HID: core: allow concurrent registration of drivers
Detected on the Dell XPS 9365.
The laptop has 2 devices that benefit from the hid-generic auto-unbinding.
When those 2 devices are presented to the userspace, udev loads both wacom and
hid-multitouch. When this happens, the code in __hid_bus_reprobe_drivers() is
called concurrently and the second device gets reprobed twice.
An other bug in the power_supply subsystem prevent to remove the wacom driver
if it just finished its initialization, which basically kills the wacom node.
[jkosina@suse.cz: reformat changelog a bit]
Fixes c17a7476e4c4 ("HID: core: rewrite the hid-generic automatic unbind") Cc: stable@vger.kernel.org # v4.17 Tested-by: Mario Limonciello <mario.limonciello@dell.com> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Jason Gerecke [Tue, 12 Jun 2018 20:42:46 +0000 (13:42 -0700)]
HID: wacom: Correct logical maximum Y for 2nd-gen Intuos Pro large
The HID descriptor for the 2nd-gen Intuos Pro large (PTH-860) contains
a typo which defines an incorrect logical maximum Y value. This causes
a small portion of the bottom of the tablet to become unusable (both
because the area is below the "bottom" of the tablet and because
'wacom_wac_event' ignores out-of-range values). It also results in a
skewed aspect ratio.
To fix this, we add a quirk to 'wacom_usage_mapping' which overwrites
the data with the correct value.
Even Xu [Thu, 11 Feb 2016 20:11:34 +0000 (04:11 +0800)]
HID: intel_ish-hid: ipc: register more pm callbacks to support hibernation
Current ISH driver only registers suspend/resume PM callbacks which don't
support hibernation (suspend to disk). Basically after hiberation, the ISH
can't resume properly and user may not see sensor events (for example: screen
rotation may not work).
User will not see a crash or panic or anything except the following message
in log:
hid-sensor-hub 001F:8086:22D8.0001: timeout waiting for response from ISHTP device
So this patch adds support for S4/hiberbation to ISH by using the
SIMPLE_DEV_PM_OPS() MACRO instead of struct dev_pm_ops directly. The suspend
and resume functions will now be used for both suspend to RAM and hibernation.
If power management is disabled, SIMPLE_DEV_PM_OPS will do nothing, the suspend
and resume related functions won't be used, so mark them as __maybe_unused to
clarify that this is the intended behavior, and remove #ifdefs for power
management.
HID: steam: use hid_device.driver_data instead of hid_set_drvdata()
When creating the low-level hidraw device, the reference to steam_device
was stored using hid_set_drvdata(). But this value is not guaranteed to
be kept when set before calling probe. If this pointer is reset, it
crashes when opening the emulated hidraw device.
It looks like hid_set_drvdata() is for users "avobe" this hid_device,
while hid_device.driver_data it for users "below" this one.
In this case, we are creating a virtual hidraw device, so we must use
hid_device.driver_data.
Linus Torvalds [Fri, 8 Jun 2018 17:29:26 +0000 (10:29 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Pull HID updates from Jiri Kosina:
- Valve Steam Controller support from Rodrigo Rivas Costa
- Redragon Asura support from Robert Munteanu
- improvement of duplicate usage handling in generic hid-input from
Benjamin Tissoires
- Win 8.1 precisioun touchpad spec implementation from Benjamin
Tissoires
- Support for "In Range" flag for Wacom Intuos/Bamboo devices from
Jason Gerecke
- other various assorted smaller fixes and improvements
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (27 commits)
HID: rmi: use HID_QUIRK_NO_INPUT_SYNC
HID: multitouch: fix calculation of last slot field in multi-touch reports
HID: quirks: remove Delcom Visual Signal Indicator from hid_have_special_driver[]
HID: steam: select CONFIG_POWER_SUPPLY
HID: i2c-hid: remove i2c_hid_open_mut
HID: wacom: Support "in range" for Intuos/Bamboo tablets where possible
HID: core: fix hid_hw_open() comment
HID: hid-plantronics: Re-resend Update to map button for PTT products
HID: multitouch: fix types returned from mt_need_to_apply_feature()
HID: i2c-hid: check if device is there before really probing
HID: steam: add missing fields in client initialization
HID: steam: add battery device.
HID: add driver for Valve Steam Controller
HID: alps: Fix some style in 't4_read_write_register()'
HID: alps: Check errors returned by 't4_read_write_register()'
HID: alps: Save a memory allocation in 't4_read_write_register()' when writing data
HID: alps: Report an error if we receive invalid data in 't4_read_write_register()'
HID: multitouch: implement precision touchpad latency and switches
HID: multitouch: simplify the settings of the various features
HID: multitouch: make use of HID_QUIRK_INPUT_PER_APP
...
