Commit Graph

308895 Commits

Author SHA1 Message Date
Jan-Simon Möller
a58b3a4aba Fix typo in include/linux/clk.h .
Signed-off-by: Jan-Simon Möller <jansimon.moeller@gmx.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-24 13:00:02 +02:00
Masanari Iida
367fa9821a pci: hotplug: Fix typo in pci
Correct spelling typo in drivers/pci/hotplug.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-24 12:59:30 +02:00
Masanari Iida
07db04098d iommu: Fix typo in iommu
Correct spelling typo in debug messages and comments
in drivers/iommu.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-24 12:58:49 +02:00
Masanari Iida
ff0c26424c video: Fix typo in drivers/video
Correct spelling typo in debug messages and comments
within drivers/video.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-24 12:58:15 +02:00
Jesper Juhl
f9028317b2 Documentation: Add newline at end-of-file to files lacking one
This patch simply adds a newline character at end-of-file to those
files in Documentation/ that currently lack one.

This is done for a few different reasons:

A) It's rather annoying when you do "cat some_file.txt" that your
   prompt/cursor ends up at the end of the last line of output rather
   than on a new line.

B) Some tools that process files line-by-line may get confused by the
   lack of a newline on the last line.

C) The "\ No newline at end of file" line in diffs annoys me for some
   reason.

So, let's just add the missing newline once and for all.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-20 23:10:28 +02:00
Geert Uytterhoeven
18d8fe1f89 arm,unicore32: Remove obsolete "select MISC_DEVICES"
Obsoleted since commit 7c5763b845 ("drivers:
misc: Remove MISC_DEVICES config option")

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-20 10:40:35 +02:00
Geert Uytterhoeven
2e76c2838a module.c: spelling s/postition/position/g
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-20 10:38:35 +02:00
Masanari Iida
c03c301374 cpufreq: Fix typo in cpufreq driver
Correct spelling typo in cpufreq driver.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-20 10:37:40 +02:00
Masatake YAMATO
4fec54203f trivial: typo in comment in mksysmap
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-20 10:36:05 +02:00
Masanari Iida
260db90282 mach-omap2: Fix typo in debug message and comment
Correcting spelling typo in mach-omap2

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-20 10:35:24 +02:00
Krzysztof Wilczynski
b631cf1f89 scsi: aha152x: Fix sparse warning and make printing pointer address more portable.
This is to change use of "0x%08x" in favour of "%p" as per ../Documentation/printk-formats.txt,
which also takes care about the following warning during compilation time:

  drivers/scsi/aha152x.c: In function ‘get_command’:
  drivers/scsi/aha152x.c:2987: warning: cast from pointer to integer of different size

Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-20 10:19:25 +02:00
Steve Glendinning
90b24cfb42 Change email address for Steve Glendinning
I no longer have a mailbox at smsc.com, and I've had two reports
that that email address now bounces from people trying to
contact me.  This patch updates all references to that invalid
address to one that I can be contacted on more permanently.

This patch also updates the maintainer status to reflect
the fact I'm no longer directly paid to maintain these drivers.

Signed-off-by: Steve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-17 16:15:38 +02:00
Liu Bo
10983f2e8d Btrfs: fix typo in convert_extent_bit
It should be convert_extent_bit.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-12 11:27:34 +02:00
Alan Cox
39012f6805 via: Remove bogus if check
Reported-by: <dcb314@hotmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Resolves-bug:  https://bugzilla.kernel.org/show_bug.cgi?id=44331
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-11 17:37:24 +02:00
Liu Bo
0f307323a4 netprio_cgroup.c: fix comment typo
poitner -> pointer.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-10 13:14:23 +02:00
Martlin Ettl
9ea3c49896 backlight: fix memory leak on obscure error path
Dredged out of bugzilla

Reported-by: Martlin Ettl <ettl.martin@gmx.de>
Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=15492
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-07-09 16:20:11 +02:00
Jiri Kosina
59f91e5dd0 Merge branch 'master' into for-next
Conflicts:
	include/linux/mmzone.h

Synced with Linus' tree so that trivial patch can be applied
on top of up-to-date code properly.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
2012-06-29 14:45:58 +02:00
Paul Gortmaker
57bdfdd800 Documentation: asus-laptop.txt references an obsolete Kconfig item
The CONFIG_X86_UP_APIC option no longer exists.  Delete the
reference of it.

