_real_mode() to early_initcall time
x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly
x86/boot: Run reserve_bios_regions() after we initialize the memory map
x86/irq: Do not substract irq_tlb_count from irq_call_count
x86/mm: Fix swap entry comment and macro
x86/mm/kaslr: Fix -Wformat-security warning
x86/mm/pkeys: Fix compact mode by removing protection keys' XSAVE buffer manipulation
x86/build: Reduce the W=1 warnings noise when compiling x86 syscall tables
x86/platform/UV: Fix kernel panic running RHEL kdump kernel on UV systems
x86/platform/UV: Fix problem with UV4 BIOS providing incorrect PXM values
x86/platform/UV: Fix bug with iounmap() of the UV4 EFI System Table causing a crash
x86/platform/UV: Fix problem with UV4 Socket IDs not being contiguous
x86/entry: Clarify the RF saving/restoring situation with SYSCALL/SYSRET
x86/mm: Disable preemption during CR3 read+write
x86/mm/KASLR: Increase BRK pages for KASLR memory randomization
x86/mm/KASLR: Fix physical memory calculation on KASLR memory randomization
x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text
Linus Torvalds [Fri, 12 Aug 2016 20:55:06 +0000 (13:55 -0700)]
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
"Misc fixes: a /dev/rtc regression fix, two APIC timer period
calibration fixes, an ARM clocksource driver fix and a NOHZ
power use regression fix"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/hpet: Fix /dev/rtc breakage caused by RTC cleanup
x86/timers/apic: Inform TSC deadline clockevent device about recalibration
x86/timers/apic: Fix imprecise timer interrupts by eliminating TSC clockevents frequency roundoff error
timers: Fix get_next_timer_interrupt() computation
clocksource/arm_arch_timer: Force per-CPU interrupt to be level-triggered
Thomas Garnier [Thu, 11 Aug 2016 21:49:29 +0000 (14:49 -0700)]
PM / hibernate: Restore processor state before using per-CPU variables
Restore the processor state before calling any other functions to
ensure per-CPU variables can be used with KASLR memory randomization.
Tracing functions use per-CPU variables (GS based on x86) and one was
called just before restoring the processor state fully. It resulted
in a double fault when both the tracing & the exception handler
functions tried to use a per-CPU variable.
Fixes: bb3632c6101b (PM / sleep: trace events for suspend/resume) Reported-and-tested-by: Borislav Petkov <bp@suse.de> Reported-by: Jiri Kosina <jikos@kernel.org> Tested-by: Rafael J. Wysocki <rafael@kernel.org> Tested-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Thomas Garnier <thgarnie@google.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Linus Torvalds [Fri, 12 Aug 2016 20:21:18 +0000 (13:21 -0700)]
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
"Mostly tooling fixes, plus two uncore-PMU fixes, an uprobes fix, a
perf-cgroups fix and an AUX events fix"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/uncore: Add enable_box for client MSR uncore
perf/x86/intel/uncore: Fix uncore num_counters
uprobes/x86: Fix RIP-relative handling of EVEX-encoded instructions
perf/core: Set cgroup in CPU contexts for new cgroup events
perf/core: Fix sideband list-iteration vs. event ordering NULL pointer deference crash
perf probe ppc64le: Fix probe location when using DWARF
perf probe: Add function to post process kernel trace events
tools: Sync cpufeatures headers with the kernel
toops: Sync tools/include/uapi/linux/bpf.h with the kernel
tools: Sync cpufeatures.h and vmx.h with the kernel
perf probe: Support signedness casting
perf stat: Avoid skew when reading events
perf probe: Fix module name matching
perf probe: Adjust map->reloc offset when finding kernel symbol from map
perf hists: Trim libtraceevent trace_seq buffers
perf script: Add 'bpf-output' field to usage message
Jeff Layton [Thu, 11 Aug 2016 14:37:39 +0000 (10:37 -0400)]
nfsd: don't return an unhashed lock stateid after taking mutex
nfsd4_lock will take the st_mutex before working with the stateid it
gets, but between the time when we drop the cl_lock and take the mutex,
the stateid could become unhashed (a'la FREE_STATEID). If that happens
the lock stateid returned to the client will be forgotten.
Fix this by first moving the st_mutex acquisition into
lookup_or_create_lock_state. Then, have it check to see if the lock
stateid is still hashed after taking the mutex. If it's not, then put
the stateid and try the find/create again.
Signed-off-by: Jeff Layton <jlayton@redhat.com> Tested-by: Alexey Kodanev <alexey.kodanev@oracle.com> Cc: stable@vger.kernel.org # feb9dad5 nfsd: Always lock state exclusively. Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Linus Torvalds [Fri, 12 Aug 2016 19:46:37 +0000 (12:46 -0700)]
Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
"Misc fixes: lockstat fix, futex fix on !MMU systems, big endian fix
for qrwlocks and a race fix for pvqspinlocks"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/pvqspinlock: Fix a bug in qstat_read()
locking/pvqspinlock: Fix double hash race
locking/qrwlock: Fix write unlock bug on big endian systems
futex: Assume all mappings are private on !MMU systems
Linus Torvalds [Fri, 12 Aug 2016 19:39:02 +0000 (12:39 -0700)]
Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fixes from Ingo Molnar:
"A fix for EFI capsules and an SGI UV platform fix"
* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi/capsule: Allocate whole capsule into virtual memory
x86/platform/uv: Skip UV runtime services mapping in the efi_runtime_disabled case
Linus Torvalds [Fri, 12 Aug 2016 19:32:24 +0000 (12:32 -0700)]
Merge tag 'nfs-for-4.8-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
"Highlights include:
- Stable patch from Olga to fix RPCSEC_GSS upcalls when the same user
needs multiple different security services (e.g. krb5i and krb5p).
- Stable patch to fix a regression introduced by the use of
SO_REUSEPORT, and that prevented the use of multiple different NFS
versions to the same server.
- TCP socket reconnection timer fixes.
- Patch from Neil to disable the use of IPv6 temporary addresses"
* tag 'nfs-for-4.8-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFSv4: Cap the transport reconnection timer at 1/2 lease period
NFSv4: Cleanup the setting of the nfs4 lease period
SUNRPC: Limit the reconnect backoff timer to the max RPC message timeout
SUNRPC: Fix reconnection timeouts
NFSv4.2: LAYOUTSTATS may return NFS4ERR_ADMIN/DELEG_REVOKED
SUNRPC: disable the use of IPv6 temporary addresses.
SUNRPC: allow for upcalls for same uid but different gss service
SUNRPC: Fix up socket autodisconnect
SUNRPC: Handle EADDRNOTAVAIL on connection failures
Linus Torvalds [Fri, 12 Aug 2016 19:28:23 +0000 (12:28 -0700)]
Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams:
- Fix for the nd_blk (NVDIMM Block Window Aperture) driver.
A spec clarification requires the driver to mask off reserved bits in
status register. This is tagged for -stable back to the v4.2 kernel.
- Fix for a kernel crash in the nvdimm unit tests when module loading
is interrupted with SIGTERM. Tagged for -stable since validation
efforts external to Intel use the unit tests for qualifying
backports.
- Add a new 'size' sysfs attribute for the BTT (NVDIMM Block
Translation Table) driver to make it symmetric with the other
namespace personality drivers (PFN and DAX) that provide a size
attribute for indicating how much namespace capacity is lost to
metadata.
The BTT change arrived at the start of the merge window and has
appeared in a -next release. It can technically wait for 4.9, but it
is small, fixes asymmetry in the libnvdimm-sysfs interface, and
something I would have squeezed into the v4.8 pull request had it
arrived a few days earlier.