Linus Torvalds [Fri, 8 Jun 2018 17:27:41 +0000 (10:27 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching fixlet from Jiri Kosina:
"livepatching documentation fix from Petr Mladek"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
livepatch: Remove not longer valid limitations from the documentation
Linus Torvalds [Fri, 8 Jun 2018 17:00:20 +0000 (10:00 -0700)]
Merge branch 'work.aio' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull aio iopriority support from Al Viro:
"The rest of aio stuff for this cycle - Adam's aio ioprio series"
* 'work.aio' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: aio ioprio use ioprio_check_cap ret val
fs: aio ioprio add explicit block layer dependence
fs: iomap dio set bio prio from kiocb prio
fs: blkdev set bio prio from kiocb prio
fs: Add aio iopriority support
fs: Convert kiocb rw_hint from enum to u16
block: add ioprio_check_cap function
Linus Torvalds [Fri, 8 Jun 2018 16:56:38 +0000 (09:56 -0700)]
Merge branch 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull proc_fill_cache regression fix from Al Viro:
"Regression fix for proc_fill_cache() braino introduced when switching
instantiate() callback to d_splice_alias()"
* 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fix proc_fill_cache() in case of d_alloc_parallel() failure
Linus Torvalds [Fri, 8 Jun 2018 16:24:54 +0000 (09:24 -0700)]
Merge tag 'for-linus-4.18-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross:
"This contains some minor code cleanups (fixing return types of
functions), some fixes for Linux running as Xen PVH guest, and adding
of a new guest resource mapping feature for Xen tools"
* tag 'for-linus-4.18-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/PVH: Make GDT selectors PVH-specific
xen/PVH: Set up GS segment for stack canary
xen/store: do not store local values in xen_start_info
xen-netfront: fix xennet_start_xmit()'s return type
xen/privcmd: add IOCTL_PRIVCMD_MMAP_RESOURCE
xen: Change return type to vm_fault_t
Jiri Kosina [Fri, 8 Jun 2018 08:25:50 +0000 (10:25 +0200)]
Merge branch 'for-4.18/multitouch' into for-linus
- improvement of duplicate usage handling in hid-input from Benjamin Tissoires
- Win 8.1 precisioun touchpad spec implementation from Benjamin Tissoires
Al Viro [Fri, 8 Jun 2018 05:17:11 +0000 (01:17 -0400)]
fix proc_fill_cache() in case of d_alloc_parallel() failure
If d_alloc_parallel() returns ERR_PTR(...), we don't want to dput()
that. Small reorganization allows to have all error-in-lookup
cases rejoin the main codepath after dput(child), avoiding the
entire problem.
Spotted-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Fixes: 0168b9e38c42 "procfs: switch instantiate_t to d_splice_alias()" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Dan Carpenter [Fri, 8 Jun 2018 00:11:52 +0000 (17:11 -0700)]
autofs: small cleanup in autofs_getpath()
We don't set "*name" so it's slightly nicer to just pass "name" instead
of "&name".
Link: http://lkml.kernel.org/r/20180531064736.lnisb55eajwjynvk@kili.mountain Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ian Kent [Fri, 8 Jun 2018 00:11:45 +0000 (17:11 -0700)]
autofs: comment on selinux changes needed for module autoload
Due to the autofs4 module using a file system type name of autofs
different from the module containing directory name autoload did not
function properly. To work around this kernel configurations have often
elected to build the module into the kernel.
This can result in selinux policies that prohibit autoloading of the
autofs module which need to be changed.
Add a comment about this to "possible changes" section of the autofs4
module help.
WHen registering a new binfmt_misc handler, it is possible to overflow
the offset to get a negative value, which might crash the system, or
possibly leak kernel data.
Here is a crash log when 2500000000 was used as an offset:
Use kstrtoint instead of simple_strtoul. It will work as the code
already set the delimiter byte to '\0' and we only do it when the field
is not empty.
Tested with offsets -1, 2500000000, UINT_MAX and INT_MAX. Also tested
with examples documented at Documentation/admin-guide/binfmt-misc.rst
and other registrations from packages on Ubuntu.
Link: http://lkml.kernel.org/r/20180529135648.14254-1-cascardo@canonical.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Fri, 8 Jun 2018 00:10:51 +0000 (17:10 -0700)]
lib/mpi: headers cleanup
MPI headers contain definitions for huge number of non-existing
functions.
Most part of these functions was removed in 2012 by Dmitry Kasatkin
- 7cf4206a99d1 ("Remove unused code from MPI library")
- 9e235dcaf4f6 ("Revert "crypto: GnuPG based MPI lib - additional ...")
- bc95eeadf5c6 ("lib/mpi: removed unused functions")
however headers wwere not updated properly.
lib/percpu_ida.c: use _irqsave() instead of local_irq_save() + spin_lock
percpu_ida() decouples disabling interrupts from the locking operations.
