<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/trace, branch v3.14.79</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v3.14.79</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v3.14.79'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2015-03-18T12:31:23Z</updated>
<entry>
<title>mm: when stealing freepages, also take pages created by splitting buddy page</title>
<updated>2015-03-18T12:31:23Z</updated>
<author>
<name>Vlastimil Babka</name>
<email>vbabka@suse.cz</email>
</author>
<published>2015-02-11T23:28:15Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=a4f3f96f850db69890f47984c60606a2362bee89'/>
<id>urn:sha1:a4f3f96f850db69890f47984c60606a2362bee89</id>
<content type='text'>
commit 99592d598eca62bdbbf62b59941c189176dfc614 upstream.

When studying page stealing, I noticed some weird looking decisions in
try_to_steal_freepages().  The first I assume is a bug (Patch 1), the
following two patches were driven by evaluation.

Testing was done with stress-highalloc of mmtests, using the
mm_page_alloc_extfrag tracepoint and postprocessing to get counts of how
often page stealing occurs for individual migratetypes, and what
migratetypes are used for fallbacks.  Arguably, the worst case of page
stealing is when UNMOVABLE allocation steals from MOVABLE pageblock.
RECLAIMABLE allocation stealing from MOVABLE allocation is also not ideal,
so the goal is to minimize these two cases.

The evaluation of v2 wasn't always clear win and Joonsoo questioned the
results.  Here I used different baseline which includes RFC compaction
improvements from [1].  I found that the compaction improvements reduce
variability of stress-highalloc, so there's less noise in the data.

First, let's look at stress-highalloc configured to do sync compaction,
and how these patches reduce page stealing events during the test.  First
column is after fresh reboot, other two are reiterations of test without
reboot.  That was all accumulater over 5 re-iterations (so the benchmark
was run 5x3 times with 5 fresh restarts).

Baseline:

                                                   3.19-rc4        3.19-rc4        3.19-rc4
                                                  5-nothp-1       5-nothp-2       5-nothp-3
Page alloc extfrag event                               10264225     8702233    10244125
Extfrag fragmenting                                    10263271     8701552    10243473
Extfrag fragmenting for unmovable                         13595       17616       15960
Extfrag fragmenting unmovable placed with movable          7989       12193        8447
Extfrag fragmenting for reclaimable                         658        1840        1817
Extfrag fragmenting reclaimable placed with movable         558        1677        1679
Extfrag fragmenting for movable                        10249018     8682096    10225696

With Patch 1:
                                                   3.19-rc4        3.19-rc4        3.19-rc4
                                                  6-nothp-1       6-nothp-2       6-nothp-3
Page alloc extfrag event                               11834954     9877523     9774860
Extfrag fragmenting                                    11833993     9876880     9774245
Extfrag fragmenting for unmovable                          7342       16129       11712
Extfrag fragmenting unmovable placed with movable          4191       10547        6270
Extfrag fragmenting for reclaimable                         373        1130         923
Extfrag fragmenting reclaimable placed with movable         302         906         738
Extfrag fragmenting for movable                        11826278     9859621     9761610

With Patch 2:
                                                   3.19-rc4        3.19-rc4        3.19-rc4
                                                  7-nothp-1       7-nothp-2       7-nothp-3
Page alloc extfrag event                                4725990     3668793     3807436
Extfrag fragmenting                                     4725104     3668252     3806898
Extfrag fragmenting for unmovable                          6678        7974        7281
Extfrag fragmenting unmovable placed with movable          2051        3829        4017
Extfrag fragmenting for reclaimable                         429        1208        1278
Extfrag fragmenting reclaimable placed with movable         369         976        1034
Extfrag fragmenting for movable                         4717997     3659070     3798339

With Patch 3:
                                                   3.19-rc4        3.19-rc4        3.19-rc4
                                                  8-nothp-1       8-nothp-2       8-nothp-3
Page alloc extfrag event                                5016183     4700142     3850633
Extfrag fragmenting                                     5015325     4699613     3850072
Extfrag fragmenting for unmovable                          1312        3154        3088
Extfrag fragmenting unmovable placed with movable          1115        2777        2714
Extfrag fragmenting for reclaimable                         437        1193        1097
Extfrag fragmenting reclaimable placed with movable         330         969         879
Extfrag fragmenting for movable                         5013576     4695266     3845887

In v2 we've seen apparent regression with Patch 1 for unmovable events,
this is now gone, suggesting it was indeed noise.  Here, each patch
improves the situation for unmovable events.  Reclaimable is improved by
patch 1 and then either the same modulo noise, or perhaps sligtly worse -
a small price for unmovable improvements, IMHO.  The number of movable
allocations falling back to other migratetypes is most noisy, but it's
reduced to half at Patch 2 nevertheless.  These are least critical as
compaction can move them around.