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
tools/testing/nvdimm: fix SIGTERM vs hotplug crash
nvdimm, btt: add a size attribute for BTTs
libnvdimm, nd_blk: mask off reserved status bits
Linus Torvalds [Fri, 12 Aug 2016 19:26:59 +0000 (12:26 -0700)]
Merge tag 'sound-4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"A regression fix of HD-audio runtime PM and two USB quirks"
* tag 'sound-4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: hda - Manage power well properly for resume
ALSA: usb-audio: Add quirk for ELP HD USB Camera
ALSA: usb-audio: Add a sample rate quirk for Creative Live! Cam Socialize HD (VF0610)
Linus Torvalds [Fri, 12 Aug 2016 19:09:44 +0000 (12:09 -0700)]
Merge tag 'powerpc-4.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"Some powerpc fixes for 4.8:
Misc:
- powerpc/vdso: Fix build rules to rebuild vdsos correctly from Nicholas Piggin
- powerpc/ptrace: Fix coredump since ptrace TM changes from Cyril Bur
- powerpc/32: Fix csum_partial_copy_generic() from Christophe Leroy
- cxl: Set psl_fir_cntl to production environment value from Frederic Barrat
- powerpc/eeh: Switch to conventional PCI address output in EEH log from Guilherme G. Piccoli
- cxl: Use fixed width predefined types in data structure. from Philippe Bergheaud
- powerpc/vdso: Add missing include file from Guenter Roeck
- powerpc: Fix unused function warning 'lmb_to_memblock' from Alastair D'Silva
- powerpc/powernv/ioda: Fix TCE invalidate to work in real mode again from Alexey Kardashevskiy
- powerpc/cell: Add missing error code in spufs_mkgang() from Dan Carpenter
- crypto: crc32c-vpmsum - Convert to CPU feature based module autoloading from Anton Blanchard
- powerpc/pasemi: Fix coherent_dma_mask for dma engine from Darren Stevens
Benjamin Herrenschmidt:
- powerpc/32: Fix crash during static key init
- powerpc: Update obsolete comment in setup_32.c about early_init()
- powerpc: Print the kernel load address at the end of prom_init()
- powerpc/pnv/pci: Fix incorrect PE reservation attempt on some 64-bit BARs
- powerpc/xics: Properly set Edge/Level type and enable resend
Mahesh Salgaonkar:
- powerpc/book3s: Fix MCE console messages for unrecoverable MCE.
- powerpc/powernv: Fix MCE handler to avoid trashing CR0/CR1 registers.
- powerpc/powernv: Move IDLE_STATE_ENTER_SEQ macro to cpuidle.h
- powerpc/powernv: Load correct TOC pointer while waking up from winkle.
Andrew Donnellan:
- cxl: Fix sparse warnings
- cxl: Fix NULL dereference in cxl_context_init() on PowerVM guests
Michael Ellerman:
- selftests/powerpc: Specify we expect to build with std=gnu99
- powerpc/Makefile: Use cflags-y/aflags-y for setting endian options
- powerpc/pci: Fix endian bug in fixed PHB numbering"
* tag 'powerpc-4.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (26 commits)
selftests/powerpc: Specify we expect to build with std=gnu99
powerpc/vdso: Fix build rules to rebuild vdsos correctly
powerpc/Makefile: Use cflags-y/aflags-y for setting endian options
powerpc/32: Fix crash during static key init
powerpc: Update obsolete comment in setup_32.c about early_init()
powerpc: Print the kernel load address at the end of prom_init()
powerpc/ptrace: Fix coredump since ptrace TM changes
powerpc/32: Fix csum_partial_copy_generic()
cxl: Set psl_fir_cntl to production environment value
powerpc/pnv/pci: Fix incorrect PE reservation attempt on some 64-bit BARs
powerpc/book3s: Fix MCE console messages for unrecoverable MCE.
powerpc/pci: Fix endian bug in fixed PHB numbering
powerpc/eeh: Switch to conventional PCI address output in EEH log
cxl: Fix sparse warnings
cxl: Fix NULL dereference in cxl_context_init() on PowerVM guests
cxl: Use fixed width predefined types in data structure.
powerpc/vdso: Add missing include file
powerpc: Fix unused function warning 'lmb_to_memblock'
powerpc/powernv: Fix MCE handler to avoid trashing CR0/CR1 registers.
powerpc/powernv: Move IDLE_STATE_ENTER_SEQ macro to cpuidle.h
...
Kan Liang [Thu, 11 Aug 2016 14:31:14 +0000 (07:31 -0700)]
perf/x86/intel/uncore: Add enable_box for client MSR uncore
There are bug reports about miscounting uncore counters on some
client machines like Sandybridge, Broadwell and Skylake. It is
very likely to be observed on idle systems.
This issue is caused by a hardware issue. PERF_GLOBAL_CTL could be
cleared after Package C7, and nothing will be count.
The related errata (HSD 158) could be found in:
This patch tries to work around this issue by re-enabling PERF_GLOBAL_CTL
in ->enable_box(). The workaround does not cover all cases. It helps for new
events after returning from C7. But it cannot prevent C7, it will still
miscount if a counter is already active.
There is no drawback in leaving it enabled, so it does not need
disable_box() here.
Signed-off-by: Kan Liang <kan.liang@intel.com> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1470925874-59943-1-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Kan Liang [Thu, 11 Aug 2016 14:30:20 +0000 (07:30 -0700)]
perf/x86/intel/uncore: Fix uncore num_counters
Some uncore boxes' num_counters value for Haswell server and
Broadwell server are not correct (too large, off by one).
This issue was found by comparing the code with the document. Although
there is no bug report from users yet, accessing non-existent counters
is dangerous and the behavior is undefined: it may cause miscounting or
even crashes.
This patch makes them consistent with the uncore document.
Reported-by: Lukasz Odzioba <lukasz.odzioba@intel.com> Signed-off-by: Kan Liang <kan.liang@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1470925820-59847-1-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Denys Vlasenko [Thu, 11 Aug 2016 15:45:21 +0000 (17:45 +0200)]
uprobes/x86: Fix RIP-relative handling of EVEX-encoded instructions
Since instruction decoder now supports EVEX-encoded instructions, two fixes
are needed to correctly handle them in uprobes.
Extended bits for MODRM.rm field need to be sanitized just like we do it
for VEX3, to avoid encoding wrong register for register-relative access.
EVEX has _two_ extended bits: b and x. Theoretically, EVEX.x should be
ignored by the CPU (since GPRs go only up to 15, not 31), but let's be
paranoid here: proper encoding for register-relative access
should have EVEX.x = 1.
Secondly, we should fetch vex.vvvv for EVEX too.
This is now super easy because instruction decoder populates
vex_prefix.bytes[2] for all flavors of (e)vex encodings, even for VEX2.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: linux-kernel@vger.kernel.org Cc: <stable@vger.kernel.org> # v4.1+ Fixes: 8a764a875fe3 ("x86/asm/decoder: Create artificial 3rd byte for 2-byte VEX") Link: http://lkml.kernel.org/r/20160811154521.20469-1-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Linus Torvalds [Thu, 11 Aug 2016 23:58:24 +0000 (16:58 -0700)]
Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton:
"7 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm/memory_hotplug.c: initialize per_cpu_nodestats for hotadded pgdats
mm, oom: fix uninitialized ret in task_will_free_mem()
kasan: remove the unnecessary WARN_ONCE from quarantine.c
mm: memcontrol: fix memcg id ref counter on swap charge move
mm: memcontrol: fix swap counter leak on swapout from offline cgroup
proc, meminfo: use correct helpers for calculating LRU sizes in meminfo
mm/hugetlb: fix incorrect hugepages count during mem hotplug
kasan: remove the unnecessary WARN_ONCE from quarantine.c
It's quite unlikely that the user will so little memory that the per-CPU
quarantines won't fit into the given fraction of the available memory.
Even in that case he won't be able to do anything with the information
given in the warning.
Link: http://lkml.kernel.org/r/1470929182-101413-1-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vladimir Davydov [Thu, 11 Aug 2016 22:33:03 +0000 (15:33 -0700)]
mm: memcontrol: fix memcg id ref counter on swap charge move
Since commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure
after many small jobs") swap entries do not pin memcg->css.refcnt
directly. Instead, they pin memcg->id.ref. So we should adjust the
reference counters accordingly when moving swap charges between cgroups.
Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs") Link: http://lkml.kernel.org/r/9ce297c64954a42dc90b543bc76106c4a94f07e8.1470219853.git.vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [3.19+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vladimir Davydov [Thu, 11 Aug 2016 22:33:00 +0000 (15:33 -0700)]
mm: memcontrol: fix swap counter leak on swapout from offline cgroup
An offline memory cgroup might have anonymous memory or shmem left
charged to it and no swap. Since only swap entries pin the id of an
offline cgroup, such a cgroup will have no id and so an attempt to
swapout its anon/shmem will not store memory cgroup info in the swap
cgroup map. As a result, memcg->swap or memcg->memsw will never get
uncharged from it and any of its ascendants.