This breaks some assumptions if the locking operations are replaced like
they are under -RT.
The same locking can be achieved by avoiding local_irq_save() and using
spin_lock_irqsave() instead. percpu_ida_alloc() gains one more preemption
point because after unlocking the fastpath and before the pool lock is
acquired, the interrupts are briefly enabled.
Link: http://lkml.kernel.org/r/20180504153218.7301-1-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Shaohua Li <shli@fb.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Fri, 8 Jun 2018 00:10:45 +0000 (17:10 -0700)]
lib/idr.c: remove simple_ida_lock
Improve the scalability of the IDA by using the per-IDA xa_lock rather
than the global simple_ida_lock. IDAs are not typically used in
performance-sensitive locations, but since we have this lock anyway, we
can use it. It is also a step towards converting the IDA from the radix
tree to the XArray.
[akpm@linux-foundation.org: idr.c needs xarray.h] Link: http://lkml.kernel.org/r/20180331125332.GF13332@bombadil.infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yury Norov [Fri, 8 Jun 2018 00:10:41 +0000 (17:10 -0700)]
lib/bitmap.c: micro-optimization for __bitmap_complement()
Use BITS_TO_LONGS() macro to avoid calculation of reminder (bits %
BITS_PER_LONG) On ARM64 it saves 5 instruction for function - 16 before
and 11 after.
Link: http://lkml.kernel.org/r/20180411145914.6011-1-ynorov@caviumnetworks.com Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When reporting an AB-BA deadlock like shown above, it would be nice if
trace of PID=6541 is printed as well as trace of PID=6540 before calling
panic().
Showing hung tasks up to /proc/sys/kernel/hung_task_warnings could delay
calling panic() but normally there should not be so many hung tasks.
Link: http://lkml.kernel.org/r/201804050705.BHE57833.HVFOFtSOMQJFOL@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Mandeep Singh Baines <msb@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Masahiro Yamada [Fri, 8 Jun 2018 00:10:24 +0000 (17:10 -0700)]
int-ll64.h: define u{8,16,32,64} and s{8,16,32,64} based on uapi header
<uapi/asm-generic/int-ll64.h> has the same typedefs except that it
prefixes them with double-underscore for user space. Use them for
the kernel space typedefs.
Alexey Dobriyan [Fri, 8 Jun 2018 00:10:20 +0000 (17:10 -0700)]
tools/testing/selftests/proc: test /proc/*/fd a bit (+ PF_KTHREAD is ABI!)
* Test lookup in /proc/self/fd.
"map_files" lookup story showed that lookup is not that simple.
* Test that all those symlinks open the same file.
Check with (st_dev, st_info).
* Test that kernel threads do not have anything in their /proc/*/fd/
directory.
Now this is where things get interesting.
First, kernel threads aren't pinned by /proc/self or equivalent,
thus some "atomicity" is required.
Second, ->comm can contain whitespace and ')'.
No, they are not escaped.
Third, the only reliable way to check if process is kernel thread
appears to be field #9 in /proc/*/stat.
This field is struct task_struct::flags in decimal!
Check is done by testing PF_KTHREAD flags like we do in kernel.
PF_KTREAD value is a part of userspace ABI !!!
Other methods for determining kernel threadness are not reliable:
* RSS can be 0 if everything is swapped, even while reading
from /proc/self.
* ->total_vm CAN BE ZERO if process is finishing
munmap(NULL, whole address space);
* /proc/*/maps and similar files can be empty because unmapping
everything works. Read returning 0 can't distinguish between
kernel thread and such suicide process.
Alexey Dobriyan [Fri, 8 Jun 2018 00:09:59 +0000 (17:09 -0700)]
proc: simpler iterations for /proc/*/cmdline
"rv" variable is used both as a counter of bytes transferred and an
error value holder but it can be reduced solely to error values if
original start of userspace buffer is stashed and used at the very end.
[akpm@linux-foundation.org: simplify cleanup code] Link: http://lkml.kernel.org/r/20180221193009.GA28678@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alexey Dobriyan [Fri, 8 Jun 2018 00:09:52 +0000 (17:09 -0700)]
proc: more "unsigned int" in /proc/*/cmdline
access_remote_vm() doesn't return negative errors, it returns number of
bytes read/written (0 if error occurs). This allows to delete some
comparisons which never trigger.
Reuse "nr_read" variable while I'm at it.
Link: http://lkml.kernel.org/r/20180221192605.GB28548@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sahara [Fri, 8 Jun 2018 00:09:48 +0000 (17:09 -0700)]
mm: remove page_is_poisoned() from linux/mm.h
When commit bd33ef368135 ("mm: enable page poisoning early at boot") got
rid of the PAGE_EXT_DEBUG_POISON, page_is_poisoned in the header left
behind. This patch cleans up the leftovers under the table.