If we look at success rates, the patches don't affect them, that didn't change.

Baseline:
                             3.19-rc4              3.19-rc4              3.19-rc4
                            5-nothp-1             5-nothp-2             5-nothp-3
Success 1 Min         49.00 (  0.00%)       42.00 ( 14.29%)       41.00 ( 16.33%)
Success 1 Mean        51.00 (  0.00%)       45.00 ( 11.76%)       42.60 ( 16.47%)
Success 1 Max         55.00 (  0.00%)       51.00 (  7.27%)       46.00 ( 16.36%)
Success 2 Min         53.00 (  0.00%)       47.00 ( 11.32%)       44.00 ( 16.98%)
Success 2 Mean        59.60 (  0.00%)       50.80 ( 14.77%)       48.20 ( 19.13%)
Success 2 Max         64.00 (  0.00%)       56.00 ( 12.50%)       52.00 ( 18.75%)
Success 3 Min         84.00 (  0.00%)       82.00 (  2.38%)       78.00 (  7.14%)
Success 3 Mean        85.60 (  0.00%)       82.80 (  3.27%)       79.40 (  7.24%)
Success 3 Max         86.00 (  0.00%)       83.00 (  3.49%)       80.00 (  6.98%)

Patch 1:
                             3.19-rc4              3.19-rc4              3.19-rc4
                            6-nothp-1             6-nothp-2             6-nothp-3
Success 1 Min         49.00 (  0.00%)       44.00 ( 10.20%)       44.00 ( 10.20%)
Success 1 Mean        51.80 (  0.00%)       46.00 ( 11.20%)       45.80 ( 11.58%)
Success 1 Max         54.00 (  0.00%)       49.00 (  9.26%)       49.00 (  9.26%)
Success 2 Min         58.00 (  0.00%)       49.00 ( 15.52%)       48.00 ( 17.24%)
Success 2 Mean        60.40 (  0.00%)       51.80 ( 14.24%)       50.80 ( 15.89%)
Success 2 Max         63.00 (  0.00%)       54.00 ( 14.29%)       55.00 ( 12.70%)
Success 3 Min         84.00 (  0.00%)       81.00 (  3.57%)       79.00 (  5.95%)
Success 3 Mean        85.00 (  0.00%)       81.60 (  4.00%)       79.80 (  6.12%)
Success 3 Max         86.00 (  0.00%)       82.00 (  4.65%)       82.00 (  4.65%)

Patch 2:

                             3.19-rc4              3.19-rc4              3.19-rc4
                            7-nothp-1             7-nothp-2             7-nothp-3
Success 1 Min         50.00 (  0.00%)       44.00 ( 12.00%)       39.00 ( 22.00%)
Success 1 Mean        52.80 (  0.00%)       45.60 ( 13.64%)       42.40 ( 19.70%)
Success 1 Max         55.00 (  0.00%)       46.00 ( 16.36%)       47.00 ( 14.55%)
Success 2 Min         52.00 (  0.00%)       48.00 (  7.69%)       45.00 ( 13.46%)
Success 2 Mean        53.40 (  0.00%)       49.80 (  6.74%)       48.80 (  8.61%)
Success 2 Max         57.00 (  0.00%)       52.00 (  8.77%)       52.00 (  8.77%)
Success 3 Min         84.00 (  0.00%)       81.00 (  3.57%)       79.00 (  5.95%)
Success 3 Mean        85.00 (  0.00%)       82.40 (  3.06%)       79.60 (  6.35%)
Success 3 Max         86.00 (  0.00%)       83.00 (  3.49%)       80.00 (  6.98%)

Patch 3:
                             3.19-rc4              3.19-rc4              3.19-rc4
                            8-nothp-1             8-nothp-2             8-nothp-3
Success 1 Min         46.00 (  0.00%)       44.00 (  4.35%)       42.00 (  8.70%)
Success 1 Mean        50.20 (  0.00%)       45.60 (  9.16%)       44.00 ( 12.35%)
Success 1 Max         52.00 (  0.00%)       47.00 (  9.62%)       47.00 (  9.62%)
Success 2 Min         53.00 (  0.00%)       49.00 (  7.55%)       48.00 (  9.43%)
Success 2 Mean        55.80 (  0.00%)       50.60 (  9.32%)       49.00 ( 12.19%)
Success 2 Max         59.00 (  0.00%)       52.00 ( 11.86%)       51.00 ( 13.56%)
Success 3 Min         84.00 (  0.00%)       80.00 (  4.76%)       79.00 (  5.95%)
Success 3 Mean        85.40 (  0.00%)       81.60 (  4.45%)       80.40 (  5.85%)
Success 3 Max         87.00 (  0.00%)       83.00 (  4.60%)       82.00 (  5.75%)