Fix this by always charging swapout to the first ancestor cgroup that
hasn't released its id yet.
[hannes@cmpxchg.org: add comment to mem_cgroup_swapout]
[vdavydov@virtuozzo.com: use WARN_ON_ONCE() in mem_cgroup_id_get_online()] Link: http://lkml.kernel.org/r/20160803123445.GJ13263@esperanza Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs") Link: http://lkml.kernel.org/r/5336daa5c9a32e776067773d9da655d2dc126491.1470219853.git.vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> [3.19+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 11 Aug 2016 22:32:57 +0000 (15:32 -0700)]
proc, meminfo: use correct helpers for calculating LRU sizes in meminfo
meminfo_proc_show() and si_mem_available() are using the wrong helpers
for calculating the size of the LRUs. The user-visible impact is that
there appears to be an abnormally high number of unevictable pages.
Link: http://lkml.kernel.org/r/20160805105805.GR2799@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
zhong jiang [Thu, 11 Aug 2016 22:32:55 +0000 (15:32 -0700)]
mm/hugetlb: fix incorrect hugepages count during mem hotplug
When memory hotplug operates, free hugepages will be freed if the
movable node is offline. Therefore, /proc/sys/vm/nr_hugepages will be
incorrect.
Fix it by reducing max_huge_pages when the node is offlined.
n-horiguchi@ah.jp.nec.com said:
: dissolve_free_huge_page intends to break a hugepage into buddy, and the
: destination hugepage is supposed to be allocated from the pool of the
: destination node, so the system-wide pool size is reduced. So adding
: h->max_huge_pages-- makes sense to me.
Linus Torvalds [Thu, 11 Aug 2016 21:14:23 +0000 (14:14 -0700)]
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Arnd Bergmann:
"A couple of bug fixes have come in for v4.8 so far. Since the first
few were originally meant to go into -rc1 (but didn't get sent in time
for travel reasons), the branch is unfortunately based on top of a
commit in the middle of the merge window rather than -rc1.
Content-wise we have:
- a fix for the last remaining broken build in kernelci, getting
mach-shmobile to build again with SMP disabled
- a fix for a realview regression that broke real hardware but not
the qemu model that everyone uses in practice (needed for v4.7 as
well)
- a merge conflict fix for Tegra that also broke v4.7
- two Kconfig fixes for arm64 build regressions
- a couple of arm32 build warning fixes (all harmless)
- fix the RTC on Exynos7 Espresso (which apparently never worked
right)"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
Merge tag 'pxa-fixes-v4.8' of https://github.com/rjarzmik/linux into randconfig-4.8
arm64: Kconfig: select HISILICON_IRQ_MBIGEN only if PCI is selected
arm64: Kconfig: select ALPINE_MSI only if PCI is selected
ARM: dts: realview: Fix PBX-A9 cache description
ARM: tegra: fix erroneous address in dts
ARM: dts: add syscon compatible string for AP syscon
ARM: dts: add syscon compatible string for CP syscon
ARM: oxnas: select reset controller framework
ARM: hide mach-*/ include for ARM_SINGLE_ARMV7M
ARM: don't include removed directories
Revert "ARM: aspeed: adapt defconfigs for new CONFIG_PRINTK_TIME"
ARM: shmobile: don't call platform_can_secondary_boot on UP
MAINTAINER: alpine: add a mailing list
ARM: do away with final ARCH_REQUIRE_GPIOLIB
arm64: dts: Fix RTC by providing rtc_src clock
Linus Torvalds [Thu, 11 Aug 2016 21:10:23 +0000 (14:10 -0700)]
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio/vhost fixes and cleanups from Michael Tsirkin:
"Misc fixes and cleanups all over the place"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
virtio/s390: deprecate old transport
virtio/s390: keep early_put_chars
virtio_blk: Fix a slient kernel panic
virtio-vsock: fix include guard typo
vhost/vsock: fix vhost virtio_vsock_pkt use-after-free
9p/trans_virtio: use kvfree() for iov_iter_get_pages_alloc()
virtio: fix error handling for debug builds
virtio: fix memory leak in virtqueue_add()
Linus Torvalds [Thu, 11 Aug 2016 20:53:34 +0000 (13:53 -0700)]
Merge tag 'ceph-for-4.8-rc2' of https://github.com/ceph/ceph-client
Pull ceph fixes from Ilya Dryomov:
"A patch for a NULL dereference bug introduced in 4.8-rc1 and a handful
of static checker fixes"
* tag 'ceph-for-4.8-rc2' of https://github.com/ceph/ceph-client:
ceph: initialize pathbase in the !dentry case in encode_caps_cb()
rbd: nuke the 32-bit pool id check
rbd: destroy header_oloc in rbd_dev_release()
ceph: fix null pointer dereference in ceph_flush_snaps()
libceph: using kfree_rcu() to simplify the code
libceph: make cancel_generic_request() static
libceph: fix return value check in alloc_msg_with_page_vector()
Chuck Lever [Thu, 11 Aug 2016 14:37:30 +0000 (10:37 -0400)]
nfsd: Fix race between FREE_STATEID and LOCK
When running LTP's nfslock01 test, the Linux client can send a LOCK
and a FREE_STATEID request at the same time. The outcome is:
Frame 324 R OPEN stateid [2,O]
Frame 115004 C LOCK lockowner_is_new stateid [2,O] offset 672000 len 64
Frame 115008 R LOCK stateid [1,L]
Frame 115012 C WRITE stateid [0,L] offset 672000 len 64
Frame 115016 R WRITE NFS4_OK
Frame 115019 C LOCKU stateid [1,L] offset 672000 len 64
Frame 115022 R LOCKU NFS4_OK
Frame 115025 C FREE_STATEID stateid [2,L]
Frame 115026 C LOCK lockowner_is_new stateid [2,O] offset 672128 len 64
Frame 115029 R FREE_STATEID NFS4_OK
Frame 115030 R LOCK stateid [3,L]
Frame 115034 C WRITE stateid [0,L] offset 672128 len 64
Frame 115038 R WRITE NFS4ERR_BAD_STATEID
In other words, the server returns stateid L in a successful LOCK
reply, but it has already released it. Subsequent uses of stateid L
fail.
To address this, protect the generation check in nfsd4_free_stateid
with the st_mutex. This should guarantee that only one of two
outcomes occurs: either LOCK returns a fresh valid stateid, or
FREE_STATEID returns NFS4ERR_LOCKS_HELD.
Reported-by: Alexey Kodanev <alexey.kodanev@oracle.com> Fix-suggested-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Alexey Kodanev <alexey.kodanev@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Josef Bacik [Wed, 10 Aug 2016 18:46:27 +0000 (14:46 -0400)]
nfsd: fix dentry refcounting on create
b44061d0b9 introduced a dentry ref counting bug. Previously we were
grabbing one ref to dchild in nfsd_create(), but with the creation of
nfsd_create_locked() we have a ref for dchild from the lookup in
nfsd_create(), and then another ref in nfsd_create_locked(). The ref
from the lookup in nfsd_create() is never dropped and results in
dentries still in use at unmount.
Signed-off-by: Josef Bacik <jbacik@fb.com> Fixes: b44061d0b9 "nfsd: reorganize nfsd_create" Reported-by: kernel test robot <xiaolong.ye@intel.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
x86/apic/x2apic, smp/hotplug: Don't use before alloc in x2apic_cluster_probe()
I made a mistake while converting the driver to the hotplug state
machine and as a result x2apic_cluster_probe() was accessing
cpus_in_cluster before allocating it.
This patch fixes it by setting the cpumask after the allocation the
memory succeeded.
While at it, I marked two functions static which are only used within
this file.
Reported-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 6b2c28471de5 ("x86/x2apic: Convert to CPU hotplug state machine") Link: http://lkml.kernel.org/r/1470924515-9444-1-git-send-email-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Austin Christ [Thu, 11 Aug 2016 10:42:00 +0000 (11:42 +0100)]
efi/capsule: Allocate whole capsule into virtual memory
According to UEFI 2.6 section 7.5.3, the capsule should be in contiguous
virtual memory and firmware may consume the capsule immediately. To
correctly implement this functionality, the kernel driver needs to vmap
the entire capsule at the time it is made available to firmware.