Link: http://lkml.kernel.org/r/1528101069-21637-1-git-send-email-kpark3469@gmail.com Signed-off-by: Sahara <keun-o.park@darkmatter.ae> Acked-by: Michal Hocko <mhocko@suse.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>
Aaron Lu [Fri, 8 Jun 2018 00:09:44 +0000 (17:09 -0700)]
mem_cgroup: make sure moving_account, move_lock_task and stat_cpu in the same cacheline
The LKP robot found a 27% will-it-scale/page_fault3 performance
regression regarding commit e27be240df53("mm: memcg: make sure
memory.events is uptodate when waking pollers").
What the test does is:
1 mkstemp() a 128M file on a tmpfs;
2 start $nr_cpu processes, each to loop the following:
2.1 mmap() this file in shared write mode;
2.2 write 0 to this file in a PAGE_SIZE step till the end of the file;
2.3 unmap() this file and repeat this process.
3 After 5 minutes, check how many loops they managed to complete, the
higher the better.
The commit itself looks innocent enough as it merely changed some event
counting mechanism and this test didn't trigger those events at all.
Perf shows increased cycles spent on accessing root_mem_cgroup->stat_cpu
in count_memcg_event_mm()(called by handle_mm_fault()) and in
__mod_memcg_state() called by page_add_file_rmap(). So it's likely due
to the changed layout of 'struct mem_cgroup' that either make stat_cpu
falling into a constantly modifying cacheline or some hot fields stop
being in the same cacheline.
I verified this by moving memory_events[] back to where it was:
Later investigation found that as long as the following 3 fields
moving_account, move_lock_task and stat_cpu are in the same cacheline,
performance will be good. To avoid future performance surprise by other
commits changing the layout of 'struct mem_cgroup', this patch makes
sure the 3 fields stay in the same cacheline.
One concern of this approach is, moving_account and move_lock_task could
be modified when a process changes memory cgroup while stat_cpu is a
always read field, it might hurt to place them in the same cacheline. I
assume it is rare for a process to change memory cgroup so this should
be OK.
Michal Hocko [Fri, 8 Jun 2018 00:09:40 +0000 (17:09 -0700)]
mm: kvmalloc does not fallback to vmalloc for incompatible gfp flags
kvmalloc warned about incompatible gfp_mask to catch abusers (mostly
GFP_NOFS) with an intention that this will motivate authors of the code
to fix those. Linus argues that this just motivates people to do even
more hacks like
if (gfp == GFP_KERNEL)
kvmalloc
else
kmalloc
I haven't seen this happening much (Linus pointed to bucket_lock special
cases an atomic allocation but my git foo hasn't found much more) but it
is true that we can grow those in future. Therefore Linus suggested to
simply not fallback to vmalloc for incompatible gfp flags and rather
stick with the kmalloc path.
Link: http://lkml.kernel.org/r/20180601115329.27807-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tom Herbert <tom@quantonium.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Huaisheng Ye [Fri, 8 Jun 2018 00:09:36 +0000 (17:09 -0700)]
include/linux/gfp.h: fix the annotation of GFP_ZONE_TABLE
When bit is equal to 0x4, it means OPT_ZONE_DMA32 should be got from
GFP_ZONE_TABLE. OPT_ZONE_DMA32 shall be equal to ZONE_DMA32 or
ZONE_NORMAL according to the status of CONFIG_ZONE_DMA32.
Similarly, when bit is equal to 0xc, that means OPT_ZONE_DMA32 should be
got with an allocation policy GFP_MOVABLE. So ZONE_DMA32 or ZONE_NORMAL
is the possible result value.
Link: http://lkml.kernel.org/r/20180601163403.1032-1-yehs2007@zoho.com Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Fri, 8 Jun 2018 00:09:29 +0000 (17:09 -0700)]
mm, page_alloc: do not break __GFP_THISNODE by zonelist reset
In __alloc_pages_slowpath() we reset zonelist and preferred_zoneref for
allocations that can ignore memory policies. The zonelist is obtained
from current CPU's node. This is a problem for __GFP_THISNODE
allocations that want to allocate on a different node, e.g. because the
allocating thread has been migrated to a different CPU.
This has been observed to break SLAB in our 4.4-based kernel, because
there it relies on __GFP_THISNODE working as intended. If a slab page
is put on wrong node's list, then further list manipulations may corrupt
the list because page_to_nid() is used to determine which node's
list_lock should be locked and thus we may take a wrong lock and race.
Current SLAB implementation seems to be immune by luck thanks to commit 511e3a058812 ("mm/slab: make cache_grow() handle the page allocated on
arbitrary node") but there may be others assuming that __GFP_THISNODE
works as promised.