While there's no improvement here, I consider reduced fragmentation events
to be worth on its own.  Patch 2 also seems to reduce scanning for free
pages, and migrations in compaction, suggesting it has somewhat less work
to do:

Patch 1:

Compaction stalls                 4153        3959        3978
Compaction success                1523        1441        1446
Compaction failures               2630        2517        2531
Page migrate success           4600827     4943120     5104348
Page migrate failure             19763       16656       17806
Compaction pages isolated      9597640    10305617    10653541
Compaction migrate scanned    77828948    86533283    87137064
Compaction free scanned      517758295   521312840   521462251
Compaction cost                   5503        5932        6110

Patch 2:

Compaction stalls                 3800        3450        3518
Compaction success                1421        1316        1317
Compaction failures               2379        2134        2201
Page migrate success           4160421     4502708     4752148
Page migrate failure             19705       14340       14911
Compaction pages isolated      8731983     9382374     9910043
Compaction migrate scanned    98362797    96349194    98609686
Compaction free scanned      496512560   469502017   480442545
Compaction cost                   5173        5526        5811

As with v2, /proc/pagetypeinfo appears unaffected with respect to numbers
of unmovable and reclaimable pageblocks.

Configuring the benchmark to allocate like THP page fault (i.e.  no sync
compaction) gives much noisier results for iterations 2 and 3 after
reboot.  This is not so surprising given how [1] offers lower improvements
in this scenario due to less restarts after deferred compaction which
would change compaction pivot.

Baseline:
                                                   3.19-rc4        3.19-rc4        3.19-rc4
                                                    5-thp-1         5-thp-2         5-thp-3
Page alloc extfrag event                                8148965     6227815     6646741
Extfrag fragmenting                                     8147872     6227130     6646117
Extfrag fragmenting for unmovable                         10324       12942       15975
Extfrag fragmenting unmovable placed with movable          5972        8495       10907
Extfrag fragmenting for reclaimable                         601        1707        2210
Extfrag fragmenting reclaimable placed with movable         520        1570        2000
Extfrag fragmenting for movable                         8136947     6212481     6627932

Patch 1:
                                                   3.19-rc4        3.19-rc4        3.19-rc4
                                                    6-thp-1         6-thp-2         6-thp-3
Page alloc extfrag event                                8345457     7574471     7020419
Extfrag fragmenting                                     8343546     7573777     7019718
Extfrag fragmenting for unmovable                         10256       18535       30716
Extfrag fragmenting unmovable placed with movable          6893       11726       22181
Extfrag fragmenting for reclaimable                         465        1208        1023
Extfrag fragmenting reclaimable placed with movable         353         996         843
Extfrag fragmenting for movable                         8332825     7554034     6987979

Patch 2:
                                                   3.19-rc4        3.19-rc4        3.19-rc4
                                                    7-thp-1         7-thp-2         7-thp-3
Page alloc extfrag event                                3512847     3020756     2891625
Extfrag fragmenting                                     3511940     3020185     2891059
Extfrag fragmenting for unmovable                          9017        6892        6191
Extfrag fragmenting unmovable placed with movable          1524        3053        2435
Extfrag fragmenting for reclaimable                         445        1081        1160
Extfrag fragmenting reclaimable placed with movable         375         918         986
Extfrag fragmenting for movable                         3502478     3012212     2883708

Patch 3:
                                                   3.19-rc4        3.19-rc4        3.19-rc4
                                                    8-thp-1         8-thp-2         8-thp-3
Page alloc extfrag event                                3181699     3082881     2674164
Extfrag fragmenting                                     3180812     3082303     2673611
Extfrag fragmenting for unmovable                          1201        4031        4040
Extfrag fragmenting unmovable placed with movable           974        3611        3645
Extfrag fragmenting for reclaimable                         478        1165        1294
Extfrag fragmenting reclaimable placed with movable         387         985        1030
Extfrag fragmenting for movable                         3179133     3077107     2668277

The improvements for first iteration are clear, the rest is much noisier
and can appear like regression for Patch 1.  Anyway, patch 2 rectifies it.

