Linus Torvalds [Fri, 15 Jan 2016 20:28:00 +0000 (12:28 -0800)]
Merge tag 'md/4.5' of git://neil.brown.name/md
Pull md updates from Neil Brown:
"Mostly clustered-raid1 and raid5 journal updates. one Y2038 fix and
other minor stuff.
One patch removes me from the MAINTAINERS file and adds a record of my
md maintainership to Credits"
Many thanks to Neil, who has been around for a _looong_ time.
* tag 'md/4.5' of git://neil.brown.name/md: (26 commits)
md/raid: only permit hot-add of compatible integrity profiles
Remove myself as MD Maintainer, and add to Credits.
raid5-cache: handle journal hotadd in quiesce
MD: add journal with array suspended
md: set MD_HAS_JOURNAL in correct places
md: Remove 'ready' field from mddev.
md: remove unnecesary md_new_event_inintr
raid5: allow r5l_io_unit allocations to fail
raid5-cache: use a mempool for the metadata block
raid5-cache: use a bio_set
raid5-cache: add journal hot add/remove support
drivers: md: use ktime_get_real_seconds()
md: avoid warning for 32-bit sector_t
raid5-cache: free meta_page earlier
raid5-cache: simplify r5l_move_io_unit_list
md: update comment for md_allow_write
md-cluster: update comments for MD_CLUSTER_SEND_LOCKED_ALREADY
md-cluster: Protect communication with mutexes
md-cluster: Defer MD reloading to mddev->thread
md-cluster: update the documentation
...
Linus Torvalds [Fri, 15 Jan 2016 20:14:47 +0000 (12:14 -0800)]
Merge tag 'regulator-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator updates from Mark Brown:
"Aside from a fix for a spurious warning (which caused more problems
than it fixed in the fixing really) this is all driver updates,
including new drivers for Dialog PV88060/90 and TI LM363x and TPS65086
devices. The qcom_smd driver has had PM8916 and PMA8084 support
added"
* tag 'regulator-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (36 commits)
regulator: core: remove some dead code
regulator: core: use dev_to_rdev
regulator: lp872x: Get rid of duplicate reference to DVS GPIO
regulator: lp872x: Add missing of_match in regulators descriptions
regulator: axp20x: Fix GPIO LDO enable value for AXP22x
regulator: lp8788: constify regulator_ops structures
regulator: wm8*: constify regulator_ops structures
regulator: da9*: constify regulator_ops structures
regulator: mt6311: Use REGCACHE_RBTREE
regulator: tps65917/palmas: Add bypass ops for LDOs with bypass capability
regulator: qcom-smd: Add support for PMA8084
regulator: qcom-smd: Add PM8916 support
soc: qcom: documentation: Update SMD/RPM Docs
regulator: pv88090: logical vs bitwise AND typo
regulator: pv88090: Fix irq leak
regulator: pv88090: new regulator driver
regulator: wm831x-ldo: Use platform_register/unregister_drivers()
regulator: wm831x-dcdc: Use platform_register/unregister_drivers()
regulator: lp8788-ldo: Use platform_register/unregister_drivers()
regulator: core: Fix nested locking of supplies
...
Borislav Petkov [Fri, 15 Jan 2016 18:26:44 +0000 (19:26 +0100)]
amdkfd: Copy from the proper user command pointer
8f1d57c17248 ("amdkfd: don't open-code memdup_user()") mistakenly uses
an uninitialized local pointer, gcc complains:
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c: In function ‘kfd_ioctl_dbg_address_watch’:
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c:562:12: warning: ‘args_buff’ may be used uninitialized in this function [-Wmaybe-uninitialized]
args_buff = memdup_user(args_buff,
^
Fix it.
Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Linus Torvalds [Fri, 15 Jan 2016 19:51:51 +0000 (11:51 -0800)]
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull UDF fixes and quota cleanups from Jan Kara:
"Several UDF fixes and some minor quota cleanups"
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
udf: Check output buffer length when converting name to CS0
udf: Prevent buffer overrun with multi-byte characters
quota: constify qtree_fmt_operations structures
udf: avoid uninitialized variable use
udf: Fix lost indirect extent block
udf: Factor out code for creating indirect extent
udf: limit the maximum number of indirect extents in a row
udf: limit the maximum number of TD redirections
fs: make quota/dquot.c explicitly non-modular
fs: make quota/netlink.c explicitly non-modular
Linus Torvalds [Fri, 15 Jan 2016 19:41:44 +0000 (11:41 -0800)]
Merge branch 'akpm' (patches from Andrew)
Merge first patch-bomb from Andrew Morton:
- A few hotfixes which missed 4.4 becasue I was asleep. cc'ed to
-stable
- A few misc fixes
- OCFS2 updates
- Part of MM. Including pretty large changes to page-flags handling
and to thp management which have been buffered up for 2-3 cycles now.
I have a lot of MM material this time.
[ It turns out the THP part wasn't quite ready, so that got dropped from
this series - Linus ]
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (117 commits)
zsmalloc: reorganize struct size_class to pack 4 bytes hole
mm/zbud.c: use list_last_entry() instead of list_tail_entry()
zram/zcomp: do not zero out zcomp private pages
zram: pass gfp from zcomp frontend to backend
zram: try vmalloc() after kmalloc()
zram/zcomp: use GFP_NOIO to allocate streams
mm: add tracepoint for scanning pages
drivers/base/memory.c: fix kernel warning during memory hotplug on ppc64
mm/page_isolation: use macro to judge the alignment
mm: fix noisy sparse warning in LIBCFS_ALLOC_PRE()
mm: rework virtual memory accounting
include/linux/memblock.h: fix ordering of 'flags' argument in comments
mm: move lru_to_page to mm_inline.h
Documentation/filesystems: describe the shared memory usage/accounting
memory-hotplug: don't BUG() in register_memory_resource()
hugetlb: make mm and fs code explicitly non-modular
mm/swapfile.c: use list_for_each_entry_safe in free_swap_count_continuations
mm: /proc/pid/clear_refs: no need to clear VM_SOFTDIRTY in clear_soft_dirty_pmd()
mm: make sure isolate_lru_page() is never called for tail page
vmstat: make vmstat_updater deferrable again and shut down on idle
...
Do not __GFP_ZERO allocated zcomp ->private pages. We keep allocated
streams around and use them for read/write requests, so we supply a
zeroed out ->private to compression algorithm as a scratch buffer only
once -- the first time we use that stream. For the rest of IO requests
served by this stream ->private usually contains some temporarily data
from the previous requests.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Thu, 14 Jan 2016 23:22:32 +0000 (15:22 -0800)]
zram: pass gfp from zcomp frontend to backend
Each zcomp backend uses own gfp flag but it's pointless because the
context they could be called is driven by upper layer(ie, zcomp
frontend). As well, zcomp frondend could call them in different
context. One context(ie, zram init part) is it should be better to make
sure successful allocation other context(ie, further stream allocation
part for accelarating I/O speed) is just optional so let's pass gfp down
from driver (ie, zcomp frontend) like normal MM convention.
[sergey.senozhatsky@gmail.com: add missing __vmalloc zero and highmem gfps] Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kyeongdon Kim [Thu, 14 Jan 2016 23:22:29 +0000 (15:22 -0800)]
zram: try vmalloc() after kmalloc()
When we're using LZ4 multi compression streams for zram swap, we found
out page allocation failure message in system running test. That was
not only once, but a few(2 - 5 times per test). Also, some failure
cases were continually occurring to try allocation order 3.
In order to make parallel compression private data, we should call
kzalloc() with order 2/3 in runtime(lzo/lz4). But if there is no order
2/3 size memory to allocate in that time, page allocation fails. This
patch makes to use vmalloc() as fallback of kmalloc(), this prevents
page alloc failure warning.