We can fix it by simply removing the zonelist reset completely. There
is actually no reason to reset it, because memory policies and cpusets
don't affect the zonelist choice in the first place. This was different
when commit 183f6371aac2 ("mm: ignore mempolicies when using
ALLOC_NO_WATERMARK") introduced the code, as mempolicies provided their
own restricted zonelists.
We might consider this for 4.17 although I don't know if there's
anything currently broken.
SLAB is currently not affected, but in kernels older than 4.7 that don't
yet have 511e3a058812 ("mm/slab: make cache_grow() handle the page
allocated on arbitrary node") it is. That's at least 4.4 LTS. Older
ones I'll have to check.
So stable backports should be more important, but will have to be
reviewed carefully, as the code went through many changes. BTW I think
that also the ac->preferred_zoneref reset is currently useless if we
don't also reset ac->nodemask from a mempolicy to NULL first (which we
probably should for the OOM victims etc?), but I would leave that for a
separate patch.
Link: http://lkml.kernel.org/r/20180525130853.13915-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Fixes: 183f6371aac2 ("mm: ignore mempolicies when using ALLOC_NO_WATERMARK") Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Fri, 8 Jun 2018 00:09:25 +0000 (17:09 -0700)]
userfaultfd: prevent non-cooperative events vs mcopy_atomic races
If a process monitored with userfaultfd changes it's memory mappings or
forks() at the same time as uffd monitor fills the process memory with
UFFDIO_COPY, the actual creation of page table entries and copying of
the data in mcopy_atomic may happen either before of after the memory
mapping modifications and there is no way for the uffd monitor to
maintain consistent view of the process memory layout.
For instance, let's consider fork() running in parallel with
userfaultfd_copy():
If the userfaultfd_copy() takes the mmap_sem first, the new page(s) will
be present by the time copy_page_range() is called and they will appear
in the child's memory mappings. However, if the fork() is the first to
take the mmap_sem, the new pages won't be mapped in the child's address
space.
If the pages are not present and child tries to access them, the monitor
will get page fault notification and everything is fine. However, if
the pages *are present*, the child can access them without uffd
noticing. And if we copy them into child it'll see the wrong data.
Since we are talking about background copy, we'd need to decide whether
the pages should be copied or not regardless #PF notifications.
Since userfaultfd monitor has no way to determine what was the order,
let's disallow userfaultfd_copy in parallel with the non-cooperative
events. In such case we return -EAGAIN and the uffd monitor can
understand that userfaultfd_copy() clashed with a non-cooperative event
and take an appropriate action.
Link: http://lkml.kernel.org/r/1527061324-19949-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tejun Heo [Fri, 8 Jun 2018 00:09:21 +0000 (17:09 -0700)]
mm: memcg: allow lowering memory.swap.max below the current usage
Currently an attempt to set swap.max into a value lower than the actual
swap usage fails, which causes configuration problems as there's no way
of lowering the configuration below the current usage short of turning
off swap entirely. This makes swap.max difficult to use and allows
delegatees to lock the delegator out of reducing swap allocation.
This patch updates swap_max_write() so that the limit can be lowered
below the current usage. It doesn't implement active reclaiming of swap
entries for the following reasons.
* mem_cgroup_swap_full() already tells the swap machinary to
aggressively reclaim swap entries if the usage is above 50% of
limit, so simply lowering the limit automatically triggers gradual
reclaim.
* Forcing back swapped out pages is likely to heavily impact the
workload and mess up the working set. Given that swap usually is a
lot less valuable and less scarce, letting the existing usage
dissipate over time through the above gradual reclaim and as they're
falted back in is likely the better behavior.
Link: http://lkml.kernel.org/r/20180523185041.GR1718769@devbig577.frc2.facebook.com Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: Rik van Riel <riel@surriel.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Shaohua Li <shli@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use new return type vm_fault_t for fault handler. For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno. Once all instances are converted, vm_fault_t will become a
distinct type.
See commit 1c8f422059ae ("mm: change return type to vm_fault_t")
vmf_error() is the newly introduce inline function in 4.17-rc6.
Matthew Wilcox [Fri, 8 Jun 2018 00:09:10 +0000 (17:09 -0700)]
slub: remove kmem_cache->reserved
The reserved field was only used for embedding an rcu_head in the data
structure. With the previous commit, we no longer need it. That lets us
remove the 'reserved' argument to a lot of functions.
Link: http://lkml.kernel.org/r/20180518194519.3820-16-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Fri, 8 Jun 2018 00:08:57 +0000 (17:08 -0700)]
mm: add pt_mm to struct page
For pgd page table pages, x86 overloads the page->index field to store a
pointer to the mm_struct. Rename this to pt_mm so it's visible to other
users.