Allocation success rates are again unaffected so there's no point in
making this e-mail any longer.

[1] http://marc.info/?l=linux-mm&amp;m=142166196321125&amp;w=2

This patch (of 3):

When __rmqueue_fallback() is called to allocate a page of order X, it will
find a page of order Y &gt;= X of a fallback migratetype, which is different
from the desired migratetype.  With the help of try_to_steal_freepages(),
it may change the migratetype (to the desired one) also of:

1) all currently free pages in the pageblock containing the fallback page
2) the fallback pageblock itself
3) buddy pages created by splitting the fallback page (when Y &gt; X)

These decisions take the order Y into account, as well as the desired
migratetype, with the goal of preventing multiple fallback allocations
that could e.g.  distribute UNMOVABLE allocations among multiple
pageblocks.

Originally, decision for 1) has implied the decision for 3).  Commit
47118af076f6 ("mm: mmzone: MIGRATE_CMA migration type added") changed that
(probably unintentionally) so that the buddy pages in case 3) are always
changed to the desired migratetype, except for CMA pageblocks.

Commit fef903efcf0c ("mm/page_allo.c: restructure free-page stealing code
and fix a bug") did some refactoring and added a comment that the case of
3) is intended.  Commit 0cbef29a7821 ("mm: __rmqueue_fallback() should
respect pageblock type") removed the comment and tried to restore the
original behavior where 1) implies 3), but due to the previous
refactoring, the result is instead that only 2) implies 3) - and the
conditions for 2) are less frequently met than conditions for 1).  This
may increase fragmentation in situations where the code decides to steal
all free pages from the pageblock (case 1)), but then gives back the buddy
pages produced by splitting.

This patch restores the original intended logic where 1) implies 3).
During testing with stress-highalloc from mmtests, this has shown to
decrease the number of events where UNMOVABLE and RECLAIMABLE allocations
steal from MOVABLE pageblocks, which can lead to permanent fragmentation.
In some cases it has increased the number of events when MOVABLE
allocations steal from UNMOVABLE or RECLAIMABLE pageblocks, but these are
fixable by sync compaction and thus less harmful.

Note that evaluation has shown that the behavior introduced by
47118af076f6 for buddy pages in case 3) is actually even better than the
original logic, so the following patch will introduce it properly once
again.  For stable backports of this patch it makes thus sense to only fix
versions containing 0cbef29a7821.

[iamjoonsoo.kim@lge.com: tracepoint fix]
Signed-off-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Acked-by: Mel Gorman &lt;mgorman@suse.de&gt;
Cc: Zhang Yanfei &lt;zhangyanfei@cn.fujitsu.com&gt;
Acked-by: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: David Rientjes &lt;rientjes@google.com&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: "Aneesh Kumar K.V" &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: "Kirill A. Shutemov" &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.cz&gt;
Cc: KOSAKI Motohiro &lt;kosaki.motohiro@jp.fujitsu.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>mm: pagemap: avoid unnecessary overhead when tracepoints are deactivated</title>
<updated>2015-01-30T01:40:52Z</updated>
<author>
<name>Mel Gorman</name>
<email>mgorman@suse.de</email>
</author>
<published>2014-08-06T23:07:11Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=84532d77391d45a2a204c039664fa6dbcc121a01'/>
<id>urn:sha1:84532d77391d45a2a204c039664fa6dbcc121a01</id>
<content type='text'>
commit 24b7e5819ad5cbef2b7c7376510862aa8319d240 upstream.

This was formerly the series "Improve sequential read throughput" which
noted some major differences in performance of tiobench since 3.0.
While there are a number of factors, two that dominated were the
introduction of the fair zone allocation policy and changes to CFQ.

The behaviour of fair zone allocation policy makes more sense than
tiobench as a benchmark and CFQ defaults were not changed due to
insufficient benchmarking.

This series is what's left.  It's one functional fix to the fair zone
allocation policy when used on NUMA machines and a reduction of overhead
in general.  tiobench was used for the comparison despite its flaws as
an IO benchmark as in this case we are primarily interested in the
overhead of page allocator and page reclaim activity.