The virtual allocation of the capsule update has been changed from kmap,
which was only allocating the first page of the update, to vmap, and
allocates the entire data payload.
Signed-off-by: Austin Christ <austinwc@codeaurora.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Lee, Chun-Yi <jlee@suse.com> Cc: <stable@vger.kernel.org> # v4.7 Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kweh Hock Leong <hock.leong.kweh@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1470912120-22831-3-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
Alex Thorlton [Thu, 11 Aug 2016 10:41:59 +0000 (11:41 +0100)]
x86/platform/uv: Skip UV runtime services mapping in the efi_runtime_disabled case
This problem has actually been in the UV code for a while, but we didn't
catch it until recently, because we had been relying on EFI_OLD_MEMMAP
to allow our systems to boot for a period of time. We noticed the issue
when trying to kexec a recent community kernel, where we hit this NULL
pointer dereference in efi_sync_low_kernel_mappings():
[ 0.337515] BUG: unable to handle kernel NULL pointer dereference at 0000000000000880
[ 0.346276] IP: [<ffffffff8105df8d>] efi_sync_low_kernel_mappings+0x5d/0x1b0
The problem doesn't show up with EFI_OLD_MEMMAP because we skip the
chunk of setup_efi_state() that sets the efi_loader_signature for the
kexec'd kernel. When the kexec'd kernel boots, it won't set EFI_BOOT in
setup_arch, so we completely avoid the bug.
We always kexec with noefi on the command line, so this shouldn't be an
issue, but since we're not actually checking for efi_runtime_disabled in
uv_bios_init(), we end up trying to do EFI runtime callbacks when we
shouldn't be. This patch just adds a check for efi_runtime_disabled in
uv_bios_init() so that we don't map in uv_systab when runtime_disabled ==
true.
Signed-off-by: Alex Thorlton <athorlton@sgi.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: <stable@vger.kernel.org> # v4.7 Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Travis <travis@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1470912120-22831-2-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
My EBDA is at 0x2c000, which blocks off everything from 0x2c000 and
up, and my trampoline is 0x6000 bytes (6 pages), so it doesn't fit
in the loader data range at 0x28000.
Without this patch, it panics due to a failure to allocate the
trampoline. With this patch, it works:
[ +0.001744] Base memory trampoline at [ffff880000001000] 1000 size 24576
Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Matt Fleming <mfleming@suse.de> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/998c77b3bf709f3dfed85cb30701ed1a5d8a438b.1470821230.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andy Lutomirski [Wed, 10 Aug 2016 09:29:15 +0000 (02:29 -0700)]
x86/boot: Defer setup_real_mode() to early_initcall time
There's no need to run setup_real_mode() as early as we run it.
Defer it to the same early_initcall that sets up the page
permissions for the real mode code.
This should be a code size reduction. More importantly, it give us
a longer window in which we can allocate the real mode trampoline.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Matt Fleming <mfleming@suse.de> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/fd62f0da4f79357695e9bf3e365623736b05f119.1470821230.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andy Lutomirski [Wed, 10 Aug 2016 09:29:14 +0000 (02:29 -0700)]
x86/boot: Synchronize trampoline_cr4_features and mmu_cr4_features directly
The initialization process for trampoline_cr4_features and
mmu_cr4_features was confusing. The intent is for mmu_cr4_features
and *trampoline_cr4_features to stay in sync, but
trampoline_cr4_features is NULL until setup_real_mode() runs. The
old code synchronized *trampoline_cr4_features *twice*, once in
setup_real_mode() and once in setup_arch(). It also initialized
mmu_cr4_features in setup_real_mode(), which causes the actual value
of mmu_cr4_features to potentially depend on when setup_real_mode()
is called.
With this patch, mmu_cr4_features is initialized directly in
setup_arch(), and *trampoline_cr4_features is synchronized to
mmu_cr4_features when the trampoline is set up.
After this patch, it should be safe to defer setup_real_mode().
Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Matt Fleming <mfleming@suse.de> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/d48a263f9912389b957dd495a7127b009259ffe0.1470821230.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andy Lutomirski [Wed, 10 Aug 2016 09:29:13 +0000 (02:29 -0700)]
x86/boot: Run reserve_bios_regions() after we initialize the memory map
reserve_bios_regions() is a quirk that reserves memory that we might
otherwise think is available. There's no need to run it so early,
and running it before we have the memory map initialized with its
non-quirky inputs makes it hard to make reserve_bios_regions() more
intelligent.
Move it right after we populate the memblock state.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Matt Fleming <mfleming@suse.de> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/59f58618911005c799c6c9979ce6ae4881d907c2.1470821230.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Aaron Lu [Thu, 11 Aug 2016 07:44:30 +0000 (15:44 +0800)]
x86/irq: Do not substract irq_tlb_count from irq_call_count
Since commit:
52aec3308db8 ("x86/tlb: replace INVALIDATE_TLB_VECTOR by CALL_FUNCTION_VECTOR")
the TLB remote shootdown is done through call function vector. That
commit didn't take care of irq_tlb_count, which a later commit:
fd0f5869724f ("x86: Distinguish TLB shootdown interrupts from other functions call interrupts")
... tried to fix.
The fix assumes every increase of irq_tlb_count has a corresponding
increase of irq_call_count. So the irq_call_count is always bigger than
irq_tlb_count and we could substract irq_tlb_count from irq_call_count.
Unfortunately this is not true for the smp_call_function_single() case.
The IPI is only sent if the target CPU's call_single_queue is empty when
adding a csd into it in generic_exec_single. That means if two threads
are both adding flush tlb csds to the same CPU's call_single_queue, only
one IPI is sent. In other words, the irq_call_count is incremented by 1
but irq_tlb_count is incremented by 2. Over time, irq_tlb_count will be
bigger than irq_call_count and the substract will produce a very large
irq_call_count value due to overflow.
Considering that:
1) it's not worth to send more IPIs for the sake of accurate counting of
irq_call_count in generic_exec_single();
2) it's not easy to tell if the call function interrupt is for TLB
shootdown in __smp_call_function_single_interrupt().
Not to exclude TLB shootdown from call function count seems to be the
simplest fix and this patch just does that.
This bug was found by LKP's cyclic performance regression tracking recently
with the vm-scalability test suite. I have bisected to commit:
This commit didn't do anything wrong but revealed the irq_call_count
problem. IIUC, the commit makes rwc->remap_one in rmap_walk_file
concurrent with multiple threads. When remap_one is try_to_unmap_one(),
then multiple threads could queue flush TLB to the same CPU but only
one IPI will be sent.
Since the commit was added in Linux v3.19, the counting problem only
shows up from v3.19 onwards.
Signed-off-by: Aaron Lu <aaron.lu@intel.com> Cc: Alex Shi <alex.shi@linaro.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> Link: http://lkml.kernel.org/r/20160811074430.GA18163@aaronlu.sh.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Dave Hansen [Wed, 10 Aug 2016 17:23:25 +0000 (10:23 -0700)]
x86/mm: Fix swap entry comment and macro
A recent patch changed the format of a swap PTE.
The comment explaining the format of the swap PTE is wrong about
the bits used for the swap type field. Amusingly, the ASCII art
and the patch description are correct, but the comment itself
is wrong.
As I was looking at this, I also noticed that the
SWP_OFFSET_FIRST_BIT has an off-by-one error. This does not
really hurt anything. It just wasted a bit of space in the PTE,
giving us 2^59 bytes of addressable space in our swapfiles
instead of 2^60. But, it doesn't match with the comments, and it
wastes a bit of space, so fix it.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Fixes: 00839ee3b299 ("x86/mm: Move swap offset/type up in PTE to work around erratum") Link: http://lkml.kernel.org/r/20160810172325.E56AD7DA@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
... didn't take steal time into consideration with passing the noirqtime
kernel parameter.
As Paolo pointed out before:
| Why not? If idle=poll, for example, any time the guest is suspended (and
| thus cannot poll) does count as stolen time.
This patch fixes it by reducing steal time from idle time accounting when
the noirqtime parameter is true. The average idle time drops from 56.8%
to 54.75% for nohz idle kvm guest(noirqtime, idle=poll, four vCPUs running
on one pCPU).