Link: http://lkml.kernel.org/r/20180518194519.3820-13-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Fri, 8 Jun 2018 00:08:50 +0000 (17:08 -0700)]
mm: combine LRU and main union in struct page
This gives us five words of space in a single union in struct page. The
compound_mapcount moves position (from offset 24 to offset 20) on 64-bit
systems, but that does not seem likely to cause any trouble.
Link: http://lkml.kernel.org/r/20180518194519.3820-11-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Fri, 8 Jun 2018 00:08:39 +0000 (17:08 -0700)]
mm: combine first three unions in struct page
By combining these three one-word unions into one three-word union, we
make it easier for users to add their own multi-word fields to struct
page, as well as making it obvious that SLUB needs to keep its double-word
alignment for its freelist & counters.
No field moves position; verified with pahole.
Link: http://lkml.kernel.org/r/20180518194519.3820-8-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Fri, 8 Jun 2018 00:08:35 +0000 (17:08 -0700)]
mm: move _refcount out of struct page union
Keeping the refcount in the union only encourages people to put something
else in the union which will overlap with _refcount and eventually explode
messily. pahole reports no fields change location.
Link: http://lkml.kernel.org/r/20180518194519.3820-7-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Fri, 8 Jun 2018 00:08:31 +0000 (17:08 -0700)]
mm: move 'private' union within struct page
By moving page->private to the fourth word of struct page, we can put the
SLUB counters in the same word as SLAB's s_mem and still do the
cmpxchg_double trick. Now the SLUB counters no longer overlap with the
mapcount or refcount so we can drop the call to page_mapcount_reset() and
simplify set_page_slub_counters() to a single line.
Link: http://lkml.kernel.org/r/20180518194519.3820-6-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Fri, 8 Jun 2018 00:08:26 +0000 (17:08 -0700)]
mm: switch s_mem and slab_cache in struct page
This will allow us to store slub's counters in the same bits as slab's
s_mem. slub now needs to set page->mapping to NULL as it frees the page,
just like slab does.
Link: http://lkml.kernel.org/r/20180518194519.3820-5-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Fri, 8 Jun 2018 00:08:23 +0000 (17:08 -0700)]
mm: mark pages in use for page tables
Define a new PageTable bit in the page_type and use it to mark pages in
use as page tables. This can be helpful when debugging crashdumps or
analysing memory fragmentation. Add a KPF flag to report these pages to
userspace and update page-types.c to interpret that flag.
Note that only pages currently accounted as NR_PAGETABLES are tracked as
PageTable; this does not include pgd/p4d/pud/pmd pages. Those will be the
subject of a later patch.
Link: http://lkml.kernel.org/r/20180518194519.3820-4-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Fri, 8 Jun 2018 00:08:18 +0000 (17:08 -0700)]
mm: split page_type out from _mapcount
We're already using a union of many fields here, so stop abusing the
_mapcount and make page_type its own field. That implies renaming some of
the machinery that creates PageBuddy, PageBalloon and PageKmemcg; bring
back the PG_buddy, PG_balloon and PG_kmemcg names.
As suggested by Kirill, make page_type a bitmask. Because it starts out
life as -1 (thanks to sharing the storage with _mapcount), setting a page
flag means clearing the appropriate bit. This gives us space for probably
twenty or so extra bits (depending how paranoid we want to be about
_mapcount underflow).
Link: http://lkml.kernel.org/r/20180518194519.3820-3-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Fri, 8 Jun 2018 00:08:15 +0000 (17:08 -0700)]
s390: use _refcount for pgtables
Patch series "Rearrange struct page", v6.
As presented at LSFMM, this patch-set rearranges struct page to give
more contiguous usable space to users who have allocated a struct page
for their own purposes. For a graphical view of before-and-after, see
the first two tabs of
Highlights:
- deferred_list now really exists in struct page instead of just a comment.
- hmm_data also exists in struct page instead of being a nasty hack.
- x86's PGD pages have a real pointer to the mm_struct.
- VMalloc pages now have all sorts of extra information stored in them
to help with debugging and tuning.
- rcu_head is no longer tied to slab in case anyone else wants to
free pages by RCU.
- slub's counters no longer share space with _refcount.
- slub's freelist+counters are now naturally dword aligned.
- slub loses a parameter to a lot of functions and a sysfs file.
This patch (of 17):
s390 borrows the storage used for _mapcount in struct page in order to
account whether the bottom or top half is being used for 2kB page tables.
I want to use that for something else, so use the top byte of _refcount
instead of the bottom byte of _mapcount. _refcount may temporarily be
incremented by other CPUs that see a stale pointer to this page in the
page cache, but each CPU can only increment it by one, and there are no
systems with 2^24 CPUs today, so they will not change the upper byte of
_refcount. We do have to be a little careful not to lose any of their
writes (as they will subsequently decrement the counter).