After using this, we never found warning message in running test, also
It could reduce process startup latency about 60-120ms in each case.
We can end up allocating a new compression stream with GFP_KERNEL from
within the IO path, which may result is nested (recursive) IO
operations. That can introduce problems if the IO path in question is a
reclaimer, holding some locks that will deadlock nested IOs.
Allocate streams and working memory using GFP_NOIO flag, forbidding
recursive IO and FS operations.
An example:
inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
git/20158 [HC0[0]:SC0[0]:HE1:SE1] takes:
(jbd2_handle){+.+.?.}, at: start_this_handle+0x4ca/0x555
{IN-RECLAIM_FS-W} state was registered at:
__lock_acquire+0x8da/0x117b
lock_acquire+0x10c/0x1a7
start_this_handle+0x52d/0x555
jbd2__journal_start+0xb4/0x237
__ext4_journal_start_sb+0x108/0x17e
ext4_dirty_inode+0x32/0x61
__mark_inode_dirty+0x16b/0x60c
iput+0x11e/0x274
__dentry_kill+0x148/0x1b8
shrink_dentry_list+0x274/0x44a
prune_dcache_sb+0x4a/0x55
super_cache_scan+0xfc/0x176
shrink_slab.part.14.constprop.25+0x2a2/0x4d3
shrink_zone+0x74/0x140
kswapd+0x6b7/0x930
kthread+0x107/0x10f
ret_from_fork+0x3f/0x70
irq event stamp: 138297
hardirqs last enabled at (138297): debug_check_no_locks_freed+0x113/0x12f
hardirqs last disabled at (138296): debug_check_no_locks_freed+0x33/0x12f
softirqs last enabled at (137818): __do_softirq+0x2d3/0x3e9
softirqs last disabled at (137813): irq_exit+0x41/0x95
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(jbd2_handle);
<Interrupt>
lock(jbd2_handle);
Linus Torvalds [Fri, 15 Jan 2016 01:04:19 +0000 (17:04 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
floppy: make local variable non-static
exynos: fixes an incorrect header guard
dt-bindings: fixes some incorrect header guards
cpufreq-dt: correct dead link in documentation
cpufreq: ARM big LITTLE: correct dead link in documentation
treewide: Fix typos in printk
Documentation: filesystem: Fix typo in fs/eventfd.c
fs/super.c: use && instead of & for warn_on condition
Documentation: fix sysfs-ptp
lib: scatterlist: fix Kconfig description
Linus Torvalds [Fri, 15 Jan 2016 00:38:02 +0000 (16:38 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching updates from Jiri Kosina:
- RO/NX attribute fixes for patch module relocations from Josh
Poimboeuf. As part of this effort, module.c has been cleaned up as
well and livepatching is piggy-backing on this cleanup. Rusty is OK
with this whole lot going through livepatching tree.
- symbol disambiguation support from Chris J Arges. That series is
also
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
but this came in only after I've alredy pushed out. Didn't want to
rebase because of that, hence I am mentioning it here.
- symbol lookup fix from Miroslav Benes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
livepatch: Cleanup module page permission changes
module: keep percpu symbols in module's symtab
module: clean up RO/NX handling.
module: use a structure to encapsulate layout.
gcov: use within_module() helper.
module: Use the same logic for setting and unsetting RO/NX
livepatch: function,sympos scheme in livepatch sysfs directory
livepatch: add sympos as disambiguator field to klp_reloc
livepatch: add old_sympos as disambiguator field to klp_func
Linus Torvalds [Fri, 15 Jan 2016 00:20:42 +0000 (16:20 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Pull HID updates from Jiri Kosina:
- appoint Benjamin Tissoires as co-maintainer / designated reviewer
- sysfs report_descriptor visibility fix for unclaimed devices, from
Andy Lutomirski
- suspend/resume fixes for Sony driver from Frank Praznik
- IRQ deadlock fix from Ioan-Adrian Ratiu
- hid-i2c fixes affecting (at least) Yoga 900 from Mika Westerberg and
Srinivas Pandruvada
- a lot of new device support (especially, but not limited to, Wacom)
and assorted small misc fixes
- almost complete G920 support; the only bit that is missing is
switching the device to HID mode automatically; Simon Wood and Michal
Maly are working on it.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (46 commits)
Revert "INPUT: xpad: switch Logitech G920 Wheel into HID mode"
HID: sensor-hub: Add quirk for Lenovo Yoga 900 with ITE Chips
HID: Add new PID for Microchip Pick16F1454
HID: wacom: Use correct report to query pen ID from INTUOSHT2 devices
HID: i2c-hid: Prevent sending reports from racing with device reset
HID: use kobj_to_dev()
HID: wiimote: use dev_to_wii()
HID: add a new helper to_hid_driver()
HID: use to_hid_device()
HID: move to_hid_device() to hid.h
HID: usbhid: use to_usb_device
HID: corsair: Convert to use module_hid_driver
HID: input: ignore the battery in OKLICK Laser BTmouse
HID: wacom: Fix pad button range for CINTIQ_COMPANION_2
HID: wacom: Fix touchring value reporting
HID: wacom: Report 'strip2' values in ABS_RY
HID: wacom: Limit touchstrip data to 13 bits
HID: wacom: bitwise vs logical ORs
HID: wacom: Apply lowres quirk to BAMBOO_TOUCH devices
HID: enable hid device to suspend/resume asynchronously
...
Linus Torvalds [Fri, 15 Jan 2016 00:08:23 +0000 (16:08 -0800)]
Merge tag 'nfs-for-4.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"Highlights include:
Stable fixes:
- Fix a regression in the SunRPC socket polling code
- Fix the attribute cache revalidation code
- Fix race in __update_open_stateid()
- Fix an lo->plh_block_lgets imbalance in layoutreturn
- Fix an Oopsable typo in ff_mirror_match_fh()
Features:
- pNFS layout recall performance improvements.
- pNFS/flexfiles: Support server-supplied layoutstats sampling period
Bugfixes + cleanups:
- NFSv4: Don't perform cached access checks before we've OPENed the
file
- Fix starvation issues with background flushes
- Reclaim writes should be flushed as unstable writes if there are
already entries in the commit lists
- Various bugfixes from Chuck to fix NFS/RDMA send queue ordering
problems
- Ensure that we propagate fatal layoutget errors back to the
application
- Fixes for sundry flexfiles layoutstats bugs
- Fix files/flexfiles to not cache invalidated layouts in the DS
commit buckets"
* tag 'nfs-for-4.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (68 commits)
NFS: Fix a compile warning about unused variable in nfs_generic_pg_pgios()
NFSv4: Fix a compile warning about no prototype for nfs4_ioctl()
NFS: Use wait_on_atomic_t() for unlock after readahead
SUNRPC: Fixup socket wait for memory
NFSv4.1/pNFS: Cleanup constify struct pnfs_layout_range arguments
NFSv4.1/pnfs: Cleanup copying of pnfs_layout_range structures
NFSv4.1/pNFS: Cleanup pnfs_mark_matching_lsegs_invalid()
NFSv4.1/pNFS: Fix a race in initiate_file_draining()
NFSv4.1/pNFS: pnfs_error_mark_layout_for_return() must always return layout
NFSv4.1/pNFS: pnfs_mark_matching_lsegs_return() should set the iomode
NFSv4.1/pNFS: Use nfs4_stateid_copy for copying stateids
NFSv4.1/pNFS: Don't pass stateids by value to pnfs_send_layoutreturn()
NFS: Relax requirements in nfs_flush_incompatible
NFSv4.1/pNFS: Don't queue up a new commit if the layout segment is invalid
NFS: Allow multiple commit requests in flight per file
NFS/pNFS: Fix up pNFS write reschedule layering violations and bugs
SUNRPC: Fix a missing break in rpc_anyaddr()
pNFS/flexfiles: Fix an Oopsable typo in ff_mirror_match_fh()
NFS: Fix attribute cache revalidation
NFS: Ensure we revalidate attributes before using execute_ok()
...
Ebru Akagunduz [Thu, 14 Jan 2016 23:22:19 +0000 (15:22 -0800)]
mm: add tracepoint for scanning pages
This patch series makes swapin readahead up to a certain number to gain
more thp performance and adds tracepoint for khugepaged_scan_pmd,
collapse_huge_page, __collapse_huge_page_isolate.
This patch series was written to deal with programs that access most,
but not all, of their memory after they get swapped out. Currently
these programs do not get their memory collapsed into THPs after the
system swapped their memory out, while they would get THPs before
swapping happened.
This patch series was tested with a test program, it allocates 400MB of
memory, writes to it, and then sleeps. I force the system to swap out
all. Afterwards, the test program touches the area by writing and
leaves a piece of it without writing. This shows how much swap in
readahead made by the patch.
John Allen [Thu, 14 Jan 2016 23:22:16 +0000 (15:22 -0800)]
drivers/base/memory.c: fix kernel warning during memory hotplug on ppc64
Fix a bug where a kernel warning is triggered when performing a memory
hotplug on ppc64. This warning may also occur on any architecture that
uses the memory_probe_store interface.
The warning is triggered because there is a udev rule that automatically
tries to online memory after it has been added. The udev rule varies
from distro to distro, but will generally look something like:
On any architecture that uses memory_probe_store to reserve memory, the
udev rule will be triggered after the first section of the block is
reserved and will subsequently attempt to online the entire block,
interrupting the memory reservation process and causing the warning.
This patch modifies memory_probe_store to add a block of memory with a
single call to add_memory as opposed to looping through and adding each
section individually. A single call to add_memory is protected by the
mem_hotplug mutex which will prevent the udev rule from onlining memory
until the reservation of the entire block is complete.
Signed-off-by: John Allen <jallen@linux.vnet.ibm.com> Acked-by: Dave Hansen <dave.hansen@intel.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When inspecting a vague code inside prctl(PR_SET_MM_MEM) call (which
testing the RLIMIT_DATA value to figure out if we're allowed to assign
new @start_brk, @brk, @start_data, @end_data from mm_struct) it's been
commited that RLIMIT_DATA in a form it's implemented now doesn't do
anything useful because most of user-space libraries use mmap() syscall
for dynamic memory allocations.
Linus suggested to convert RLIMIT_DATA rlimit into something suitable
for anonymous memory accounting. But in this patch we go further, and
the changes are bundled together as:
* keep vma counting if CONFIG_PROC_FS=n, will be used for limits
* replace mm->shared_vm with better defined mm->data_vm
* account anonymous executable areas as executable
* account file-backed growsdown/up areas as stack
* drop struct file* argument from vm_stat_account
* enforce RLIMIT_DATA for size of data areas
This way code looks cleaner: now code/stack/data classification depends
only on vm_flags state:
Florian Fainelli [Thu, 14 Jan 2016 23:22:04 +0000 (15:22 -0800)]
include/linux/memblock.h: fix ordering of 'flags' argument in comments
for_each_free_mem_range() and for_each_free_mem_range_reverse() both
accept a 'flags' argument, the comment surrounding the macro placed the
'flags' documentation at the very end, while 'flags' is in fact the 3rd
argument to the macro, so let's preserve natural ordering here.
Fixes: fc6daaf931518 ("mm/memblock: add extra "flags" to memblock to allow selection of memory based on attribute") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rodrigo Freire [Thu, 14 Jan 2016 23:21:58 +0000 (15:21 -0800)]
Documentation/filesystems: describe the shared memory usage/accounting
The Shared Memory accounting support is present in Kernel since commit 4b02108ac1b3 ("mm: oom analysis: add shmem vmstat") and in userland
free(1) since 2014. This patch updates the Documentation to reflect
this change.
Vitaly Kuznetsov [Thu, 14 Jan 2016 23:21:55 +0000 (15:21 -0800)]
memory-hotplug: don't BUG() in register_memory_resource()
Out of memory condition is not a bug and while we can't add new memory
in such case crashing the system seems wrong. Propagating the return
value from register_memory_resource() requires interface change.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Sheng Yong <shengyong1@huawei.com> Cc: Zhu Guihua <zhugh.fnst@cn.fujitsu.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Paul Gortmaker [Thu, 14 Jan 2016 23:21:52 +0000 (15:21 -0800)]
hugetlb: make mm and fs code explicitly non-modular
The Kconfig currently controlling compilation of this code is:
config HUGETLBFS
bool "HugeTLB file system support"
...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that when
reading the driver there is no doubt it is builtin-only.
Since module_init translates to device_initcall in the non-modular case,
the init ordering gets moved to earlier levels when we use the more
appropriate initcalls here.
Originally I had the fs part and the mm part as separate commits, just
by happenstance of the nature of how I detected these non-modular use
cases. But that can possibly introduce regressions if the patch merge
ordering puts the fs part 1st -- as the 0-day testing reported a splat
at mount time.
Investigating with "initcall_debug" showed that the delta was
init_hugetlbfs_fs being called _before_ hugetlb_init instead of after. So
both the fs change and the mm change are here together.
In addition, it worked before due to luck of link order, since they were
both in the same initcall category. So we now have the fs part using
fs_initcall, and the mm part using subsys_initcall, which puts it one
bucket earlier. It now passes the basic sanity test that failed in
earlier 0-day testing.
We delete the MODULE_LICENSE tag and capture that information at the top
of the file alongside author comments, etc.
We don't replace module.h with init.h since the file already has that.
Also note that MODULE_ALIAS is a no-op for non-modular code.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Reported-by: kernel test robot <ying.huang@linux.intel.com> Cc: Nadia Yvette Chambers <nyc@holomorphy.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vmstat: make vmstat_updater deferrable again and shut down on idle
Currently the vmstat updater is not deferrable as a result of commit ba4877b9ca51 ("vmstat: do not use deferrable delayed work for
vmstat_update"). This in turn can cause multiple interruptions of the
applications because the vmstat updater may run at
Make vmstate_update deferrable again and provide a function that folds
the differentials when the processor is going to idle mode thus
addressing the issue of the above commit in a clean way.
Note that the shepherd thread will continue scanning the differentials
from another processor and will reenable the vmstat workers if it
detects any changes.
Fixes: ba4877b9ca51 ("vmstat: do not use deferrable delayed work for vmstat_update") Signed-off-by: Christoph Lameter <cl@linux.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 14 Jan 2016 23:21:37 +0000 (15:21 -0800)]
memcg: avoid vmpressure oops when memcg disabled
A CONFIG_MEMCG=y kernel booted with "cgroup_disable=memory" crashes on a
NULL memcg (but non-NULL root_mem_cgroup) when vmpressure kicks in.
Here's the patch I use to avoid that, but you might prefer a test on
mem_cgroup_disabled() somewhere.
Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: David S. Miller <davem@davemloft.net> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:21:34 +0000 (15:21 -0800)]
mm: memcontrol: switch to the updated jump-label API
According to <linux/jump_label.h> the direct use of struct static_key is
deprecated. Update the socket and slab accounting code accordingly.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David S. Miller <davem@davemloft.net> Reported-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:21:32 +0000 (15:21 -0800)]
mm: memcontrol: hook up vmpressure to socket pressure
Let the networking stack know when a memcg is under reclaim pressure so
that it can clamp its transmit windows accordingly.