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim <rkrcmar@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1470893795-3527-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Nicolas Iooss [Sat, 6 Aug 2016 10:20:39 +0000 (12:20 +0200)]
x86/mm/kaslr: Fix -Wformat-security warning
debug_putstr() is used to output strings without using printf-like
formatting but debug_putstr(v) is defined as early_printk(v) in
arch/x86/lib/kaslr.c.
This makes clang reports the following warning when building
with -Wformat-security:
arch/x86/lib/kaslr.c:57:15: warning: format string is not a string
literal (potentially insecure) [-Wformat-security]
debug_putstr(purpose);
^~~~~~~
Fix this by using "%s" in early_printk().
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160806102039.27221-1-nicolas.iooss_linux@m4x.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Linus Torvalds [Wed, 10 Aug 2016 23:41:09 +0000 (16:41 -0700)]
Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
"8 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm/slub.c: run free_partial() outside of the kmem_cache_node->list_lock
rmap: fix compound check logic in page_remove_file_rmap
mm, rmap: fix false positive VM_BUG() in page_add_file_rmap()
mm/page_alloc.c: recalculate some of node threshold when on/offline memory
mm/page_alloc.c: fix wrong initialization when sysctl_min_unmapped_ratio changes
thp: move shmem_huge_enabled() outside of SYSFS ifdef
revert "ARM: keystone: dts: add psci command definition"
rapidio: dereferencing an error pointer
Chris Wilson [Wed, 10 Aug 2016 23:27:58 +0000 (16:27 -0700)]
mm/slub.c: run free_partial() outside of the kmem_cache_node->list_lock
With debugobjects enabled and using SLAB_DESTROY_BY_RCU, when a
kmem_cache_node is destroyed the call_rcu() may trigger a slab
allocation to fill the debug object pool (__debug_object_init:fill_pool).
Everywhere but during kmem_cache_destroy(), discard_slab() is performed
outside of the kmem_cache_node->list_lock and avoids a lockdep warning
about potential recursion:
=============================================
[ INFO: possible recursive locking detected ]
4.8.0-rc1-gfxbench+ #1 Tainted: G U
---------------------------------------------
rmmod/8895 is trying to acquire lock:
(&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811c80d7>] get_partial_node.isra.63+0x47/0x430
but task is already holding lock:
(&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811cbda4>] __kmem_cache_shutdown+0x54/0x320
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(&n->list_lock)->rlock);
lock(&(&n->list_lock)->rlock);
*** DEADLOCK ***
May be due to missing lock nesting notation
5 locks held by rmmod/8895:
#0: (&dev->mutex){......}, at: driver_detach+0x42/0xc0
#1: (&dev->mutex){......}, at: driver_detach+0x50/0xc0
#2: (cpu_hotplug.dep_map){++++++}, at: get_online_cpus+0x2d/0x80
#3: (slab_mutex){+.+.+.}, at: kmem_cache_destroy+0x3c/0x220
#4: (&(&n->list_lock)->rlock){-.-...}, at: __kmem_cache_shutdown+0x54/0x320
Fixes: 52b4b950b507 ("mm: slab: free kmem_cache_node after destroy sysfs file") Link: http://lkml.kernel.org/r/1470759070-18743-1-git-send-email-chris@chris-wilson.co.uk Reported-by: Dave Gordon <david.s.gordon@intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: 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: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Gordon <david.s.gordon@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is meant to check for either HugeTLB pages or THP when a compound
page is passed in.
Unfortunately, if one disables CONFIG_TRANSPARENT_HUGEPAGE, then
PageTransHuge(.) will always return false, provoking BUGs when one runs
the libhugetlbfs test suite.
This patch replaces PageTransHuge(), with PageHead() which will work for
both HugeTLB and THP.
Fixes: dd78fedde4b9 ("rmap: support file thp") Link: http://lkml.kernel.org/r/1470838217-5889-1-git-send-email-steve.capper@arm.com Signed-off-by: Steve Capper <steve.capper@arm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Huang Shijie <shijie.huang@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm, rmap: fix false positive VM_BUG() in page_add_file_rmap()
PageTransCompound() doesn't distinguish THP from from any other type of
compound pages. This can lead to false-positive VM_BUG_ON() in
page_add_file_rmap() if called on compound page from a driver[1].
I think we can exclude such cases by checking if the page belong to a
mapping.
The VM_BUG_ON_PAGE() is downgraded to VM_WARN_ON_ONCE(). This path
should not cause any harm to non-THP page, but good to know if we step
on anything else.
Arnd Bergmann [Wed, 10 Aug 2016 23:27:44 +0000 (16:27 -0700)]
thp: move shmem_huge_enabled() outside of SYSFS ifdef
The newly introduced shmem_huge_enabled() function has two definitions,
but neither of them is visible if CONFIG_SYSFS is disabled, leading to a
build error:
mm/khugepaged.o: In function `khugepaged':
khugepaged.c:(.text.khugepaged+0x3ca): undefined reference to `shmem_huge_enabled'
This changes the #ifdef guards around the definition to match those that
are used in the header file.
Revert commit 51d5d12b8f3d ("ARM: keystone: dts: add psci command
definition"), which was inadvertently added twice.
Cc: Russell King - ARM Linux <linux@armlinux.org.uk> Cc: Vitaly Andrianov <vitalya@ti.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Carpenter [Wed, 10 Aug 2016 23:27:38 +0000 (16:27 -0700)]
rapidio: dereferencing an error pointer
Original patch: https://lkml.org/lkml/2016/8/4/32
If riocm_ch_alloc() fails then we end up dereferencing the error
pointer.
The problem is that we're not unwinding in the reverse order from how we
allocate things so it gets confusing. I've changed this around so now
"ch" is NULL when we are done with it after we call riocm_put_channel().
That way we can check if it's NULL and avoid calling riocm_put_channel()
on it twice.
I renamed err_nodev to err_put_new_ch so that it better reflects what
the goto does.
Then because we had flipping things around, it means we don't neeed to
initialize the pointers to NULL and we can remove an if statement and
pull things in an indent level.
Link: http://lkml.kernel.org/r/20160805152406.20713-1-alexandre.bounine@idt.com Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com> Cc: Barry Wood <barry.wood@idt.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Williams [Wed, 10 Aug 2016 22:59:09 +0000 (15:59 -0700)]
tools/testing/nvdimm: fix SIGTERM vs hotplug crash
The unit tests crash when hotplug races the previous probe. This race
requires that the loading of the nfit_test module be terminated with
SIGTERM, and the module to be unloaded while the ars scan is still
running.
In contrast to the normal nfit driver, the unit test calls
acpi_nfit_init() twice to simulate hotplug, whereas the nominal case
goes through the acpi_nfit_notify() event handler. The
acpi_nfit_notify() path is careful to flush the previous region
registration before servicing the hotplug event. The unit test was
missing this guarantee.
Robin Murphy [Wed, 10 Aug 2016 12:02:17 +0000 (14:02 +0200)]
ARM: dts: realview: Fix PBX-A9 cache description
Clearly QEMU is very permissive in how its PL310 model may be set up,
but the real hardware turns out to be far more particular about things
actually being correct. Fix up the DT description so that the real
thing actually boots:
- The arm,data-latency and arm,tag-latency properties need 3 cells to
be valid, otherwise we end up retaining the default 8-cycle latencies
which leads pretty quickly to lockup.
- The arm,dirty-latency property is only relevant to L210/L220, so get
rid of it.
- The cache geometry override also leads to lockup and/or general
misbehaviour. Irritatingly, the manual doesn't state the actual PL310
configuration, but based on the boardfile code and poking registers
from the Boot Monitor, it would seem to be 8 sets of 16KB ways.
With that, we can successfully boot to enjoy the fun of mismatched FPUs...
Cc: stable@vger.kernel.org Signed-off-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
c90bb7b enabled the high speed UARTs of the Jetson TK1. Due to a merge
quirk, wrong addresses were introduced. Fix it and use the correct
addresses.
Thierry let me know, that there is another patch (b5896f67ab3c in
linux-next) in preparation which removes all the '0,' prefixes of unit
addresses on Tegra124 and is planned to go upstream in 4.8, so
this patch will get reverted then.