Link: http://lkml.kernel.org/r/20180518194519.3820-2-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Huang Ying [Fri, 8 Jun 2018 00:08:08 +0000 (17:08 -0700)]
mm, hugetlbfs: pass fault address to no page handler
This is to take better advantage of general huge page clearing
optimization (commit c79b57e462b5: "mm: hugetlb: clear target sub-page
last when clearing huge page") for hugetlbfs.
In the general optimization patch, the sub-page to access will be
cleared last to avoid the cache lines of to access sub-page to be
evicted when clearing other sub-pages. This works better if we have the
address of the sub-page to access, that is, the fault address inside the
huge page. So the hugetlbfs no page fault handler is changed to pass
that information. This will benefit workloads which don't access the
begin of the hugetlbfs huge page after the page fault under heavy cache
contention for shared last level cache.
The patch is a generic optimization which should benefit quite some
workloads, not for a specific use case. To demonstrate the performance
benefit of the patch, we tested it with vm-scalability run on hugetlbfs.
With this patch, the throughput increases ~28.1% in vm-scalability
anon-w-seq test case with 88 processes on a 2 socket Xeon E5 2699 v4
system (44 cores, 88 threads). The test case creates 88 processes, each
process mmaps a big anonymous memory area with MAP_HUGETLB and writes to
it from the end to the begin. For each process, other processes could
be seen as other workload which generates heavy cache pressure. At the
same time, the cache miss rate reduced from ~36.3% to ~25.6%, the IPC
(instruction per cycle) increased from 0.3 to 0.37, and the time spent
in user space is reduced ~19.3%.
Link: http://lkml.kernel.org/r/20180517083539.9242-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shaohua Li <shli@fb.com> Cc: Christopher Lameter <cl@linux.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Punit Agrawal <punit.agrawal@arm.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use new return type vm_fault_t for fault handler in struct
vm_operations_struct. For now, this is just documenting that the
function returns a VM_FAULT value rather than an errno. Once all
instances are converted, vm_fault_t will become a distinct type.
See commit 1c8f422059ae ("mm: change return type to vm_fault_t")
Link: http://lkml.kernel.org/r/20180512063745.GA26866@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use new return type vm_fault_t for fault handler in struct
vm_operations_struct. For now, this is just documenting that the
function returns a VM_FAULT value rather than an errno. Once all
instances are converted, vm_fault_t will become a distinct type.
Link: http://lkml.kernel.org/r/20180511190542.GA2412@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Huaisheng Ye [Fri, 8 Jun 2018 00:07:57 +0000 (17:07 -0700)]
mm/page_alloc.c: remove useless parameter of finalise_ac()
finalise_ac() has parameter order which is not used at all. Remove it.
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com> Acked-by: Michal Hocko <mhocko@suse.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>
Roman Gushchin [Fri, 8 Jun 2018 00:07:46 +0000 (17:07 -0700)]
memcg: introduce memory.min
Memory controller implements the memory.low best-effort memory
protection mechanism, which works perfectly in many cases and allows
protecting working sets of important workloads from sudden reclaim.
But its semantics has a significant limitation: it works only as long as
there is a supply of reclaimable memory. This makes it pretty useless
against any sort of slow memory leaks or memory usage increases. This
is especially true for swapless systems. If swap is enabled, memory
soft protection effectively postpones problems, allowing a leaking
application to fill all swap area, which makes no sense. The only
effective way to guarantee the memory protection in this case is to
invoke the OOM killer.
It's possible to handle this case in userspace by reacting on MEMCG_LOW
events; but there is still a place for a fail-safe in-kernel mechanism
to provide stronger guarantees.
This patch introduces the memory.min interface for cgroup v2 memory
controller. It works very similarly to memory.low (sharing the same
hierarchical behavior), except that it's not disabled if there is no
more reclaimable memory in the system.
If cgroup is not populated, its memory.min is ignored, because otherwise
even the OOM killer wouldn't be able to reclaim the protected memory,
and the system can stall.
mm: move is_pageblock_removable_nolock() to mm/memory_hotplug.c
is_pageblock_removable_nolock() is not used outside of
mm/memory_hotplug.c. Move it next to unique caller
is_mem_section_removable() and make it static.