On UMA, it makes little difference to overhead

          3.16.0-rc3   3.16.0-rc3
             vanilla lowercost-v5
User          383.61      386.77
System        403.83      401.74
Elapsed      5411.50     5413.11

On a 4-socket NUMA machine it's a bit more noticable

          3.16.0-rc3   3.16.0-rc3
             vanilla lowercost-v5
User          746.94      802.00
System      65336.22    40852.33
Elapsed     27553.52    27368.46

This patch (of 6):

The LRU insertion and activate tracepoints take PFN as a parameter
forcing the overhead to the caller.  Move the overhead to the tracepoint
fast-assign method to ensure the cost is only incurred when the
tracepoint is active.

Signed-off-by: Mel Gorman &lt;mgorman@suse.de&gt;
Acked-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Mel Gorman &lt;mgorman@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>tracing/sched: Check preempt_count() for current when reading task-&gt;state</title>
<updated>2015-01-16T14:59:32Z</updated>
<author>
<name>Steven Rostedt (Red Hat)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2014-12-10T22:31:07Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=37b2a5a7c849b7242322688ce380d0a1cc1b1d0f'/>
<id>urn:sha1:37b2a5a7c849b7242322688ce380d0a1cc1b1d0f</id>
<content type='text'>
commit aee4e5f3d3abb7a2239dd02f6d8fb173413fd02f upstream.

When recording the state of a task for the sched_switch tracepoint a check of
task_preempt_count() is performed to see if PREEMPT_ACTIVE is set. This is
because, technically, a task being preempted is really in the TASK_RUNNING
state, and that is what should be recorded when tracing a sched_switch,
even if the task put itself into another state (it hasn't scheduled out
in that state yet).

But with the change to use per_cpu preempt counts, the
task_thread_info(p)-&gt;preempt_count is no longer used, and instead
task_preempt_count(p) is used.

The problem is that this does not use the current preempt count but a stale
one from a previous sched_switch. The task_preempt_count(p) uses
saved_preempt_count and not preempt_count(). But for tracing sched_switch,
if p is current, we really want preempt_count().

I hit this bug when I was tracing sleep and the call from do_nanosleep()
scheduled out in the "RUNNING" state.

           sleep-4290  [000] 537272.259992: sched_switch:         sleep:4290 [120] R ==&gt; swapper/0:0 [120]
           sleep-4290  [000] 537272.260015: kernel_stack:         &lt;stack trace&gt;
=&gt; __schedule (ffffffff8150864a)
=&gt; schedule (ffffffff815089f8)
=&gt; do_nanosleep (ffffffff8150b76c)
=&gt; hrtimer_nanosleep (ffffffff8108d66b)
=&gt; SyS_nanosleep (ffffffff8108d750)
=&gt; return_to_handler (ffffffff8150e8e5)
=&gt; tracesys_phase2 (ffffffff8150c844)

After a bit of hair pulling, I found that the state was really
TASK_INTERRUPTIBLE, but the saved_preempt_count had an old PREEMPT_ACTIVE
set and caused the sched_switch tracepoint to show it as RUNNING.

Link: http://lkml.kernel.org/r/20141210174428.3cb7542a@gandalf.local.home

Acked-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Fixes: 01028747559a "sched: Create more preempt_count accessors"
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>mm/compaction: do not count migratepages when unnecessary</title>
<updated>2014-11-21T17:23:07Z</updated>
<author>
<name>Vlastimil Babka</name>
<email>vbabka@suse.cz</email>
</author>
<published>2014-06-04T23:08:32Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=41c9323cf11df2465a3064591b669d90111b6f9e'/>
<id>urn:sha1:41c9323cf11df2465a3064591b669d90111b6f9e</id>
<content type='text'>
commit f8c9301fa5a2a8b873c67f2a3d8230d5c13f61b7 upstream.

During compaction, update_nr_listpages() has been used to count remaining
non-migrated and free pages after a call to migrage_pages().  The
freepages counting has become unneccessary, and it turns out that
migratepages counting is also unnecessary in most cases.

The only situation when it's needed to count cc-&gt;migratepages is when
migrate_pages() returns with a negative error code.  Otherwise, the
non-negative return value is the number of pages that were not migrated,
which is exactly the count of remaining pages in the cc-&gt;migratepages
list.

Furthermore, any non-zero count is only interesting for the tracepoint of
mm_compaction_migratepages events, because after that all remaining
unmigrated pages are put back and their count is set to 0.

This patch therefore removes update_nr_listpages() completely, and changes
the tracepoint definition so that the manual counting is done only when
the tracepoint is enabled, and only when migrate_pages() returns a
negative error code.

Furthermore, migrate_pages() and the tracepoints won't be called when
there's nothing to migrate.  This potentially avoids some wasted cycles
and reduces the volume of uninteresting mm_compaction_migratepages events
where "nr_migrated=0 nr_failed=0".  In the stress-highalloc mmtest, this
was about 75% of the events.  The mm_compaction_isolate_migratepages event
is better for determining that nothing was isolated for migration, and
this one was just duplicating the info.

Signed-off-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Reviewed-by: Naoya Horiguchi &lt;n-horiguchi@ah.jp.nec.com&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Mel Gorman &lt;mgorman@suse.de&gt;
Cc: Joonsoo Kim &lt;iamjoonsoo.kim@lge.com&gt;
Cc: Bartlomiej Zolnierkiewicz &lt;b.zolnierkie@samsung.com&gt;
Acked-by: Michal Nazarewicz &lt;mina86@mina86.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Mel Gorman &lt;mgorman@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>tracing: Fix syscall_*regfunc() vs copy_process() race</title>
<updated>2014-07-07T01:57:29Z</updated>
<author>
<name>Oleg Nesterov</name>
<email>oleg@redhat.com</email>
</author>
<published>2014-04-13T18:58:54Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=6a2e92a4a660b38fcf15a134ffc98e6b8526e577'/>
<id>urn:sha1:6a2e92a4a660b38fcf15a134ffc98e6b8526e577</id>
<content type='text'>
commit 4af4206be2bd1933cae20c2b6fb2058dbc887f7c upstream.

syscall_regfunc() and syscall_unregfunc() should set/clear
TIF_SYSCALL_TRACEPOINT system-wide, but do_each_thread() can race
with copy_process() and miss the new child which was not added to
the process/thread lists yet.

Change copy_process() to update the child's TIF_SYSCALL_TRACEPOINT
under tasklist.

Link: http://lkml.kernel.org/p/20140413185854.GB20668@redhat.com

Fixes: a871bd33a6c0 "tracing: Add syscall tracepoints"
Acked-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Acked-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Signed-off-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>trace: module: Maintain a valid user count</title>
<updated>2014-06-07T17:28:20Z</updated>
<author>
<name>Romain Izard</name>
<email>romain.izard.pro@gmail.com</email>
</author>
<published>2014-03-04T09:09:39Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=df02df0a9269f9d27c0d3738e330b2c166445f76'/>
<id>urn:sha1:df02df0a9269f9d27c0d3738e330b2c166445f76</id>
<content type='text'>
commit 098507ae3ec2331476fb52e85d4040c1cc6d0ef4 upstream.

The replacement of the 'count' variable by two variables 'incs' and
'decs' to resolve some race conditions during module unloading was done
in parallel with some cleanup in the trace subsystem, and was integrated
as a merge.

Unfortunately, the formula for this replacement was wrong in the tracing
code, and the refcount in the traces was not usable as a result.

Use 'count = incs - decs' to compute the user count.

Link: http://lkml.kernel.org/p/1393924179-9147-1-git-send-email-romain.izard.pro@gmail.com

Acked-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Fixes: c1ab9cab7509 "merge conflict resolution"
Signed-off-by: Romain Izard &lt;romain.izard.pro@gmail.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>blktrace: fix accounting of partially completed requests</title>
<updated>2014-05-31T20:20:28Z</updated>
<author>
<name>Roman Pen</name>
<email>r.peniaev@gmail.com</email>
</author>
<published>2014-03-04T14:13:10Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=0a8eda9c00ef37e8b40de77f2b0714317191bcf2'/>
<id>urn:sha1:0a8eda9c00ef37e8b40de77f2b0714317191bcf2</id>
<content type='text'>
commit af5040da01ef980670b3741b3e10733ee3e33566 upstream.

trace_block_rq_complete does not take into account that request can
be partially completed, so we can get the following incorrect output
of blkparser:

  C   R 232 + 240 [0]
  C   R 240 + 232 [0]
  C   R 248 + 224 [0]
  C   R 256 + 216 [0]

but should be:

  C   R 232 + 8 [0]
  C   R 240 + 8 [0]
  C   R 248 + 8 [0]
  C   R 256 + 8 [0]

Also, the whole output summary statistics of completed requests and
final throughput will be incorrect.

This patch takes into account real completion size of the request and
fixes wrong completion accounting.

