linux.git/mm/Makefile, branch v3.19

mm/page_owner: keep track of page owners

2014-12-13T20:42:48+00:00

This is the page owner tracking code which is introduced so far ago.  It
is resident on Andrew's tree, though, nobody tried to upstream so it
remain as is.  Our company uses this feature actively to debug memory leak
or to find a memory hogger so I decide to upstream this feature.

This functionality help us to know who allocates the page.  When
allocating a page, we store some information about allocation in extra
memory.  Later, if we need to know status of all pages, we can get and
analyze it from this stored information.

In previous version of this feature, extra memory is statically defined in
struct page, but, in this version, extra memory is allocated outside of
struct page.  It enables us to turn on/off this feature at boottime
without considerable memory waste.

Although we already have tracepoint for tracing page allocation/free,
using it to analyze page owner is rather complex.  We need to enlarge the
trace buffer for preventing overlapping until userspace program launched.
And, launched program continually dump out the trace buffer for later
analysis and it would change system behaviour with more possibility rather
than just keeping it in memory, so bad for debug.

Moreover, we can use page_owner feature further for various purposes.  For
example, we can use it for fragmentation statistics implemented in this
patch.  And, I also plan to implement some CMA failure debugging feature
using this interface.

I'd like to give the credit for all developers contributed this feature,
but, it's not easy because I don't know exact history.  Sorry about that.
Below is people who has "Signed-off-by" in the patches in Andrew's tree.

Contributor:
Alexander Nyberg 
Mel Gorman 
Dave Hansen 
Minchan Kim 
Michal Nazarewicz 
Andrew Morton 
Jungsoo Son 

Signed-off-by: Joonsoo Kim 
Cc: Mel Gorman 
Cc: Johannes Weiner 
Cc: Minchan Kim 
Cc: Dave Hansen 
Cc: Michal Nazarewicz 
Cc: Jungsoo Son 
Cc: Ingo Molnar 
Cc: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page_ext: resurrect struct page extending code for debugging

2014-12-13T20:42:48+00:00

When we debug something, we'd like to insert some information to every
page.  For this purpose, we sometimes modify struct page itself.  But,
this has drawbacks.  First, it requires re-compile.  This makes us
hesitate to use the powerful debug feature so development process is
slowed down.  And, second, sometimes it is impossible to rebuild the
kernel due to third party module dependency.  At third, system behaviour
would be largely different after re-compile, because it changes size of
struct page greatly and this structure is accessed by every part of
kernel.  Keeping this as it is would be better to reproduce errornous
situation.

This feature is intended to overcome above mentioned problems.  This
feature allocates memory for extended data per page in certain place
rather than the struct page itself.  This memory can be accessed by the
accessor functions provided by this code.  During the boot process, it
checks whether allocation of huge chunk of memory is needed or not.  If
not, it avoids allocating memory at all.  With this advantage, we can
include this feature into the kernel in default and can avoid rebuild and
solve related problems.

Until now, memcg uses this technique.  But, now, memcg decides to embed
their variable to struct page itself and it's code to extend struct page
has been removed.  I'd like to use this code to develop debug feature, so
this patch resurrect it.

To help these things to work well, this patch introduces two callbacks for
clients.  One is the need callback which is mandatory if user wants to
avoid useless memory allocation at boot-time.  The other is optional, init
callback, which is used to do proper initialization after memory is
allocated.  Detailed explanation about purpose of these functions is in
code comment.  Please refer it.

Others are completely same with previous extension code in memcg.

Signed-off-by: Joonsoo Kim 
Cc: Mel Gorman 
Cc: Johannes Weiner 
Cc: Minchan Kim 
Cc: Dave Hansen 
Cc: Michal Nazarewicz 
Cc: Jungsoo Son 
Cc: Ingo Molnar 
Cc: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: page_cgroup: rename file to mm/swap_cgroup.c

2014-12-11T01:41:09+00:00

Now that the external page_cgroup data structure and its lookup is gone,
the only code remaining in there is swap slot accounting.

Rename it and move the conditional compilation into mm/Makefile.

Signed-off-by: Johannes Weiner 
Acked-by: Michal Hocko 
Acked-by: Vladimir Davydov 
Acked-by: David S. Miller 
Acked-by: KAMEZAWA Hiroyuki 
Cc: "Kirill A. Shutemov" 
Cc: Tejun Heo 
Cc: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcontrol: lockless page counters

2014-12-11T01:41:04+00:00

Memory is internally accounted in bytes, using spinlock-protected 64-bit
counters, even though the smallest accounting delta is a page.  The
counter interface is also convoluted and does too many things.

Introduce a new lockless word-sized page counter API, then change all
memory accounting over to it.  The translation from and to bytes then only
happens when interfacing with userspace.

The removed locking overhead is noticable when scaling beyond the per-cpu
charge caches - on a 4-socket machine with 144-threads, the following test
shows the performance differences of 288 memcgs concurrently running a
page fault benchmark:

vanilla:

   18631648.500498      task-clock (msec)         #  140.643 CPUs utilized            ( +-  0.33% )
         1,380,638      context-switches          #    0.074 K/sec                    ( +-  0.75% )
            24,390      cpu-migrations            #    0.001 K/sec                    ( +-  8.44% )
     1,843,305,768      page-faults               #    0.099 M/sec                    ( +-  0.00% )
50,134,994,088,218      cycles                    #    2.691 GHz                      ( +-  0.33% )
         stalled-cycles-frontend
         stalled-cycles-backend
 8,049,712,224,651      instructions              #    0.16  insns per cycle          ( +-  0.04% )
 1,586,970,584,979      branches                  #   85.176 M/sec                    ( +-  0.05% )
     1,724,989,949      branch-misses             #    0.11% of all branches          ( +-  0.48% )