Remove prototype in <linux/memory_hotplug.h> to silence gcc warning (W=1):
mm/page_alloc.c:7704:6: warning: no previous prototype for `is_pageblock_removable_nolock' [-Wmissing-prototypes]
Link: http://lkml.kernel.org/r/20180509190001.24789-1-malat@debian.org Signed-off-by: Mathieu Malaterre <malat@debian.org> Suggested-by: Michal Hocko <mhocko@kernel.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Huang Ying [Fri, 8 Jun 2018 00:07:39 +0000 (17:07 -0700)]
mm: /proc/pid/pagemap: hide swap entries from unprivileged users
In commit ab676b7d6fbf ("pagemap: do not leak physical addresses to
non-privileged userspace"), the /proc/PID/pagemap is restricted to be
readable only by CAP_SYS_ADMIN to address some security issue.
In commit 1c90308e7a77 ("pagemap: hide physical addresses from
non-privileged users"), the restriction is relieved to make
/proc/PID/pagemap readable, but hide the physical addresses for
non-privileged users.
But the swap entries are readable for non-privileged users too. This
has some security issues. For example, for page under migrating, the
swap entry has physical address information. So, in this patch, the
swap entries are hided for non-privileged users too.
Link: http://lkml.kernel.org/r/20180508012745.7238-1-ying.huang@intel.com Fixes: 1c90308e7a77 ("pagemap: hide physical addresses from non-privileged users") Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Andrei Vagin <avagin@openvz.org> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Daniel Colascione <dancol@google.com> Cc: Zi Yan <zi.yan@cs.rutgers.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Junaid Shahid [Fri, 8 Jun 2018 00:07:31 +0000 (17:07 -0700)]
mm: memcontrol: drain memcg stock on force_empty
The per-cpu memcg stock can retain a charge of upto 32 pages. On a
machine with large number of cpus, this can amount to a decent amount of
memory. Additionally force_empty interface might be triggering unneeded
memcg reclaims.
Link: http://lkml.kernel.org/r/20180507201651.165879-1-shakeelb@google.com Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Greg Thelen <gthelen@google.com> 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>
Shakeel Butt [Fri, 8 Jun 2018 00:07:27 +0000 (17:07 -0700)]
mm: memcontrol: drain stocks on resize limit
Resizing the memcg limit for cgroup-v2 drains the stocks before
triggering the memcg reclaim. Do the same for cgroup-v1 to make the
behavior consistent.
Link: http://lkml.kernel.org/r/20180504205548.110696-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Greg Thelen <gthelen@google.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>
Wang Long [Fri, 8 Jun 2018 00:07:19 +0000 (17:07 -0700)]
memcg: writeback: use memcg->cgwb_list directly
mem_cgroup_cgwb_list is a very simple wrapper and it will never be used
outside of code under CONFIG_CGROUP_WRITEBACK. so use memcg->cgwb_list
directly.
Link: http://lkml.kernel.org/r/1524406173-212182-1-git-send-email-wanglong19@meituan.com Signed-off-by: Wang Long <wanglong19@meituan.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Amir Goldstein [Fri, 8 Jun 2018 00:07:15 +0000 (17:07 -0700)]
tmpfs: allow decoding a file handle of an unlinked file
tmpfs uses the helper d_find_alias() to find a dentry from a decoded
inode, but d_find_alias() skips unhashed dentries, so unlinked files
cannot be decoded from a file handle.
This can be reproduced using xfstests test program open_by_handle:
$ open_by handle -c /tmp/testdir
$ open_by_handle -dk /tmp/testdir
open_by_handle(/tmp/testdir/file000000) returned 116 incorrectly on an unlinked open file!
To fix this, if d_find_alias() can't find a hashed alias, call
d_find_any_alias() to return an unhashed one.
Link: http://lkml.kernel.org/r/CAOQ4uxg+qSLP0KwdW+h1tcPqOCQd+_pGZVXiePQB1TXCMBMctQ@mail.gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: NeilBrown <neilb@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 9f32624be943 ("mm/rmap: use rmap_walk() in page_referenced()")
removed the declaration of page_referenced_ksm for the case
CONFIG_KSM=y, but left one for CONFIG_KSM=n.
Remove the unused leftover.
Link: http://lkml.kernel.org/r/1524552106-7356-2-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Omar Sandoval [Fri, 8 Jun 2018 00:07:02 +0000 (17:07 -0700)]
lockdep: fix fs_reclaim annotation
While revisiting my Btrfs swapfile series [1], I introduced a situation
in which reclaim would lock i_rwsem, and even though the swapon() path
clearly made GFP_KERNEL allocations while holding i_rwsem, I got no
complaints from lockdep. It turns out that the rework of the fs_reclaim
annotation was broken: if the current task has PF_MEMALLOC set, we don't
acquire the dummy fs_reclaim lock, but when reclaiming we always check
this _after_ we've just set the PF_MEMALLOC flag. In most cases, we can
fix this by moving the fs_reclaim_{acquire,release}() outside of the
memalloc_noreclaim_{save,restore}(), althought kswapd is slightly
different. After applying this, I got the expected lockdep splats.
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