But for the moment, this patch is necessary to fix current misbehaviour.
Arnd Bergmann [Thu, 9 Jun 2016 07:50:28 +0000 (09:50 +0200)]
ARM: hide mach-*/ include for ARM_SINGLE_ARMV7M
The machine specific header files are exported for traditional
platforms, but not for the ones that use ARCH_MULTIPLATFORM, as
they could conflict with one another.
In case of ARM_SINGLE_ARMV7M, we end up also exporting them,
but that appears to be a mistake, and we should treat it the
same way as ARCH_MULTIPLATFORM here.
'make W=1' warns about this because it passes -Wmissing-includes
to gcc and the directories are not actually present.
Arnd Bergmann [Wed, 8 Jun 2016 14:21:19 +0000 (16:21 +0200)]
ARM: don't include removed directories
Three platforms used to have header files in include/mach that
are now all gone, but the removed directories are still being
included, which leads to -Wmissing-include-dirs warnings.
Linus Torvalds [Wed, 10 Aug 2016 18:16:03 +0000 (11:16 -0700)]
Merge branch 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"Some fixes for btrfs send/recv and fsync from Filipe and Robbie Ko.
Bonus points to Filipe for already having xfstests in place for many
of these"
* 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: remove unused function btrfs_add_delayed_qgroup_reserve()
Btrfs: improve performance on fsync against new inode after rename/unlink
Btrfs: be more precise on errors when getting an inode from disk
Btrfs: send, don't bug on inconsistent snapshots
Btrfs: send, avoid incorrect leaf accesses when sending utimes operations
Btrfs: send, fix invalid leaf accesses due to incorrect utimes operations
Btrfs: send, fix warning due to late freeing of orphan_dir_info structures
Btrfs: incremental send, fix premature rmdir operations
Btrfs: incremental send, fix invalid paths for rename operations
Btrfs: send, add missing error check for calls to path_loop()
Btrfs: send, fix failure to move directories with the same name around
Btrfs: add missing check for writeback errors on fsync
Linus Torvalds [Wed, 10 Aug 2016 18:07:47 +0000 (11:07 -0700)]
Merge tag 'metag-for-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag
Pull metag architecture fix from James Hogan:
"A single fix for a boot crash since a commit in the merge window.
Metag was unusual in calling show_mem() early, before setup_per_cpu_pageset(),
which is no longer safe. It doesn't add much value to the log, so the
fix just drops the call"
* tag 'metag-for-v4.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
metag: Drop show_mem() from mem_init()
The Memory Protection Keys "rights register" (PKRU) is
XSAVE-managed, and is saved/restored along with the FPU state.
When kernel code accesses FPU regsisters, it does a delicate
dance with preempt. Otherwise, the context switching code can
get confused as to whether the most up-to-date state is in the
registers themselves or in the XSAVE buffer.
But, PKRU is not a normal FPU register. Using it does not
generate the normal device-not-available (#NM) exceptions which
means we can not manage it lazily, and the kernel completley
disallows using lazy mode when it is enabled.
The dance with preempt *only* occurs when managing the FPU
lazily. Since we never manage PKRU lazily, we do not have to do
the dance with preempt; we can access it directly. Doing it
this way saves a ton of complicated code (and is faster too).
Further, the XSAVES reenabling failed to patch a bit of code
in fpu__xfeature_set_state() the checked for compacted buffers.
That check caused fpu__xfeature_set_state() to silently refuse to
work when the kernel is using compacted XSAVE buffers. This
broke execute-only and future pkey_mprotect() support when using
compact XSAVE buffers.
But, removing fpu__xfeature_set_state() gets rid of this issue,
in addition to the nice cleanup and speedup.
This fixes the same thing as a fix that Sai posted:
https://lkml.org/lkml/2016/7/25/637
The fix that he posted is a much more obviously correct, but I
think we should just do this instead.
Reported-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave@sr71.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-Cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20160727232040.7D060DAD@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86/build: Reduce the W=1 warnings noise when compiling x86 syscall tables
Building an X86_64 kernel with W=1 throws a total of 9,948 lines of warnings of
this form for both 32-bit and 64-bit syscall tables. Given that the entire rest
of the build for my config only generates 8,375 lines of output, this is a big
reduction in the warnings generated.
The warnings follow this pattern:
./arch/x86/include/generated/asm/syscalls_32.h:885:21: warning: initialized field overwritten [-Woverride-init]
__SYSCALL_I386(379, compat_sys_pwritev2, )
^
arch/x86/entry/syscall_32.c:13:46: note: in definition of macro '__SYSCALL_I386'
#define __SYSCALL_I386(nr, sym, qual) [nr] = sym,
^~~
./arch/x86/include/generated/asm/syscalls_32.h:885:21: note: (near initialization for 'ia32_sys_call_table[379]')
__SYSCALL_I386(379, compat_sys_pwritev2, )
^
arch/x86/entry/syscall_32.c:13:46: note: in definition of macro '__SYSCALL_I386'
#define __SYSCALL_I386(nr, sym, qual) [nr] = sym,
Since we intentionally build the syscall tables this way, ignore that one
warning in the two files.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/7464.1470021890@turing-police.cc.vt.edu Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mike Travis [Mon, 1 Aug 2016 18:40:53 +0000 (13:40 -0500)]
x86/platform/UV: Fix kernel panic running RHEL kdump kernel on UV systems
The latest UV kernel support panics when RHEL7 kexec's the kdump kernel
to make a dumpfile. This patch fixes the problem by turning off all UV
support if NUMA is off.
Tested-by: Frank Ramsay <framsay@sgi.com> Tested-by: John Estabrook <estabrook@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Dimitri Sivanich <sivanich@sgi.com> Reviewed-by: Nathan Zimmer <nzimmer@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160801184050.577755634@asylum.americas.sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mike Travis [Mon, 1 Aug 2016 18:40:52 +0000 (13:40 -0500)]
x86/platform/UV: Fix problem with UV4 BIOS providing incorrect PXM values
There are some circumstances where the UV4 BIOS cannot provide the
correct Proximity Node values to associate with specific Sockets and
Physical Nodes. The decision was made to remove these values from BIOS
and for the kernel to get these values from the standard ACPI tables.
Tested-by: Frank Ramsay <framsay@sgi.com> Tested-by: John Estabrook <estabrook@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Dimitri Sivanich <sivanich@sgi.com> Reviewed-by: Nathan Zimmer <nzimmer@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160801184050.414210079@asylum.americas.sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mike Travis [Mon, 1 Aug 2016 18:40:50 +0000 (13:40 -0500)]
x86/platform/UV: Fix problem with UV4 Socket IDs not being contiguous
The UV4 Socket IDs are not guaranteed to equate to Node values which
can cause the GAM (Global Addressable Memory) table lookups to fail.
Fix this by using an independent index into the GAM table instead of
the Socket ID to reference the base address.
Tested-by: Frank Ramsay <framsay@sgi.com> Tested-by: John Estabrook <estabrook@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Dimitri Sivanich <sivanich@sgi.com> Reviewed-by: Nathan Zimmer <nzimmer@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Andrew Banman <abanman@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160801184050.048755337@asylum.americas.sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Usually current->mm (and therefore mm->pgd) stays the same during the
lifetime of a task so it does not matter if a task gets preempted during
the read and write of the CR3.
But then, there is this scenario on x86-UP:
TaskA is in do_exit() and exit_mm() sets current->mm = NULL followed by:
At this point current->mm is NULL but current->active_mm still points to
the "old" mm.
Let's preempt taskA _after_ native_read_cr3() by taskB. TaskB has its
own mm so CR3 has changed.
Now preempt back to taskA. TaskA has no ->mm set so it borrows taskB's
mm and so CR3 remains unchanged. Once taskA gets active it continues
where it was interrupted and that means it writes its old CR3 value
back. Everything is fine because userland won't need its memory
anymore.
Now the fun part:
Let's preempt taskA one more time and get back to taskB. This
time switch_mm() won't do a thing because oldmm (->active_mm)
is the same as mm (as per context_switch()). So we remain
with a bad CR3 / PGD and return to userland.