Cc: trivial@kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-28 12:04:16 +02:00
Christopher L. Simons
692c86b75d Documentation: ManagementStyle: fixed typo
Fixed a spelling error (less that you -> less than you)

Signed-off-by: Christopher L. Simons <christopherleesimons@gmail.com>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-28 12:03:15 +02:00
Wanpeng Li
ab8704b8c6 mm/vmscan: cleanup comment error in balance_pgdat
Signed-off-by: Wanpeng Li <liwp.linux@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-28 11:58:48 +02:00
Wanpeng Li
46028e6d10 mm: cleanup on the comments of zone_reclaim_stat
Signed-off-by: Wanpeng Li <liwp.linux@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-28 11:56:12 +02:00
Wanpeng Li
be7bd59db7 mm: fix page reclaim comment error
Since there are five lists in LRU cache, the array nr in get_scan_count
should be:

nr[0] = anon inactive pages to scan; nr[1] = anon active pages to scan
nr[2] = file inactive pages to scan; nr[3] = file active pages to scan

Signed-off-by: Wanpeng Li <liwp.linux@gmail.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-28 11:54:12 +02:00
Akinobu Mita
422aa27420 lib: correct link to the original source for div64_u64
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jiri Kosina <trivial@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-28 11:51:39 +02:00
Paul Bolle
8b7d133cc2 ab8500-btemp: Fix typo 'AB5500'
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-28 11:48:39 +02:00
Paul Bolle
6ac7d11527 treewide: Put a space between #include and FILE
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-28 11:44:36 +02:00
Alan Cox
954bd6d1c9 lm8333: Fix check ordering
Fix harmless reference off end of array

Reported-by: <dcb314@hotmail.com>
Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?43861
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-27 17:35:55 +02:00
Paul Bolle
c224071e28 parisc: cleanup quoted include
A quoted include starts with a superfluous "./". Clean up that quoted
include.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-05 10:15:58 +02:00
Paul Bolle
cc502bb741 renesas_usbhs: cleanup quoted includes
A few quoted includes start with a superfluous "./". Clean up those
quoted includes.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-05 10:15:25 +02:00
Kazuo Moriwaka
d2582a7afc Doc: document max raw dev number
Documenting description about max minor number of raw devices.

Signed-off-by: Kazuo Moriwaka <moriwaka@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-03 12:05:50 +02:00
Ralf Baechle
92a9f14b8b Fix comment typo multipy -> multiply
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-03 12:04:08 +02:00
Hugh Dickins
89abfab133 mm/memcg: move reclaim_stat into lruvec
With mem_cgroup_disabled() now explicit, it becomes clear that the
zone_reclaim_stat structure actually belongs in lruvec, per-zone when
memcg is disabled but per-memcg per-zone when it's enabled.

We can delete mem_cgroup_get_reclaim_stat(), and change
update_page_reclaim_stat() to update just the one set of stats, the one
which get_scan_count() will actually use.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:25 -07:00
Hugh Dickins
c3c787e8c3 mm/memcg: scanning_global_lru means mem_cgroup_disabled
Although one has to admire the skill with which it has been concealed,
scanning_global_lru(mz) is actually just an interesting way to test
mem_cgroup_disabled().  Too many developer hours have been wasted on
confusing it with global_reclaim(): just use mem_cgroup_disabled().

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Glauber Costa <glommer@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:25 -07:00
Hugh Dickins
86493009d3 memcg swap: use mem_cgroup_uncharge_swap()
That stuff __mem_cgroup_commit_charge_swapin() does with a swap entry, it
has a name and even a declaration: just use mem_cgroup_uncharge_swap().

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
Hugh Dickins
e91cbb4253 memcg swap: mem_cgroup_move_swap_account never needs fixup
The need_fixup arg to mem_cgroup_move_swap_account() is always false,
so just remove it.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
KAMEZAWA Hiroyuki
4b91355e9d memcg: fix/change behavior of shared anon at moving task
This patch changes memcg's behavior at task_move().

At task_move(), the kernel scans a task's page table and move the changes
for mapped pages from source cgroup to target cgroup.  There has been a
bug at handling shared anonymous pages for a long time.

Before patch:
  - The spec says 'shared anonymous pages are not moved.'
  - The implementation was 'shared anonymoys pages may be moved'.
    If page_mapcount <=2, shared anonymous pages's charge were moved.

After patch:
  - The spec says 'all anonymous pages are moved'.
  - The implementation is 'all anonymous pages are moved'.

Considering usage of memcg, this will not affect user's experience.
'shared anonymous' pages only exists between a tree of processes which
don't do exec().  Moving one of process without exec() seems not sane.
For example, libcgroup will not be affected by this change.  (Anyway, no
one noticed the implementation for a long time...)