Signed-off-by: Roman Pen &lt;r.peniaev@gmail.com&gt;
CC: Steven Rostedt &lt;rostedt@goodmis.org&gt;
CC: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
CC: Ingo Molnar &lt;mingo@redhat.com&gt;
CC: linux-kernel@vger.kernel.org
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>tracing: Fix array size mismatch in format string</title>
<updated>2014-03-20T17:21:05Z</updated>
<author>
<name>Vaibhav Nagarnaik</name>
<email>vnagarnaik@google.com</email>
</author>
<published>2014-02-14T03:51:48Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=87291347c49dc40aa339f587b209618201c2e527'/>
<id>urn:sha1:87291347c49dc40aa339f587b209618201c2e527</id>
<content type='text'>
In event format strings, the array size is reported in two locations.
One in array subscript and then via the "size:" attribute. The values
reported there have a mismatch.

For e.g., in sched:sched_switch the prev_comm and next_comm character
arrays have subscript values as [32] where as the actual field size is
16.

name: sched_switch
ID: 301
format:
        field:unsigned short common_type;       offset:0;       size:2; signed:0;
        field:unsigned char common_flags;       offset:2;       size:1; signed:0;
        field:unsigned char common_preempt_count;       offset:3;       size:1;signed:0;
        field:int common_pid;   offset:4;       size:4; signed:1;

        field:char prev_comm[32];       offset:8;       size:16;        signed:1;
        field:pid_t prev_pid;   offset:24;      size:4; signed:1;
        field:int prev_prio;    offset:28;      size:4; signed:1;
        field:long prev_state;  offset:32;      size:8; signed:1;
        field:char next_comm[32];       offset:40;      size:16;        signed:1;
        field:pid_t next_pid;   offset:56;      size:4; signed:1;
        field:int next_prio;    offset:60;      size:4; signed:1;

After bisection, the following commit was blamed:
92edca0 tracing: Use direct field, type and system names

This commit removes the duplication of strings for field-&gt;name and
field-&gt;type assuming that all the strings passed in
__trace_define_field() are immutable. This is not true for arrays, where
the type string is created in event_storage variable and field-&gt;type for
all array fields points to event_storage.

Use __stringify() to create a string constant for the type string.

Also, get rid of event_storage and event_storage_mutex that are not
needed anymore.

also, an added benefit is that this reduces the overhead of events a bit more:

   text    data     bss     dec     hex filename
8424787 2036472 1302528 11763787         b3804b vmlinux
8420814 2036408 1302528 11759750         b37086 vmlinux.patched

Link: http://lkml.kernel.org/r/1392349908-29685-1-git-send-email-vnagarnaik@google.com

Cc: Laurent Chavey &lt;chavey@google.com&gt;
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Vaibhav Nagarnaik &lt;vnagarnaik@google.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'nfs-for-3.14-5' of git://git.linux-nfs.org/projects/trondmy/linux-nfs</title>
<updated>2014-03-10T02:17:39Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-03-10T02:17:39Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=fe9ea91cde29125a3417890678f4d886cec4a71e'/>
<id>urn:sha1:fe9ea91cde29125a3417890678f4d886cec4a71e</id>
<content type='text'>
Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

   - Fix another nfs4_sequence corruptor in RELEASE_LOCKOWNER
   - Fix an Oopsable delegation callback race
   - Fix another bad stateid infinite loop
   - Fail the data server I/O is the stateid represents a lost lock
   - Fix an Oopsable sunrpc trace event"

* tag 'nfs-for-3.14-5' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: Fix oops when trace sunrpc_task events in nfs client
  NFSv4: Fail the truncate() if the lock/open stateid is invalid
  NFSv4.1 Fail data server I/O if stateid represents a lost lock
  NFSv4: Fix the return value of nfs4_select_rw_stateid
  NFSv4: nfs4_stateid_is_current should return 'true' for an invalid stateid
  NFS: Fix a delegation callback race
  NFSv4: Fix another nfs4_sequence corruptor
</content>
</entry>
<entry>
<title>SUNRPC: Fix oops when trace sunrpc_task events in nfs client</title>
<updated>2014-03-08T00:10:08Z</updated>
<author>
<name>Ditang Chen</name>
<email>chendt.fnst@cn.fujitsu.com</email>
</author>
<published>2014-03-07T05:27:57Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=2ca310fc4160ed0420da65534a21ae77b24326a8'/>
<id>urn:sha1:2ca310fc4160ed0420da65534a21ae77b24326a8</id>
<content type='text'>
When tracking sunrpc_task events in nfs client, the clnt pointer may be NULL.