Whenever the reclaim efficiency of a cgroup's LRU lists drops low enough
for a MEDIUM or HIGH vmpressure event to occur, assert a pressure state
in the socket and tcp memory code that tells it to curb consumption
growth from sockets associated with said control group.
Traditionally, vmpressure reports for the entire subtree of a memcg
under pressure, which drops useful information on the individual groups
reclaimed. However, it's too late to change the userinterface, so add a
second reporting mode that reports on the level of reclaim instead of at
the level of pressure, and use that report for sockets.
vmpressure events are naturally edge triggered, so for hysteresis assert
socket pressure for a second to allow for subsequent vmpressure events
to occur before letting the socket code return to normal.
This will likely need finetuning for a wider variety of workloads, but
for now stick to the vmpressure presets and keep hysteresis simple.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:21:29 +0000 (15:21 -0800)]
mm: memcontrol: account socket memory in unified hierarchy memory controller
Socket memory can be a significant share of overall memory consumed by
common workloads. In order to provide reasonable resource isolation in
the unified hierarchy, this type of memory needs to be included in the
tracking/accounting of a cgroup under active memory resource control.
Overhead is only incurred when a non-root control group is created AND
the memory controller is instructed to track and account the memory
footprint of that group. cgroup.memory=nosocket can be specified on the
boot commandline to override any runtime configuration and forcibly
exclude socket memory from active memory resource control.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> 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>
Johannes Weiner [Thu, 14 Jan 2016 23:21:26 +0000 (15:21 -0800)]
mm: memcontrol: move socket code for unified hierarchy accounting
The unified hierarchy memory controller will account socket memory.
Move the infrastructure functions accordingly.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:21:23 +0000 (15:21 -0800)]
mm: memcontrol: do not account memory+swap on unified hierarchy
The unified hierarchy memory controller doesn't expose the memory+swap
counter to userspace, but its accounting is hardcoded in all charge
paths right now, including the per-cpu charge cache ("the stock").
To avoid adding yet more pointless memory+swap accounting with the
socket memory support in unified hierarchy, disable the counter
altogether when in unified hierarchy mode.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:21:20 +0000 (15:21 -0800)]
mm: memcontrol: generalize the socket accounting jump label
The unified hierarchy memory controller is going to use this jump label
as well to control the networking callbacks. Move it to the memory
controller code and give it a more generic name.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:21:17 +0000 (15:21 -0800)]
net: tcp_memcontrol: simplify linkage between socket and page counter
There won't be any separate counters for socket memory consumed by
protocols other than TCP in the future. Remove the indirection and link
sockets directly to their owning memory cgroup.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There won't be a tcp control soft limit, so integrating the memcg code
into the global skmem limiting scheme complicates things unnecessarily.
Replace this with simple and clear charge and uncharge calls--hidden
behind a jump label--to account skb memory.
Note that this is not purely aesthetic: as a result of shoehorning the
per-memcg code into the same memory accounting functions that handle the
global level, the old code would compare the per-memcg consumption
against the smaller of the per-memcg limit and the global limit. This
allowed the total consumption of multiple sockets to exceed the global
limit, as long as the individual sockets stayed within bounds. After
this change, the code will always compare the per-memcg consumption to
the per-memcg limit, and the global consumption to the global limit, and
thus close this loophole.
Without a soft limit, the per-memcg memory pressure state in sockets is
generally questionable. However, we did it until now, so we continue to
enter it when the hard limit is hit, and packets are dropped, to let
other sockets in the cgroup know that they shouldn't grow their transmit
windows, either. However, keep it simple in the new callback model and
leave memory pressure lazily when the next packet is accepted (as
opposed to doing it synchroneously when packets are processed). When
packets are dropped, network performance will already be in the toilet,
so that should be a reasonable trade-off.
As described above, consumption is now checked on the per-memcg level
and the global level separately. Likewise, memory pressure states are
maintained on both the per-memcg level and the global level, and a
socket is considered under pressure when either level asserts as much.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:21:11 +0000 (15:21 -0800)]
net: tcp_memcontrol: simplify the per-memcg limit access
tcp_memcontrol replicates the global sysctl_mem limit array per cgroup,
but it only ever sets these entries to the value of the memory_allocated
page_counter limit. Use the latter directly.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:21:08 +0000 (15:21 -0800)]
net: tcp_memcontrol: remove dead per-memcg count of allocated sockets
The number of allocated sockets is used for calculations in the soft
limit phase, where packets are accepted but the socket is under memory
pressure.
Since there is no soft limit phase in tcp_memcontrol, and memory
pressure is only entered when packets are already dropped, this is
actually dead code. Remove it.
As this is the last user of parent_cg_proto(), remove that too.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:21:05 +0000 (15:21 -0800)]
net: tcp_memcontrol: protect all tcp_memcontrol calls by jump-label
Move the jump-label from sock_update_memcg() and sock_release_memcg() to
the callsite, and so eliminate those function calls when socket
accounting is not enabled.
This also eliminates the need for dummy functions because the calls will
be optimized away if the Kconfig options are not enabled.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a cgroup currently breaches its socket memory limit, it enters
memory pressure mode for itself and its *ancestors*. This throttles
transmission in unrelated sibling and cousin subtrees that have nothing
to do with the breached limit.
On the contrary, breaching a limit should make that group and its
*children* enter memory pressure mode. But this happens already, albeit
lazily: if an ancestor limit is breached, siblings will enter memory
pressure on their own once the next packet arrives for them.
So no additional hierarchy code is needed. Remove the bogus stuff.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When charging socket memory, the code currently checks only the local
page counter for excess to determine whether the memcg is under socket
pressure. But even if the local counter is fine, one of the ancestors
could have breached its limit, which should also force this child to
enter socket pressure. This currently doesn't happen.
Fix this by using page_counter_try_charge() first. If that fails, it
means that either the local counter or one of the ancestors are in
excess of their limit, and the child should enter socket pressure.
Fixes: 3e32cb2e0a12 ("mm: memcontrol: lockless page counters") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:20:56 +0000 (15:20 -0800)]
mm: memcontrol: export root_mem_cgroup
A later patch will need this symbol in files other than memcontrol.c, so
export it now and replace mem_cgroup_root_css at the same time.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joonsoo Kim [Thu, 14 Jan 2016 23:20:48 +0000 (15:20 -0800)]
mm/compaction.c: __compact_pgdat() code cleanuup
This patch uses is_via_compact_memory() to distinguish compaction from
sysfs or sysctl. And, this patch also reduces indentation on
compaction_defer_reset() by filtering these cases first before checking
watermark.
There is no functional change.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We already have the for_each_memblock() macro in <linux/memblock.h>
which provides ability to iterate over memblock regions of a known type.
The for_each_memblock() macro allows us to pass the pointer to the
struct memblock_type, instead we need to pass name of the type.
This patch introduces a new macro for_each_memblock_type() which allows
us iterate over memblock regions with the given type when the type is
unknown.
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove rgnbase and rgnsize variables from memblock_overlaps_region().
We use these variables only for passing to the memblock_addrs_overlap()
function and that's all. Let's remove them.
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 14 Jan 2016 23:20:36 +0000 (15:20 -0800)]
mm, oom: give __GFP_NOFAIL allocations access to memory reserves
__GFP_NOFAIL is a big hammer used to ensure that the allocation request
can never fail. This is a strong requirement and as such it also
deserves a special treatment when the system is OOM. The primary
problem here is that the allocation request might have come with some
locks held and the oom victim might be blocked on the same locks. This
is basically an OOM deadlock situation.