Below is a discussion log:

 - current spec/implementation are complex
 - Now, shared file caches are moved
 - It adds unclear check as page_mapcount(). To do correct check,
   we should check swap users, etc.
 - No one notice this implementation behavior. So, no one get benefit
   from the design.
 - In general, once task is moved to a cgroup for running, it will not
   be moved....
 - Finally, we have control knob as memory.move_charge_at_immigrate.

Here is a patch to allow moving shared pages, completely. This makes
memcg simpler and fix current broken code.

Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
Gavin Shan
181eb39425 mm/memblock: fix memory leak on extending regions
The overall memblock has been organized into the memory regions and
reserved regions.  Initially, the memory regions and reserved regions are
stored in the predetermined arrays of "struct memblock _region".  It's
possible for the arrays to be enlarged when we have newly added regions,
but no free space left there.  The policy here is to create double-sized
array either by slab allocator or memblock allocator.  Unfortunately, we
didn't free the old array, which might be allocated through slab allocator
before.  That would cause memory leak.

The patch introduces 2 variables to trace where (slab or memblock) the
memory and reserved regions come from.  The memory for the memory or
reserved regions will be deallocated by kfree() if that was allocated by
slab allocator.  Thus to fix the memory leak issue.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
Gavin Shan
4e2f07750d mm/memblock: cleanup on duplicate VA/PA conversion
The overall memblock has been organized into the memory regions and
reserved regions.  Initially, the memory regions and reserved regions are
stored in the predetermined arrays of "struct memblock _region".  It's
possible for the arrays to be enlarged when we have newly added regions
for them, but no enough space there.  Under the situation, We will created
double-sized array to meet the requirement.  However, the original
implementation converted the VA (Virtual Address) of the newly allocated
array of regions to PA (Physical Address), then translate back when we
allocates the new array from slab.  That's actually unnecessary.

The patch removes the duplicate VA/PA conversion.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
Pravin B Shelar
5bf5f03c27 mm: fix slab->page flags corruption
Transparent huge pages can change page->flags (PG_compound_lock) without
taking Slab lock.  Since THP can not break slab pages we can safely access
compound page without taking compound lock.

Specifically this patch fixes a race between compound_unlock() and slab
functions which perform page-flags updates.  This can occur when
get_page()/put_page() is called on a page from slab.

[akpm@linux-foundation.org: tweak comment text, fix comment layout, fix label indenting]
Reported-by: Amey Bhide <abhide@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
KyongHo
dbda591d92 mm: fix faulty initialization in vmalloc_init()
The transfer of ->flags causes some of the static mapping virtual
addresses to be prematurely freed (before the mapping is removed) because
VM_LAZY_FREE gets "set" if tmp->flags has VM_IOREMAP set.  This might
cause subsequent vmalloc/ioremap calls to fail because it might allocate
one of the freed virtual address ranges that aren't unmapped.

va->flags has different types of flags from tmp->flags.  If a region with
VM_IOREMAP set is registered with vm_area_add_early(), it will be removed
by __purge_vmap_area_lazy().

Fix vmalloc_init() to correctly initialize vmap_area for the given
vm_struct.

Also initialise va->vm.  If it is not set, find_vm_area() for the early
vm regions will always fail.

Signed-off-by: KyongHo Cho <pullip.cho@samsung.com>
Cc: "Olav Haugan" <ohaugan@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
Andrea Arcangeli
26c191788f mm: pmd_read_atomic: fix 32bit PAE pmd walk vs pmd_populate SMP race condition
When holding the mmap_sem for reading, pmd_offset_map_lock should only
run on a pmd_t that has been read atomically from the pmdp pointer,
otherwise we may read only half of it leading to this crash.

PID: 11679  TASK: f06e8000  CPU: 3   COMMAND: "do_race_2_panic"
 #0 [f06a9dd8] crash_kexec at c049b5ec
 #1 [f06a9e2c] oops_end at c083d1c2
 #2 [f06a9e40] no_context at c0433ded
 #3 [f06a9e64] bad_area_nosemaphore at c043401a
 #4 [f06a9e6c] __do_page_fault at c0434493
 #5 [f06a9eec] do_page_fault at c083eb45
 #6 [f06a9f04] error_code (via page_fault) at c083c5d5
    EAX: 01fb470c EBX: fff35000 ECX: 00000003 EDX: 00000100 EBP:
    00000000
    DS:  007b     ESI: 9e201000 ES:  007b     EDI: 01fb4700 GS:  00e0
    CS:  0060     EIP: c083bc14 ERR: ffffffff EFLAGS: 00010246
 #7 [f06a9f38] _spin_lock at c083bc14
 #8 [f06a9f44] sys_mincore at c0507b7d
 #9 [f06a9fb0] system_call at c083becd
                         start           len
    EAX: ffffffda  EBX: 9e200000  ECX: 00001000  EDX: 6228537f
    DS:  007b      ESI: 00000000  ES:  007b      EDI: 003d0f00
    SS:  007b      ESP: 62285354  EBP: 62285388  GS:  0033
    CS:  0073      EIP: 00291416  ERR: 000000da  EFLAGS: 00000286

This should be a longstanding bug affecting x86 32bit PAE without THP.
Only archs with 64bit large pmd_t and 32bit unsigned long should be
affected.