The next thing that happens is handle_mm_fault() with an address for
the execution of its code in userland. handle_mm_fault() realizes that
it has a PTE with proper rights so it returns doing nothing. But the
CPU looks at the wrong PGD and insists that something is wrong and
faults again. And again. And one more time…
This pagefault circle continues until the scheduler gets tired of it and
puts another task on the CPU. It gets little difficult if the task is a
RT task with a high priority. The system will either freeze or it gets
fixed by the software watchdog thread which usually runs at RT-max prio.
But waiting for the watchdog will increase the latency of the RT task
which is no good.
Fix this by disabling preemption across the critical code section.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1470404259-26290-1-git-send-email-bigeasy@linutronix.de
[ Prettified the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Takashi Iwai [Thu, 4 Aug 2016 20:38:36 +0000 (22:38 +0200)]
ALSA: hda - Manage power well properly for resume
For SKL and later Intel chips, we control the power well per codec
basis via link_power callback since the commit [03b135cebc47: ALSA:
hda - remove dependency on i915 power well for SKL].
However, there are a few exceptional cases where the gfx registers are
accessed from the audio driver: namely the wakeup override bit
toggling at (both system and runtime) resume. This seems causing a
kernel warning when accessed during the power well down (and likely
resulting in the bogus register accesses).
This patch puts the proper power up / down sequence around the resume
code so that the wakeup bit is fiddled properly while the power is
up. (The other callback, sync_audio_rate, is used only in the PCM
callback, so it's guaranteed in the power-on.)
Also, by this proper power up/down, the instantaneous flip of wakeup
bit in the resume callback that was introduced by the commit
[033ea349a7cd: ALSA: hda - Fix Skylake codec timeout] becomes
superfluous, as snd_hdac_display_power() already does it. So we can
clean it up together.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96214 Fixes: 03b135cebc47 ('ALSA: hda - remove dependency on i915 power well for SKL') Cc: <stable@vger.kernel.org> # v4.2+ Tested-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Nicholas Piggin [Tue, 9 Aug 2016 12:17:29 +0000 (22:17 +1000)]
powerpc/vdso: Fix build rules to rebuild vdsos correctly
When using if_changed, we need to add FORCE as a dependency (see
Documentation/kbuild/makefiles.txt) otherwise we don't get command line
change checking amongst other things. This has resulted in vdsos not
being rebuilt when switching between big and little endian.
The vdso64/32ld commands have to be changed around to avoid pulling
FORCE into the linker command line (code copied from x86).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/Makefile: Use cflags-y/aflags-y for setting endian options
When we introduced the little endian support, we added the endian flags
to CC directly using override. I don't know the history of why we did
that, I suspect no one does.
Although this mostly works, it has one bug, which is that CROSS32CC
doesn't get -mbig-endian. That means when the compiler is little endian
by default and the user is building big endian, vdso32 is incorrectly
compiled as little endian and the kernel fails to build.
Instead we can add the endian flags to cflags-y/aflags-y, and then
append those to KBUILD_CFLAGS/KBUILD_AFLAGS.
This has the advantage of being 1) less ugly, 2) the documented way of
adding flags in the arch Makefile and 3) it fixes building vdso32 with a
LE toolchain.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Thomas Garnier [Tue, 9 Aug 2016 17:11:05 +0000 (10:11 -0700)]
x86/mm/KASLR: Increase BRK pages for KASLR memory randomization
Default implementation expects 6 pages maximum are needed for low page
allocations. If KASLR memory randomization is enabled, the worse case
of e820 layout would require 12 pages (no large pages). It is due to the
PUD level randomization and the variable e820 memory layout.
This bug was found while doing extensive testing of KASLR memory
randomization on different type of hardware.
Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Aleksey Makarov <aleksey.makarov@linaro.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lv Zheng <lv.zheng@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: kernel-hardening@lists.openwall.com Fixes: 021182e52fe0 ("Enable KASLR for physical mapping memory regions") Link: http://lkml.kernel.org/r/1470762665-88032-2-git-send-email-thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Thomas Garnier [Tue, 9 Aug 2016 17:11:04 +0000 (10:11 -0700)]
x86/mm/KASLR: Fix physical memory calculation on KASLR memory randomization
Initialize KASLR memory randomization after max_pfn is initialized. Also
ensure the size is rounded up. It could create problems on machines
with more than 1Tb of memory on certain random addresses.
Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Aleksey Makarov <aleksey.makarov@linaro.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lv Zheng <lv.zheng@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: kernel-hardening@lists.openwall.com Fixes: 021182e52fe0 ("Enable KASLR for physical mapping memory regions") Link: http://lkml.kernel.org/r/1470762665-88032-1-git-send-email-thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
This was caused by a stupid typo in a patch that should have been
a simple rename to move around contents of a header file, but
accidentally wrote zeroes into the rtc rather than reading from
it:
463a86304cae ("char/genrtc: x86: remove remnants of asm/rtc.h")
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Borislav Petkov <bp@suse.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: rtc-linux@googlegroups.com Fixes: 463a86304cae ("char/genrtc: x86: remove remnants of asm/rtc.h") Link: http://lkml.kernel.org/r/20160809195528.1604312-1-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text
Dmitry Vyukov has reported unexpected KASAN stackdepot growth:
https://github.com/google/kasan/issues/36
... which is caused by the APIC handlers not being present in .irqentry.text:
When building with CONFIG_FUNCTION_GRAPH_TRACER=y or CONFIG_KASAN=y, put the
APIC interrupt handlers into the .irqentry.text section. This is needed
because both KASAN and function graph tracer use __irqentry_text_start and
__irqentry_text_end to determine whether a function is an IRQ entry point.
Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: aryabinin@virtuozzo.com Cc: kasan-dev@googlegroups.com Cc: kcc@google.com Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/1468575763-144889-1-git-send-email-glider@google.com
[ Minor edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pan Xinhui [Wed, 13 Jul 2016 10:23:34 +0000 (18:23 +0800)]
locking/pvqspinlock: Fix a bug in qstat_read()
It's obviously wrong to set stat to NULL. So lets remove it.
Otherwise it is always zero when we check the latency of kick/wake.
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Waiman Long <Waiman.Long@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468405414-3700-1-git-send-email-xinhui.pan@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
In this case, lock holder inserts the pv_node of queue head into the
hash table and set _Q_SLOW_VAL unnecessary. This patch avoids it by
restoring/setting vcpu_hashed state after failing adaptive locking
spinning.
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <Waiman.Long@hpe.com> Link: http://lkml.kernel.org/r/1468484156-4521-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
pan xinhui [Mon, 18 Jul 2016 09:47:39 +0000 (17:47 +0800)]
locking/qrwlock: Fix write unlock bug on big endian systems
This patch aims to get rid of endianness in queued_write_unlock(). We
want to set __qrwlock->wmode to NULL, however the address is not
&lock->cnts in big endian machine. That causes queued_write_unlock()
write NULL to the wrong field of __qrwlock.
So implement __qrwlock_write_byte() which returns the correct
__qrwlock->wmode address.
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman.Long@hpe.com Cc: arnd@arndb.de Cc: boqun.feng@gmail.com Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1468835259-4486-1-git-send-email-xinhui.pan@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
fixed a problem whereby clock_nanosleep() followed by clock_gettime() could
allow a task to wake early. It addressed the problem by calling the scheduling
classes update_curr() when the cputimer starts.
Said change induced a considerable performance regression on the syscalls
times() and clock_gettimes(CLOCK_PROCESS_CPUTIME_ID). There are some
debuggers and applications that monitor their own performance that
accidentally depend on the performance of these specific calls.
This patch mitigates the performace loss by prefetching data in the CPU
cache, as stalls due to cache misses appear to be where most time is spent
in our benchmarks.
Here are the performance gain of this patch over v4.7-rc7 on a Sandy Bridge
box with 32 logical cores and 2 NUMA nodes. The test is repeated with a
variable number of threads, from 2 to 4*num_cpus; the results are in
seconds and correspond to the average of 10 runs; the percentage gain is
computed with (before-after)/before so a positive value is an improvement
(it's faster). The improvement varies between a few percents for 5-20
threads and more than 10% for 2 or >20 threads.
pound_clock_gettime and pound_clock_gettime are two benchmarks included in
the MMTests framework. They launch a given number of threads which
repeatedly call times() or clock_gettimes(). The results above can be
reproduced with cloning MMTests from github.com and running the "poundtime"
workload:
The above will run "poundtime" measuring the kernel currently running on
the machine; Once a new kernel is installed and the machine rebooted,
running again
$ cd mmtests
$ ./run-mmtests.sh --run-monitor $(uname -r)
will produce results to compare with. A comparison table will be output
with:
$ cd mmtests/work/log
$ ../../compare-kernels.sh
the table will contain a lot of entries; grepping for "Amean" (as in
"arithmetic mean") will give the tables presented above. The source code
for the two benchmarks is reported at the end of this changelog for
clairity.