This patch tries to reduce the risk of such a deadlocks by giving
__GFP_NOFAIL allocations a special treatment and let them dive into
memory reserves after oom killer invocation. This should help them to
make a progress and release resources they are holding. The OOM victim
should compensate for the reserves consumption.
Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 14 Jan 2016 23:20:28 +0000 (15:20 -0800)]
mm/page_alloc.c: remove unnecessary parameter from __rmqueue
Commit 0aaa29a56e4f ("mm, page_alloc: reserve pageblocks for high-order
atomic allocations on demand") added an unnecessary and unused parameter
to __rmqueue. It was a parameter that was used in an earlier version of
the patch and then left behind. This patch cleans it up.
Seth Jennings [Thu, 14 Jan 2016 23:20:21 +0000 (15:20 -0800)]
drivers/base/memory.c: clean up section counting
Right now, section_count is calculated in add_memory_block(). However,
init_memory_block() increments section_count as well, which, at first,
seems like it would lead to an off-by-one error. There is no harm done
because add_memory_block() immediately overwrites the
mem->section_count, but it is messy.
This commit moves the increment out of the common init_memory_block()
(called by both add_memory_block() and register_new_memory()) and adds
it to register_new_memory().
Signed-off-by: Seth Jennings <sjennings@variantweb.net> Cc: Andrew Banman <abanman@sgi.com> Cc: Daniel J Blueman <daniel@numascale.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Greg KH <greg@kroah.com> Cc: Russ Anderson <rja@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 14 Jan 2016 23:20:18 +0000 (15:20 -0800)]
proc: meminfo: estimate available memory more conservatively
The MemAvailable item in /proc/meminfo is to give users a hint of how
much memory is allocatable without causing swapping, so it excludes the
zones' low watermarks as unavailable to userspace.
However, for a userspace allocation, kswapd will actually reclaim until
the free pages hit a combination of the high watermark and the page
allocator's lowmem protection that keeps a certain amount of DMA and
DMA32 memory from userspace as well.
Subtract the full amount we know to be unavailable to userspace from the
number of free pages when calculating MemAvailable.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> 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>
Johannes Weiner [Thu, 14 Jan 2016 23:20:15 +0000 (15:20 -0800)]
mm: page_alloc: generalize the dirty balance reserve
The dirty balance reserve that dirty throttling has to consider is
merely memory not available to userspace allocations. There is nothing
writeback-specific about it. Generalize the name so that it's reusable
outside of that context.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> 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>
Michal Hocko [Thu, 14 Jan 2016 23:20:12 +0000 (15:20 -0800)]
mm: allow GFP_{FS,IO} for page_cache_read page cache allocation
page_cache_read has been historically using page_cache_alloc_cold to
allocate a new page. This means that mapping_gfp_mask is used as the
base for the gfp_mask. Many filesystems are setting this mask to
GFP_NOFS to prevent from fs recursion issues. page_cache_read is called
from the vm_operations_struct::fault() context during the page fault.
This context doesn't need the reclaim protection normally.
ceph and ocfs2 which call filemap_fault from their fault handlers seem
to be OK because they are not taking any fs lock before invoking generic
implementation. xfs which takes XFS_MMAPLOCK_SHARED is safe from the
reclaim recursion POV because this lock serializes truncate and punch
hole with the page faults and it doesn't get involved in the reclaim.
There is simply no reason to deliberately use a weaker allocation
context when a __GFP_FS | __GFP_IO can be used. The GFP_NOFS protection
might be even harmful. There is a push to fail GFP_NOFS allocations
rather than loop within allocator indefinitely with a very limited
reclaim ability. Once we start failing those requests the OOM killer
might be triggered prematurely because the page cache allocation failure
is propagated up the page fault path and end up in
pagefault_out_of_memory.
We cannot play with mapping_gfp_mask directly because that would be racy
wrt. parallel page faults and it might interfere with other users who
really rely on NOFS semantic from the stored gfp_mask. The mask is also
inode proper so it would even be a layering violation. What we can do
instead is to push the gfp_mask into struct vm_fault and allow fs layer
to overwrite it should the callback need to be called with a different
allocation context.
Initialize the default to (mapping_gfp_mask | __GFP_FS | __GFP_IO)
because this should be safe from the page fault path normally. Why do
we care about mapping_gfp_mask at all then? Because this doesn't hold
only reclaim protection flags but it also might contain zone and
movability restrictions (GFP_DMA32, __GFP_MOVABLE and others) so we have
to respect those.
Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Jan Kara <jack@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Mel Gorman <mgorman@suse.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yaowei Bai [Thu, 14 Jan 2016 23:20:09 +0000 (15:20 -0800)]
mm/compaction: improve comment for compact_memory tunable knob handler
sysctl_compaction_handler() is the handler function for compact_memory
tunable knob under /proc/sys/vm, add the missing knob name to make this
more accurate in comment.
No functional change.
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Cashman [Thu, 14 Jan 2016 23:20:06 +0000 (15:20 -0800)]
x86: mm: support ARCH_MMAP_RND_BITS
x86: arch_mmap_rnd() uses hard-coded values, 8 for 32-bit and 28 for
64-bit, to generate the random offset for the mmap base address. This
value represents a compromise between increased ASLR effectiveness and
avoiding address-space fragmentation. Replace it with a Kconfig option,
which is sensibly bounded, so that platform developers may choose where
to place this compromise. Keep default values as new minimums.
Signed-off-by: Daniel Cashman <dcashman@google.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Don Zickus <dzickus@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Rientjes <rientjes@google.com> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Nick Kralevich <nnk@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Borislav Petkov <bp@suse.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Cashman [Thu, 14 Jan 2016 23:20:01 +0000 (15:20 -0800)]
arm64: mm: support ARCH_MMAP_RND_BITS
arm64: arch_mmap_rnd() uses STACK_RND_MASK to generate the random offset
for the mmap base address. This value represents a compromise between
increased ASLR effectiveness and avoiding address-space fragmentation.
Replace it with a Kconfig option, which is sensibly bounded, so that
platform developers may choose where to place this compromise. Keep
default values as new minimums.
Signed-off-by: Daniel Cashman <dcashman@google.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Don Zickus <dzickus@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Rientjes <rientjes@google.com> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Nick Kralevich <nnk@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Borislav Petkov <bp@suse.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Cashman [Thu, 14 Jan 2016 23:19:57 +0000 (15:19 -0800)]
arm: mm: support ARCH_MMAP_RND_BITS
arm: arch_mmap_rnd() uses a hard-code value of 8 to generate the random
offset for the mmap base address. This value represents a compromise
between increased ASLR effectiveness and avoiding address-space
fragmentation. Replace it with a Kconfig option, which is sensibly
bounded, so that platform developers may choose where to place this
compromise. Keep 8 as the minimum acceptable value.
[arnd@arndb.de: ARM: avoid ARCH_MMAP_RND_BITS for NOMMU] Signed-off-by: Daniel Cashman <dcashman@google.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Don Zickus <dzickus@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Rientjes <rientjes@google.com> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Nick Kralevich <nnk@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Borislav Petkov <bp@suse.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Cashman [Thu, 14 Jan 2016 23:19:53 +0000 (15:19 -0800)]
mm: mmap: add new /proc tunable for mmap_base ASLR
Address Space Layout Randomization (ASLR) provides a barrier to
exploitation of user-space processes in the presence of security
vulnerabilities by making it more difficult to find desired code/data
which could help an attack. This is done by adding a random offset to
the location of regions in the process address space, with a greater
range of potential offset values corresponding to better protection/a
larger search-space for brute force, but also to greater potential for
fragmentation.
The offset added to the mmap_base address, which provides the basis for
the majority of the mappings for a process, is set once on process exec
in arch_pick_mmap_layout() and is done via hard-coded per-arch values,
which reflect, hopefully, the best compromise for all systems. The
trade-off between increased entropy in the offset value generation and
the corresponding increased variability in address space fragmentation
is not absolute, however, and some platforms may tolerate higher amounts
of entropy. This patch introduces both new Kconfig values and a sysctl
interface which may be used to change the amount of entropy used for
offset generation on a system.
The direct motivation for this change was in response to the
libstagefright vulnerabilities that affected Android, specifically to
information provided by Google's project zero at:
The attack presented therein, by Google's project zero, specifically
targeted the limited randomness used to generate the offset added to the
mmap_base address in order to craft a brute-force-based attack.
Concretely, the attack was against the mediaserver process, which was
limited to respawning every 5 seconds, on an arm device. The hard-coded
8 bits used resulted in an average expected success rate of defeating
the mmap ASLR after just over 10 minutes (128 tries at 5 seconds a
piece). With this patch, and an accompanying increase in the entropy
value to 16 bits, the same attack would take an average expected time of
over 45 hours (32768 tries), which makes it both less feasible and more
likely to be noticed.
The introduced Kconfig and sysctl options are limited by per-arch
minimum and maximum values, the minimum of which was chosen to match the
current hard-coded value and the maximum of which was chosen so as to
give the greatest flexibility without generating an invalid mmap_base
address, generally a 3-4 bits less than the number of bits in the
user-space accessible virtual address space.
When decided whether or not to change the default value, a system
developer should consider that mmap_base address could be placed
anywhere up to 2^(value) bits away from the non-randomized location,
which would introduce variable-sized areas above and below the mmap_base
address such that the maximum vm_area_struct size may be reduced,
preventing very large allocations.
This patch (of 4):
ASLR only uses as few as 8 bits to generate the random offset for the
mmap base address on 32 bit architectures. This value was chosen to
prevent a poorly chosen value from dividing the address space in such a
way as to prevent large allocations. This may not be an issue on all
platforms. Allow the specification of a minimum number of bits so that
platforms desiring greater ASLR protection may determine where to place
the trade-off.
Signed-off-by: Daniel Cashman <dcashman@google.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Don Zickus <dzickus@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Rientjes <rientjes@google.com> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Nick Kralevich <nnk@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Borislav Petkov <bp@suse.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/mmap.c: remove incorrect MAP_FIXED flag comparison from mmap_region
The following flag comparison in mmap_region makes no sense:
if (!(vm_flags & MAP_FIXED))
return -ENOMEM;
The condition is always false and thus the above "return -ENOMEM" is
never executed. The vm_flags must not be compared with MAP_FIXED flag.
The vm_flags may only be compared with VM_* flags. MAP_FIXED has the
same value as VM_MAYREAD.
Hitting the rlimit is a slow path and find_vma_intersection should
realize that there is no overlapping VMA for !MAP_FIXED case pretty
quickly.
Signed-off-by: Piotr Kwapulinski <kwapulinski.piotr@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 14 Jan 2016 23:19:47 +0000 (15:19 -0800)]
mm, vmscan: consider isolated pages in zone_reclaimable_pages
zone_reclaimable_pages counts how many pages are reclaimable in the
given zone. This currently includes all pages on file lrus and anon
lrus if there is an available swap storage. We do not consider
NR_ISOLATED_{ANON,FILE} counters though which is not correct because
these counters reflect temporarily isolated pages which are still
reclaimable because they either get back to their LRU or get freed
either by the page reclaim or page migration.
The number of these pages might be sufficiently high to confuse users of
zone_reclaimable_pages (e.g. mbind can migrate large ranges of memory
at once).
Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vladimir Davydov [Thu, 14 Jan 2016 23:19:41 +0000 (15:19 -0800)]
memcg: do not allow to disable tcp accounting after limit is set
There are two bits defined for cg_proto->flags - MEMCG_SOCK_ACTIVATED
and MEMCG_SOCK_ACTIVE - both are set in tcp_update_limit, but the former
is never cleared while the latter can be cleared by unsetting the limit.
This allows to disable tcp socket accounting for new sockets after it
was enabled by writing -1 to memory.kmem.tcp.limit_in_bytes while still
guaranteeing that memcg_socket_limit_enabled static key will be
decremented on memcg destruction.
This functionality looks dubious, because it is not clear what a use
case would be. By enabling tcp accounting a user accepts the price. If
they then find the performance degradation unacceptable, they can always
restart their workload with tcp accounting disabled. It does not seem
there is any need to flip it while the workload is running.
Besides, it contradicts to how kmem accounting API works: writing
whatever to memory.kmem.limit_in_bytes enables kmem accounting for the
cgroup in question, after which it cannot be disabled. Therefore one
might expect that writing -1 to memory.kmem.tcp.limit_in_bytes just
enables socket accounting w/o limiting it, which might be useful by
itself, but it isn't true.
Since this API peculiarity is not documented anywhere, I propose to drop
it. This will allow to simplify the code by dropping cg_proto->flags.
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vladimir Davydov [Thu, 14 Jan 2016 23:19:38 +0000 (15:19 -0800)]
vmscan: do not force-scan file lru if its absolute size is small
We assume there is enough inactive page cache if the size of inactive
file lru is greater than the size of active file lru, in which case we
force-scan file lru ignoring anonymous pages. While this logic works
fine when there are plenty of page cache pages, it fails if the size of
file lru is small (several MB): in this case (lru_size >> prio) will be
0 for normal scan priorities, as a result, if inactive file lru happens
to be larger than active file lru, anonymous pages of a cgroup will
never get evicted unless the system experiences severe memory pressure,
even if there are gigabytes of unused anonymous memory there, which is
unfair in respect to other cgroups, whose workloads might be page cache
oriented.
This patch attempts to fix this by elaborating the "enough inactive page
cache" check: it makes it not only check that inactive lru size > active
lru size, but also that we will scan something from the cgroup at the
current scan priority. If these conditions do not hold, we proceed to
SCAN_FRACT as usual.
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jerome Marchand [Thu, 14 Jan 2016 23:19:29 +0000 (15:19 -0800)]
mm, procfs: breakdown RSS for anon, shmem and file in /proc/pid/status
There are several shortcomings with the accounting of shared memory
(SysV shm, shared anonymous mapping, mapping of a tmpfs file). The
values in /proc/<pid>/status and <...>/statm don't allow to distinguish
between shmem memory and a shared mapping to a regular file, even though
theirs implication on memory usage are quite different: during reclaim,
file mapping can be dropped or written back on disk, while shmem needs a
place in swap.
Also, to distinguish the memory occupied by anonymous and file mappings,
one has to read the /proc/pid/statm file, which has a field for the file
mappings (again, including shmem) and total memory occupied by these
mappings (i.e. equivalent to VmRSS in the <...>/status file. Getting
the value for anonymous mappings only is thus not exactly user-friendly
(the statm file is intended to be rather efficiently machine-readable).
To address both of these shortcomings, this patch adds a breakdown of
VmRSS in /proc/<pid>/status via new fields RssAnon, RssFile and
RssShmem, making use of the previous preparatory patch. These fields
tell the user the memory occupied by private anonymous pages, mapped
regular files and shmem, respectively. Other existing fields in /status
and /statm files are left without change. The /statm file can be
extended in the future, if there's a need for that.
Example (part of) /proc/pid/status output including the new Rss* fields:
Jerome Marchand [Thu, 14 Jan 2016 23:19:26 +0000 (15:19 -0800)]
mm, shmem: add internal shmem resident memory accounting
Currently looking at /proc/<pid>/status or statm, there is no way to
distinguish shmem pages from pages mapped to a regular file (shmem pages
are mapped to /dev/zero), even though their implication in actual memory
use is quite different.