With THP enabled the barrier() in pmd_none_or_trans_huge_or_clear_bad()
would partly hide the bug when the pmd transition from none to stable,
by forcing a re-read of the *pmd in pmd_offset_map_lock, but when THP is
enabled a new set of problem arises by the fact could then transition
freely in any of the none, pmd_trans_huge or pmd_trans_stable states.
So making the barrier in pmd_none_or_trans_huge_or_clear_bad()
unconditional isn't good idea and it would be a flakey solution.

This should be fully fixed by introducing a pmd_read_atomic that reads
the pmd in order with THP disabled, or by reading the pmd atomically
with cmpxchg8b with THP enabled.

Luckily this new race condition only triggers in the places that must
already be covered by pmd_none_or_trans_huge_or_clear_bad() so the fix
is localized there but this bug is not related to THP.

NOTE: this can trigger on x86 32bit systems with PAE enabled with more
than 4G of ram, otherwise the high part of the pmd will never risk to be
truncated because it would be zero at all times, in turn so hiding the
SMP race.

This bug was discovered and fully debugged by Ulrich, quote:

----
[..]
pmd_none_or_trans_huge_or_clear_bad() loads the content of edx and
eax.

    496 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t
    *pmd)
    497 {
    498         /* depend on compiler for an atomic pmd read */
    499         pmd_t pmdval = *pmd;

                                // edi = pmd pointer
0xc0507a74 <sys_mincore+548>:   mov    0x8(%esp),%edi
...
                                // edx = PTE page table high address
0xc0507a84 <sys_mincore+564>:   mov    0x4(%edi),%edx
...
                                // eax = PTE page table low address
0xc0507a8e <sys_mincore+574>:   mov    (%edi),%eax

[..]

Please note that the PMD is not read atomically. These are two "mov"
instructions where the high order bits of the PMD entry are fetched
first. Hence, the above machine code is prone to the following race.

-  The PMD entry {high|low} is 0x0000000000000000.
   The "mov" at 0xc0507a84 loads 0x00000000 into edx.

-  A page fault (on another CPU) sneaks in between the two "mov"
   instructions and instantiates the PMD.

-  The PMD entry {high|low} is now 0x00000003fda38067.
   The "mov" at 0xc0507a8e loads 0xfda38067 into eax.
----

Reported-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
David Rientjes
a7f638f999 mm, oom: normalize oom scores to oom_score_adj scale only for userspace
The oom_score_adj scale ranges from -1000 to 1000 and represents the
proportion of memory available to the process at allocation time.  This
means an oom_score_adj value of 300, for example, will bias a process as
though it was using an extra 30.0% of available memory and a value of
-350 will discount 35.0% of available memory from its usage.

The oom killer badness heuristic also uses this scale to report the oom
score for each eligible process in determining the "best" process to
kill.  Thus, it can only differentiate each process's memory usage by
0.1% of system RAM.

On large systems, this can end up being a large amount of memory: 256MB
on 256GB systems, for example.

This can be fixed by having the badness heuristic to use the actual
memory usage in scoring threads and then normalizing it to the
oom_score_adj scale for userspace.  This results in better comparison
between eligible threads for kill and no change from the userspace
perspective.

Suggested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
Satoru Moriya
fe35004fbf mm: avoid swapping out with swappiness==0
Sometimes we'd like to avoid swapping out anonymous memory.  In
particular, avoid swapping out pages of important process or process
groups while there is a reasonable amount of pagecache on RAM so that we
can satisfy our customers' requirements.

OTOH, we can control how aggressive the kernel will swap memory pages with
/proc/sys/vm/swappiness for global and
/sys/fs/cgroup/memory/memory.swappiness for each memcg.

But with current reclaim implementation, the kernel may swap out even if
we set swappiness=0 and there is pagecache in RAM.

This patch changes the behavior with swappiness==0.  If we set
swappiness==0, the kernel does not swap out completely (for global reclaim
until the amount of free pages and filebacked pages in a zone has been
reduced to something very very small (nr_free + nr_filebacked < high
watermark)).