[  139.269266] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
[  139.269915] IP: [&lt;ffffffffa026f216&gt;] ftrace_raw_event_rpc_task_running+0x86/0xf0 [sunrpc]
[  139.269915] PGD 1d293067 PUD 1d294067 PMD 0
[  139.269915] Oops: 0000 [#1] SMP
[  139.269915] Modules linked in: nfsv4 dns_resolver nfs lockd sunrpc fscache sg ppdev e1000
serio_raw pcspkr parport_pc parport i2c_piix4 i2c_core microcode xfs libcrc32c sd_mod sr_mod
cdrom ata_generic crc_t10dif crct10dif_common pata_acpi ahci libahci ata_piix libata dm_mirror
dm_region_hash dm_log dm_mod
[  139.269915] CPU: 0 PID: 59 Comm: kworker/0:2 Not tainted 3.10.0-84.el7.x86_64 #1
[  139.269915] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  139.269915] Workqueue: rpciod rpc_async_schedule [sunrpc]
[  139.269915] task: ffff88001b598000 ti: ffff88001b632000 task.ti: ffff88001b632000
[  139.269915] RIP: 0010:[&lt;ffffffffa026f216&gt;]  [&lt;ffffffffa026f216&gt;] ftrace_raw_event_rpc_task_running+0x86/0xf0 [sunrpc]
[  139.269915] RSP: 0018:ffff88001b633d70  EFLAGS: 00010206
[  139.269915] RAX: ffff88001dfc5338 RBX: ffff88001cc37a00 RCX: ffff88001dfc5334
[  139.269915] RDX: ffff88001dfc5338 RSI: 0000000000000000 RDI: ffff88001dfc533c
[  139.269915] RBP: ffff88001b633db0 R08: 000000000000002c R09: 000000000000000a
[  139.269915] R10: 0000000000062180 R11: 00000020759fb9dc R12: ffffffffa0292c20
[  139.269915] R13: ffff88001dfc5334 R14: 0000000000000000 R15: 0000000000000000
[  139.269915] FS:  0000000000000000(0000) GS:ffff88001fc00000(0000) knlGS:0000000000000000
[  139.269915] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  139.269915] CR2: 0000000000000004 CR3: 000000001d290000 CR4: 00000000000006f0
[  139.269915] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  139.269915] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  139.269915] Stack:
[  139.269915]  000000001b633d98 0000000000000246 ffff88001df1dc00 ffff88001cc37a00
[  139.269915]  ffff88001bc35e60 0000000000000000 ffff88001ffa0a48 ffff88001bc35ee0
[  139.269915]  ffff88001b633e08 ffffffffa02704b5 0000000000010000 ffff88001cc37a70
[  139.269915] Call Trace:
[  139.269915]  [&lt;ffffffffa02704b5&gt;] __rpc_execute+0x1d5/0x400 [sunrpc]
[  139.269915]  [&lt;ffffffffa0270706&gt;] rpc_async_schedule+0x26/0x30 [sunrpc]
[  139.269915]  [&lt;ffffffff8107867b&gt;] process_one_work+0x17b/0x460
[  139.269915]  [&lt;ffffffff8107942b&gt;] worker_thread+0x11b/0x400
[  139.269915]  [&lt;ffffffff81079310&gt;] ? rescuer_thread+0x3e0/0x3e0
[  139.269915]  [&lt;ffffffff8107fc80&gt;] kthread+0xc0/0xd0
[  139.269915]  [&lt;ffffffff8107fbc0&gt;] ? kthread_create_on_node+0x110/0x110
[  139.269915]  [&lt;ffffffff815d122c&gt;] ret_from_fork+0x7c/0xb0
[  139.269915]  [&lt;ffffffff8107fbc0&gt;] ? kthread_create_on_node+0x110/0x110
[  139.269915] Code: 4c 8b 45 c8 48 8d 7d d0 89 4d c4 41 89 c9 b9 28 00 00 00 e8 9d b4 e9
e0 48 85 c0 49 89 c5 74 a2 48 89 c7 e8 9d 3f e9 e0 48 89 c2 &lt;41&gt; 8b 46 04 48 8b 7d d0 4c
89 e9 4c 89 e6 89 42 0c 0f b7 83 d4
[  139.269915] RIP  [&lt;ffffffffa026f216&gt;] ftrace_raw_event_rpc_task_running+0x86/0xf0 [sunrpc]
[  139.269915]  RSP &lt;ffff88001b633d70&gt;
[  139.269915] CR2: 0000000000000004
[  140.946406] ---[ end trace ba486328b98d7622 ]---

Signed-off-by: Ditang Chen &lt;chendt.fnst@cn.fujitsu.com&gt;
Signed-off-by: Trond Myklebust &lt;trond.myklebust@primarydata.com&gt;
</content>
</entry>
</feed>