The cache misses addressed by this patch were found using a combination of
`perf top`, `perf record` and `perf annotate`. The incriminated lines were
found to be
struct sched_entity *curr = cfs_rq->curr;
and
delta_exec = now - curr->exec_start;
in the function update_curr() from kernel/sched/fair.c. This patch
prefetches the data from memory just before update_curr is called in the
interested execution path.
A comparison of the total number of cycles before and after the patch
follows; the data is obtained using `perf stat -r 10 -ddd <program>`
running over the same sequence of number of threads used above (a positive
gain is an improvement):
As a final note, the following shows the evolution of performance figures
in the "poundtime" benchmark and pinpoints commit 6e998916dfe3
("sched/cputime: Fix clock_nanosleep()/clock_gettime() inconsistency") as a
major source of degradation, mostly unaddressed to this day (figures
expressed in seconds).
Current code in cpudeadline.c has a bug in re-heapifying when adding a
new element at the end of the heap, because a deadline value of 0 is
temporarily set in the new elem, then cpudl_change_key() is called
with the actual elem deadline as param.
However, the function compares the new deadline to set with the one
previously in the elem, which is 0. So, if current absolute deadlines
grew so much to have negative values as s64, the comparison in
cpudl_change_key() makes the wrong decision. Instead, as from
dl_time_before(), the kernel should handle correctly abs deadlines
wrap-arounds.
This patch fixes the problem with a minimally invasive change that
forces cpudl_change_key() to heapify up in this case.
Signed-off-by: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Luca Abeni <luca.abeni@unitn.it> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468921493-10054-2-git-send-email-tommaso.cucinotta@sssup.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
The underlying problem is that there is an optimization in
perf_cgroup_sched_{in,out}() that skips the switch of cgroup events
if the old and new cgroups in a task switch are the same.
This optimization interacts with the current code in two ways
that cause a CPU context's cgroup (cpuctx->cgrp) to be NULL even if a
cgroup event matches the current task. These are:
1. On creation of the first cgroup event in a CPU: In current code,
cpuctx->cpu is only set in perf_cgroup_sched_in, but due to the
aforesaid optimization, perf_cgroup_sched_in will run until the next
cgroup switches in that CPU. This may happen late or never happen,
depending on system's number of cgroups, CPU load, etc.
2. On deletion of the last cgroup event in a cpuctx: In list_del_event,
cpuctx->cgrp is set NULL. Any new cgroup event will not be sched in
because cpuctx->cgrp == NULL until a cgroup switch occurs and
perf_cgroup_sched_in is executed (updating cpuctx->cgrp).
This patch fixes both problems by setting cpuctx->cgrp in list_add_event,
mirroring what list_del_event does when removing a cgroup event from CPU
context, as introduced in:
commit 68cacd29167b ("perf_events: Fix stale ->cgrp pointer in update_cgrp_time_from_cpuctx()")
With this patch, cpuctx->cgrp is always set/clear when installing/removing
the first/last cgroup event in/from the CPU context. With cpuctx->cgrp
correctly set, event_filter_match works as intended when events are
sched in/out.
Vegard Nossum reported that perf fuzzing generates a NULL
pointer dereference crash:
> Digging a bit deeper into this, it seems the event itself is getting
> created by perf_event_open() and it gets added to the pmu_event_list
> through:
>
> perf_event_open()
> - perf_event_alloc()
> - account_event()
> - account_pmu_sb_event()
> - attach_sb_event()
>
> so at this point the event is being attached but its ->ctx is still
> NULL. It seems like ->ctx is set just a bit later in
> perf_event_open(), though.
>
> But before that, __schedule() comes along and creates a stack trace
> similar to the one above:
>
> __schedule()
> - __perf_event_task_sched_out()
> - perf_iterate_sb()
> - perf_iterate_sb_cpu()
> - event_filter_match()
> - perf_cgroup_match()
> - __get_cpu_context()
> - (dereference ctx which is NULL)
>
> So I guess the question is... should the event be attached (= put on
> the list) before ->ctx gets set? Or should the cgroup code check for a
> NULL ->ctx?
The latter seems like the simplest solution. Moving the list-add later
creates a bit of a mess.
Reported-by: Vegard Nossum <vegard.nossum@gmail.com> Tested-by: Vegard Nossum <vegard.nossum@gmail.com> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Carrillo-Cisneros <davidcc@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: f2fb6bef9251 ("perf/core: Optimize side-band event delivery") Link: http://lkml.kernel.org/r/20160804123724.GN6862@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86/timers/apic: Inform TSC deadline clockevent device about recalibration
This patch eliminates a source of imprecise APIC timer interrupts,
which imprecision may result in double interrupts or even late
interrupts.
The TSC deadline clockevent devices' configuration and registration
happens before the TSC frequency calibration is refined in
tsc_refine_calibration_work().
This results in the TSC clocksource and the TSC deadline clockevent
devices being configured with slightly different frequencies: the former
gets the refined one and the latter are configured with the inaccurate
frequency detected earlier by means of the "Fast TSC calibration using PIT".
Within the APIC code, introduce the notifier function
lapic_update_tsc_freq() which reconfigures all per-CPU TSC deadline
clockevent devices with the current tsc_khz.
Call it from the TSC code after TSC calibration refinement has happened.
Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Christopher S. Hall <christopher.s.hall@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/20160714152255.18295-3-nicstange@gmail.com
[ Pushed #ifdef CONFIG_X86_LOCAL_APIC into header, improved changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86/timers/apic: Fix imprecise timer interrupts by eliminating TSC clockevents frequency roundoff error
I noticed the following bug/misbehavior on certain Intel systems: with a
single task running on a NOHZ CPU on an Intel Haswell, I recognized
that I did not only get the one expected local_timer APIC interrupt, but
two per second at minimum. (!)
Further tracing showed that the first one precedes the programmed deadline
by up to ~50us and hence, it did nothing except for reprogramming the TSC
deadline clockevent device to trigger shortly thereafter again.
The reason for this is imprecise calibration, the timeout we program into
the APIC results in 'too short' timer interrupts. The core (hr)timer code
notices this (because it has a precise ktime source and sees the short
interrupt) and fixes it up by programming an additional very short
interrupt period.
This is obviously suboptimal.
The reason for the imprecise calibration is twofold, and this patch
fixes the first reason:
In setup_APIC_timer(), the registered clockevent device's frequency
is calculated by first dividing tsc_khz by TSC_DIVISOR and multiplying
it with 1000 afterwards:
(tsc_khz / TSC_DIVISOR) * 1000
The multiplication with 1000 is done for converting from kHz to Hz and the
division by TSC_DIVISOR is carried out in order to make sure that the final
result fits into an u32.
However, with the order given in this calculation, the roundoff error
introduced by the division gets magnified by a factor of 1000 by the
following multiplication.
To fix it, reversing the order of the division and the multiplication a la:
(tsc_khz * 1000) / TSC_DIVISOR
... reduces the roundoff error already.
Furthermore, if TSC_DIVISOR divides 1000, associativity holds:
and thus, the roundoff error even vanishes and the whole operation can be
carried out within 32 bits.
The powers of two that divide 1000 are 2, 4 and 8. A value of 8 for
TSC_DIVISOR still allows for TSC frequencies up to
2^32 / 10^9ns * 8 = 34.4GHz which is way larger than anything to expect
in the next years.
Thus we also replace the current TSC_DIVISOR value of 32 by 8. Reverse
the order of the divison and the multiplication in the calculation of
the registered clockevent device's frequency.
Signed-off-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Christopher S. Hall <christopher.s.hall@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Link: http://lkml.kernel.org/r/20160714152255.18295-2-nicstange@gmail.com
[ Improved changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
projects / mirror_ubuntu-kernels.git / log