Signed-off-by: Satoru Moriya <satoru.moriya@hds.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
Dave Hansen
c50ac05081 hugetlb: fix resv_map leak in error path
When called for anonymous (non-shared) mappings, hugetlb_reserve_pages()
does a resv_map_alloc().  It depends on code in hugetlbfs's
vm_ops->close() to release that allocation.

However, in the mmap() failure path, we do a plain unmap_region() without
the remove_vma() which actually calls vm_ops->close().

This is a decent fix.  This leak could get reintroduced if new code (say,
after hugetlb_reserve_pages() in hugetlbfs_file_mmap()) decides to return
an error.  But, I think it would have to unroll the reservation anyway.

Christoph's test case:

	http://marc.info/?l=linux-mm&m=133728900729735

This patch applies to 3.4 and later.  A version for earlier kernels is at
https://lkml.org/lkml/2012/5/22/418.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Christoph Lameter <cl@linux.com>
Tested-by: Christoph Lameter <cl@linux.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>	[2.6.32+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
Gavin Shan
5c2b8a162b mm/bootmem.c: cleanup on addition to bootmem data list
The objects of "struct bootmem_data_t" are linked together to form
double-linked list sequentially based on its minimal page frame number.

The current implementation implicitly supports the following cases,
which means the inserting point for current bootmem data depends on how
"list_for_each" works.  That makes the code a little hard to read.
Besides, "list_for_each" and "list_entry" can be replaced with
"list_for_each_entry".

        - The linked list is empty.
        - There has no entry in the linked list, whose minimal page
          frame number is bigger than current one.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:24 -07:00
Michal Hocko
e48982734e mm: consider all swapped back pages in used-once logic
Commit 6457474624 ("vmscan: detect mapped file pages used only once")
made mapped pages have another round in inactive list because they might
be just short lived and so we could consider them again next time.  This
heuristic helps to reduce pressure on the active list with a streaming
IO worklods.

This patch fixes a regression introduced by this commit for heavy shmem
based workloads because unlike Anon pages, which are excluded from this
heuristic because they are usually long lived, shmem pages are handled
as a regular page cache.

This doesn't work quite well, unfortunately, if the workload is mostly
backed by shmem (in memory database sitting on 80% of memory) with a
streaming IO in the background (backup - up to 20% of memory).  Anon
inactive list is full of (dirty) shmem pages when watermarks are hit.
Shmem pages are kept in the inactive list (they are referenced) in the
first round and it is hard to reclaim anything else so we reach lower
scanning priorities very quickly which leads to an excessive swap out.

Let's fix this by excluding all swap backed pages (they tend to be long
lived wrt.  the regular page cache anyway) from used-once heuristic and
rather activate them if they are referenced.

The customer's workload is shmem backed database (80% of RAM) and they
are measuring transactions/s with an IO in the background (20%).
Transactions touch more or less random rows in the table.  The
transaction rate fell by a factor of 3 (in the worst case) because of
commit 64574746.  This patch restores the previous numbers.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan@kernel.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: <stable@vger.kernel.org>	[2.6.34+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:23 -07:00
Mel Gorman
692569946f mm: document the meminfo and vmstat fields of relevance to transparent hugepages
Update Documentation/vm/transhuge.txt and
Documentation/filesystems/proc.txt with some information on monitoring
transparent huge page usage and the associated overhead.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:23 -07:00
Andrew Morton
51300cef41 mm/page_alloc.c: cleanups
- make pageflag_names[] const

- remove null termination of pageflag_names[]

Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:23 -07:00
Johannes Weiner
acc50c110c mm: page_alloc: catch out-of-date list of page flag names
String tables with names of enum items are always prone to go out of
sync with the enums themselves.  Ensure during compile time that the
name table of page flags has the same size as the page flags enum.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:23 -07:00
Gavin Shan
be9cd873e2 mm/buddy: dump PG_compound_lock page flag
The array pageflag_names[] does conversion from page flags into their
corresponding names so that a meaningful representation of the
corresponding page flag can be printed.  This mechanism is used while
dumping page frames.  However, the array missed PG_compound_lock.  So
the PG_compound_lock page flag would be printed as a digital number
instead of a meaningful string.

The patch fixes that and prints "compound_lock" for the PG_compound_lock
page flag.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:23 -07:00
Cong Wang
782182e53a mm: move readahead syscall to mm/readahead.c
It is better to define readahead(2) in mm/readahead.c than in
mm/filemap.c.

Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
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>
2012-05-29 16:22:23 -07:00