The internal accounting currently counts shmem pages together with
regular files. As a preparation to extend the userspace interfaces,
this patch adds MM_SHMEMPAGES counter to mm_rss_stat to account for
shmem pages separately from MM_FILEPAGES. The next patch will expose it
to userspace - this patch doesn't change the exported values yet, by
adding up MM_SHMEMPAGES to MM_FILEPAGES at places where MM_FILEPAGES was
used before. The only user-visible change after this patch is the OOM
killer message that separates the reported "shmem-rss" from "file-rss".
Vlastimil Babka [Thu, 14 Jan 2016 23:19:23 +0000 (15:19 -0800)]
mm, proc: reduce cost of /proc/pid/smaps for unpopulated shmem mappings
Following the previous patch, further reduction of /proc/pid/smaps cost
is possible for private writable shmem mappings with unpopulated areas
where the page walk invokes the .pte_hole function. We can use radix
tree iterator for each such area instead of calling find_get_entry() in
a loop. This is possible at the extra maintenance cost of introducing
another shmem function shmem_partial_swap_usage().
To demonstrate the diference, I have measured this on a process that
creates a private writable 2GB mapping of a partially swapped out
/dev/shm/file (which cannot employ the optimizations from the prvious
patch) and doesn't populate it at all. I time how long does it take to
cat /proc/pid/smaps of this process 100 times.
Before this patch:
real 0m3.831s
user 0m0.180s
sys 0m3.212s
After this patch:
real 0m1.176s
user 0m0.180s
sys 0m0.684s
The time is similar to the case where a radix tree iterator is employed
on the whole mapping.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> 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>
Vlastimil Babka [Thu, 14 Jan 2016 23:19:20 +0000 (15:19 -0800)]
mm, proc: reduce cost of /proc/pid/smaps for shmem mappings
The previous patch has improved swap accounting for shmem mapping, which
however made /proc/pid/smaps more expensive for shmem mappings, as we
consult the radix tree for each pte_none entry, so the overal complexity
is O(n*log(n)).
We can reduce this significantly for mappings that cannot contain COWed
pages, because then we can either use the statistics tha shmem object
itself tracks (if the mapping contains the whole object, or the swap
usage of the whole object is zero), or use the radix tree iterator,
which is much more effective than repeated find_get_entry() calls.
This patch therefore introduces a function shmem_swap_usage(vma) and
makes /proc/pid/smaps use it when possible. Only for writable private
mappings of shmem objects (i.e. tmpfs files) with the shmem object
itself (partially) swapped outwe have to resort to the find_get_entry()
approach.
Hopefully such mappings are relatively uncommon.
To demonstrate the diference, I have measured this on a process that
creates a 2GB mapping and dirties single pages with a stride of 2MB, and
time how long does it take to cat /proc/pid/smaps of this process 100
times.
Private writable mapping of a /dev/shm/file (the most complex case):
real 0m3.831s
user 0m0.180s
sys 0m3.212s
Shared mapping of an almost full mapping of a partially swapped /dev/shm/file
(which needs to employ the radix tree iterator).
real 0m1.351s
user 0m0.096s
sys 0m0.768s
Same, but with /dev/shm/file not swapped (so no radix tree walk needed)
real 0m0.935s
user 0m0.128s
sys 0m0.344s
Private anonymous mapping:
real 0m0.949s
user 0m0.116s
sys 0m0.348s
The cost is now much closer to the private anonymous mapping case, unless
the shmem mapping is private and writable.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> 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>
Vlastimil Babka [Thu, 14 Jan 2016 23:19:17 +0000 (15:19 -0800)]
mm, proc: account for shmem swap in /proc/pid/smaps
Currently, /proc/pid/smaps will always show "Swap: 0 kB" for
shmem-backed mappings, even if the mapped portion does contain pages
that were swapped out. This is because unlike private anonymous
mappings, shmem does not change pte to swap entry, but pte_none when
swapping the page out. In the smaps page walk, such page thus looks
like it was never faulted in.
This patch changes smaps_pte_entry() to determine the swap status for
such pte_none entries for shmem mappings, similarly to how
mincore_page() does it. Swapped out shmem pages are thus accounted for.
For private mappings of tmpfs files that COWed some of the pages, swaped
out status of the original shmem pages is naturally ignored. If some of
the private copies was also swapped out, they are accounted via their
page table swap entries, so the resulting reported swap usage is then a
sum of both swapped out private copies, and swapped out shmem pages that
were not COWed. No double accounting can thus happen.
The accounting is arguably still not as precise as for private anonymous
mappings, since now we will count also pages that the process in
question never accessed, but another process populated them and then let
them become swapped out. I believe it is still less confusing and
subtle than not showing any swap usage by shmem mappings at all.
Swapped out counter might of interest of users who would like to prevent
from future swapins during performance critical operation and pre-fault
them at their convenience. Especially for larger swapped out regions
the cost of swapin is much higher than a fresh page allocation. So a
differentiation between pte_none vs. swapped out is important for those
usecases.
One downside of this patch is that it makes /proc/pid/smaps more
expensive for shmem mappings, as we consult the radix tree for each
pte_none entry, so the overal complexity is O(n*log(n)). I have
measured this on a process that creates a 2GB mapping and dirties single
pages with a stride of 2MB, and time how long does it take to cat
/proc/pid/smaps of this process 100 times.
Private anonymous mapping:
real 0m0.949s
user 0m0.116s
sys 0m0.348s
Mapping of a /dev/shm/file:
real 0m3.831s
user 0m0.180s
sys 0m3.212s
The difference is rather substantial, so the next patch will reduce the
cost for shared or read-only mappings.
In a less controlled experiment, I've gathered pids of processes on my
desktop that have either '/dev/shm/*' or 'SYSV*' in smaps. This
included the Chrome browser and some KDE processes. Again, I've run cat
/proc/pid/smaps on each 100 times.
Before this patch:
real 0m9.050s
user 0m0.518s
sys 0m8.066s
After this patch:
real 0m9.221s
user 0m0.541s
sys 0m8.187s
This suggests low impact on average systems.
Note that this patch doesn't attempt to adjust the SwapPss field for
shmem mappings, which would need extra work to determine who else could
have the pages mapped. Thus the value stays zero except for COWed
swapped out pages in a shmem mapping, which are accounted as usual.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Thu, 14 Jan 2016 23:19:14 +0000 (15:19 -0800)]
mm, documentation: clarify /proc/pid/status VmSwap limitations for shmem
This series is based on Jerome Marchand's [1] so let me quote the first
paragraph from there:
There are several shortcomings with the accounting of shared memory
(sysV shm, shared anonymous mapping, mapping to a tmpfs file). The
values in /proc/<pid>/status and statm don't allow to distinguish
between shmem memory and a shared mapping to a regular file, even though
their implications on memory usage are quite different: at reclaim, file
mapping can be dropped or written back on disk while shmem needs a place
in swap. As for shmem pages that are swapped-out or in swap cache, they
aren't accounted at all.
The original motivation for myself is that a customer found (IMHO
rightfully) confusing that e.g. top output for process swap usage is
unreliable with respect to swapped out shmem pages, which are not
accounted for.
The fundamental difference between private anonymous and shmem pages is
that the latter has PTE's converted to pte_none, and not swapents. As
such, they are not accounted to the number of swapents visible e.g. in
/proc/pid/status VmSwap row. It might be theoretically possible to use
swapents when swapping out shmem (without extra cost, as one has to
change all mappers anyway), and on swap in only convert the swapent for
the faulting process, leaving swapents in other processes until they
also fault (so again no extra cost). But I don't know how many
assumptions this would break, and it would be too disruptive change for
a relatively small benefit.
Instead, my approach is to document the limitation of VmSwap, and
provide means to determine the swap usage for shmem areas for those who
are interested and willing to pay the price, using /proc/pid/smaps.
Because outside of ipcs, I don't think it's possible to currently to
determine the usage at all. The previous patchset [1] did introduce new
shmem-specific fields into smaps output, and functions to determine the
values. I take a simpler approach, noting that smaps output already has
a "Swap: X kB" line, where currently X == 0 always for shmem areas. I
think we can just consider this a bug and provide the proper value by
consulting the radix tree, as e.g. mincore_page() does. In the patch
changelog I explain why this is also not perfect (and cannot be without
swapents), but still arguably much better than showing a 0.
The last two patches are adapted from Jerome's patchset and provide a
VmRSS breakdown to RssAnon, RssFile and RssShm in /proc/pid/status.
Hugh noted that this is a welcome addition, and I agree that it might
help e.g. debugging process memory usage at albeit non-zero, but still
rather low cost of extra per-mm counter and some page flag checks.
[1] http://lwn.net/Articles/611966/
This patch (of 6):
The documentation for /proc/pid/status does not mention that the value
of VmSwap counts only swapped out anonymous private pages, and not
swapped out pages of the underlying shmem objects (for shmem mappings).
This is not obvious, so document this limitation.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 14 Jan 2016 23:19:05 +0000 (15:19 -0800)]
mm/page_alloc.c: do not loop over ALLOC_NO_WATERMARKS without triggering reclaim
__alloc_pages_slowpath is looping over ALLOC_NO_WATERMARKS requests if
__GFP_NOFAIL is requested. This is fragile because we are basically
relying on somebody else to make the reclaim (be it the direct reclaim
or OOM killer) for us. The caller might be holding resources (e.g.
locks) which block other other reclaimers from making any progress for
example. Remove the retry loop and rely on __alloc_pages_slowpath to
invoke all allowed reclaim steps and retry logic.
We have to be careful about __GFP_NOFAIL allocations from the
PF_MEMALLOC context even though this is a very bad idea to begin with
because no progress can be gurateed at all. We shouldn't break the
__GFP_NOFAIL semantic here though. It could be argued that this is
essentially GFP_NOWAIT context which we do not support but PF_MEMALLOC
is much harder to check for existing users because they might happen
deep down the code path performed much later after setting the flag so
we cannot really rule out there is no kernel path triggering this
combination.
Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: David Rientjes <rientjes@google.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 14 Jan 2016 23:19:03 +0000 (15:19 -0800)]
mm/page_alloc.c: get rid of __alloc_pages_high_priority()
__alloc_pages_high_priority doesn't do anything special other than it
calls get_page_from_freelist and loops around GFP_NOFAIL allocation
until it succeeds. It would be better if the first part was done in
__alloc_pages_slowpath where we modify the zonelist because this would
be easier to read and understand. Opencoding the function into its only
caller allows to simplify it a bit as well.
This patch doesn't introduce any functional changes.
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit a0b8cab3b9b2 ("mm: remove lru parameter from
__pagevec_lru_add and remove parts of pagevec API") there's no
user of this function anymore, so remove it.
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yaowei Bai [Thu, 14 Jan 2016 23:18:54 +0000 (15:18 -0800)]
mm/memblock.c: memblock_is_memory()/reserved() can be boolean
Make memblock_is_memory() and memblock_is_reserved return bool to
improve readability due to these particular functions only using either
one or zero as their return value.
No functional change.
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> 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>
yalin wang [Thu, 14 Jan 2016 23:18:48 +0000 (15:18 -0800)]
mm: change mm_vmscan_lru_shrink_inactive() proto types
Move node_id zone_idx shrink flags into trace function, so thay we don't
need caculate these args if the trace is disabled, and will make this
function have less arguments.
Signed-off-by: yalin wang <yalin.wang2010@gmail.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joonsoo Kim [Thu, 14 Jan 2016 23:18:45 +0000 (15:18 -0800)]
mm/cma: always check which page caused allocation failure
Now, we have tracepoint in test_pages_isolated() to notify pfn which
cannot be isolated. But, in alloc_contig_range(), some error path
doesn't call test_pages_isolated() so it's still hard to know exact pfn
that causes allocation failure.
This patch change this situation by calling test_pages_isolated() in
almost error path. In allocation failure case, some overhead is added
by this change, but, allocation failure is really rare event so it would
not matter.
In fatal signal pending case, we don't call test_pages_isolated()
because this failure is intentional one.
There was a bogus outer_start problem due to unchecked buddy order and
this patch also fix it. Before this patch, it didn't matter, because
end result is same thing. But, after this patch, tracepoint will report
failed pfn so it should be accurate.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: David Rientjes <rientjes@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joonsoo Kim [Thu, 14 Jan 2016 23:18:42 +0000 (15:18 -0800)]
mm/page_isolation.c: add new tracepoint, test_pages_isolated
cma allocation should be guranteeded to succeed. But sometimes it can
fail in the current implementation. To track down the problem, we need
to know which page is problematic and this new tracepoint will report
it.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joonsoo Kim [Thu, 14 Jan 2016 23:18:39 +0000 (15:18 -0800)]
mm/page_isolation.c: return last tested pfn rather than failure indicator
This is preparation step to report test failed pfn in new tracepoint to
analyze cma allocation failure problem. There is no functional change
in this patch.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nathan Zimmer [Thu, 14 Jan 2016 23:18:36 +0000 (15:18 -0800)]
mm/mempolicy.c: convert the shared_policy lock to a rwlock
When running the SPECint_rate gcc on some very large boxes it was
noticed that the system was spending lots of time in
mpol_shared_policy_lookup(). The gamess benchmark can also show it and
is what I mostly used to chase down the issue since the setup for that I
found to be easier.
To be clear the binaries were on tmpfs because of disk I/O requirements.
We then used text replication to avoid icache misses and having all the
copies banging on the memory where the instruction code resides. This
results in us hitting a bottleneck in mpol_shared_policy_lookup() since
lookup is serialised by the shared_policy lock.
I have only reproduced this on very large (3k+ cores) boxes. The
problem starts showing up at just a few hundred ranks getting worse
until it threatens to livelock once it gets large enough. For example
on the gamess benchmark at 128 ranks this area consumes only ~1% of
time, at 512 ranks it consumes nearly 13%, and at 2k ranks it is over
90%.
To alleviate the contention in this area I converted the spinlock to an
rwlock. This allows a large number of lookups to happen simultaneously.
The results were quite good reducing this consumtion at max ranks to
around 2%.
Vladimir Davydov [Thu, 14 Jan 2016 23:18:21 +0000 (15:18 -0800)]
kmemcg: account certain kmem allocations to memcg
Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg. For the list, see below:
- threadinfo
- task_struct
- task_delay_info
- pid
- cred
- mm_struct
- vm_area_struct and vm_region (nommu)
- anon_vma and anon_vma_chain
- signal_struct
- sighand_struct
- fs_struct
- files_struct
- fdtable and fdtable->full_fds_bits
- dentry and external_name
- inode for all filesystems. This is the most tedious part, because
most filesystems overwrite the alloc_inode method.
The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds. Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vladimir Davydov [Thu, 14 Jan 2016 23:18:18 +0000 (15:18 -0800)]
vmalloc: allow to account vmalloc to memcg
Make vmalloc family functions allocate vmalloc area pages with
alloc_kmem_pages so that if __GFP_ACCOUNT is set they will be accounted
to memcg. This is needed, at least, to account alloc_fdmem allocations.
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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