     132.474343877 seconds time elapsed                                          ( +-  0.21% )

lockless:

   12195979.037525      task-clock (msec)         #  133.480 CPUs utilized            ( +-  0.18% )
           832,850      context-switches          #    0.068 K/sec                    ( +-  0.54% )
            15,624      cpu-migrations            #    0.001 K/sec                    ( +- 10.17% )
     1,843,304,774      page-faults               #    0.151 M/sec                    ( +-  0.00% )
32,811,216,801,141      cycles                    #    2.690 GHz                      ( +-  0.18% )
         stalled-cycles-frontend
         stalled-cycles-backend
 9,999,265,091,727      instructions              #    0.30  insns per cycle          ( +-  0.10% )
 2,076,759,325,203      branches                  #  170.282 M/sec                    ( +-  0.12% )
     1,656,917,214      branch-misses             #    0.08% of all branches          ( +-  0.55% )

      91.369330729 seconds time elapsed                                          ( +-  0.45% )

On top of improved scalability, this also gets rid of the icky long long
types in the very heart of memcg, which is great for 32 bit and also makes
the code a lot more readable.

Notable differences between the old and new API:

- res_counter_charge() and res_counter_charge_nofail() become
  page_counter_try_charge() and page_counter_charge() resp. to match
  the more common kernel naming scheme of try_do()/do()

- res_counter_uncharge_until() is only ever used to cancel a local
  counter and never to uncharge bigger segments of a hierarchy, so
  it's replaced by the simpler page_counter_cancel()

- res_counter_set_limit() is replaced by page_counter_limit(), which
  expects its callers to serialize against themselves

- res_counter_memparse_write_strategy() is replaced by
  page_counter_limit(), which rounds down to the nearest page size -
  rather than up.  This is more reasonable for explicitely requested
  hard upper limits.

- to keep charging light-weight, page_counter_try_charge() charges
  speculatively, only to roll back if the result exceeds the limit.
  Because of this, a failing bigger charge can temporarily lock out
  smaller charges that would otherwise succeed.  The error is bounded
  to the difference between the smallest and the biggest possible
  charge size, so for memcg, this means that a failing THP charge can
  send base page charges into reclaim upto 2MB (4MB) before the limit
  would have been reached.  This should be acceptable.

[akpm@linux-foundation.org: add includes for WARN_ON_ONCE and memparse]
[akpm@linux-foundation.org: add includes for WARN_ON_ONCE, memparse, strncmp, and PAGE_SIZE]
Signed-off-by: Johannes Weiner 
Acked-by: Michal Hocko 
Acked-by: Vladimir Davydov 
Cc: Tejun Heo 
Cc: David Rientjes 
Cc: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'tiny/no-advice-fixup-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux

2014-10-12T13:21:57+00:00

Pull tinification fix from Josh "Paper Bag" Triplett:
 "Fixup to use PATCHv2 of 'mm: Support compiling out madvise and
  fadvise'"

* tag 'tiny/no-advice-fixup-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/josh/linux:
  mm: Support fadvise without CONFIG_MMU

mm: Support fadvise without CONFIG_MMU

2014-10-10T20:12:28+00:00

Commit d3ac21cacc24790eb45d735769f35753f5b56ceb ("mm: Support compiling
out madvise and fadvise") incorrectly made fadvise conditional on
CONFIG_MMU.  (The merged branch unintentionally incorporated v1 of the
patch rather than the fixed v2.)  Apply the delta from v1 to v2, to
allow fadvise without CONFIG_MMU.

Reported-by: Johannes Weiner 
Signed-off-by: Josh Triplett

mm/balloon_compaction: add vmstat counters and kpageflags bit

2014-10-10T02:26:01+00:00

Always mark pages with PageBalloon even if balloon compaction is disabled
and expose this mark in /proc/kpageflags as KPF_BALLOON.

Also this patch adds three counters into /proc/vmstat: "balloon_inflate",
"balloon_deflate" and "balloon_migrate".  They accumulate balloon
activity.  Current size of balloon is (balloon_inflate - balloon_deflate)
pages.

All generic balloon code now gathered under option CONFIG_MEMORY_BALLOON.
It should be selected by ballooning driver which wants use this feature.
Currently virtio-balloon is the only user.

Signed-off-by: Konstantin Khlebnikov 
Cc: Rafael Aquini 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: move debug code out of page_alloc.c

2014-10-10T02:25:58+00:00

dump_page() and dump_vma() are not specific to page_alloc.c, move them out
so page_alloc.c won't turn into the unofficial debug repository.

Signed-off-by: Sasha Levin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: Support compiling out madvise and fadvise

2014-08-18T00:44:24+00:00

Many embedded systems will not need these syscalls, and omitting them
saves space.  Add a new EXPERT config option CONFIG_ADVISE_SYSCALLS
(default y) to support compiling them out.

bloat-o-meter:
add/remove: 0/3 grow/shrink: 0/0 up/down: 0/-2250 (-2250)
function                                     old     new   delta
sys_fadvise64                                 57       -     -57
sys_fadvise64_64                             691       -    -691
sys_madvise                                 1502       -   -1502

Signed-off-by: Josh Triplett

mm/zpool: implement common zpool api to zbud/zsmalloc

2014-08-07T01:01:23+00:00

Add zpool api.

zpool provides an interface for memory storage, typically of compressed
memory.  Users can select what backend to use; currently the only
implementations are zbud, a low density implementation with up to two
compressed pages per storage page, and zsmalloc, a higher density
implementation with multiple compressed pages per storage page.

Signed-off-by: Dan Streetman 
Tested-by: Seth Jennings 
Cc: Minchan Kim 
Cc: Nitin Gupta 
Cc: Weijie Yang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds