Commit Graph

590 Commits

Author SHA1 Message Date
Paul E. McKenney fd4b352687 rcu: Update RCU_FAST_NO_HZ tracing for lazy callbacks
In the current code, a short dyntick-idle interval (where there is
at least one non-lazy callback on the CPU) and a long dyntick-idle
interval (where there are only lazy callbacks on the CPU) are traced
identically, which can be less than helpful.  This commit therefore
emits different event traces in these two cases.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
2012-06-06 20:43:27 -07:00
Mel Gorman 23b9da55c5 mm: vmscan: remove reclaim_mode_t
There is little motiviation for reclaim_mode_t once RECLAIM_MODE_[A]SYNC
and lumpy reclaim have been removed.  This patch gets rid of
reclaim_mode_t as well and improves the documentation about what
reclaim/compaction is and when it is triggered.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ying Han <yinghan@google.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:19 -07:00
Mel Gorman 41ac1999c3 mm: vmscan: do not stall on writeback during memory compaction
This patch stops reclaim/compaction entering sync reclaim as this was
only intended for lumpy reclaim and an oversight.  Page migration has
its own logic for stalling on writeback pages if necessary and memory
compaction is already using it.

Waiting on page writeback is bad for a number of reasons but the primary
one is that waiting on writeback to a slow device like USB can take a
considerable length of time.  Page reclaim instead uses
wait_iff_congested() to throttle if too many dirty pages are being
scanned.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ying Han <yinghan@google.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:19 -07:00
Mel Gorman c53919adc0 mm: vmscan: remove lumpy reclaim
This series removes lumpy reclaim and some stalling logic that was
unintentionally being used by memory compaction.  The end result is that
stalling on dirty pages during page reclaim now depends on
wait_iff_congested().

Four kernels were compared

  3.3.0     vanilla
  3.4.0-rc2 vanilla
  3.4.0-rc2 lumpyremove-v2 is patch one from this series
  3.4.0-rc2 nosync-v2r3 is the full series

Removing lumpy reclaim saves almost 900 bytes of text whereas the full
series removes 1200 bytes.

     text     data      bss       dec     hex  filename
  6740375  1927944  2260992  10929311  a6c49f  vmlinux-3.4.0-rc2-vanilla
  6739479  1927944  2260992  10928415  a6c11f  vmlinux-3.4.0-rc2-lumpyremove-v2
  6739159  1927944  2260992  10928095  a6bfdf  vmlinux-3.4.0-rc2-nosync-v2

There are behaviour changes in the series and so tests were run with
monitoring of ftrace events.  This disrupts results so the performance
results are distorted but the new behaviour should be clearer.

fs-mark running in a threaded configuration showed little of interest as
it did not push reclaim aggressively

  FS-Mark Multi Threaded
                          3.3.0-vanilla       rc2-vanilla       lumpyremove-v2r3       nosync-v2r3
  Files/s  min           3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)
  Files/s  mean          3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)
  Files/s  stddev        0.00 ( 0.00%)        0.00 ( 0.00%)        0.00 ( 0.00%)        0.00 ( 0.00%)
  Files/s  max           3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)
  Overhead min      508667.00 ( 0.00%)   521350.00 (-2.49%)   544292.00 (-7.00%)   547168.00 (-7.57%)
  Overhead mean     551185.00 ( 0.00%)   652690.73 (-18.42%)   991208.40 (-79.83%)   570130.53 (-3.44%)
  Overhead stddev    18200.69 ( 0.00%)   331958.29 (-1723.88%)  1579579.43 (-8578.68%)     9576.81 (47.38%)
  Overhead max      576775.00 ( 0.00%)  1846634.00 (-220.17%)  6901055.00 (-1096.49%)   585675.00 (-1.54%)
  MMTests Statistics: duration
  Sys Time Running Test (seconds)             309.90    300.95    307.33    298.95
  User+Sys Time Running Test (seconds)        319.32    309.67    315.69    307.51
  Total Elapsed Time (seconds)               1187.85   1193.09   1191.98   1193.73

  MMTests Statistics: vmstat
  Page Ins                                       80532       82212       81420       79480
  Page Outs                                  111434984   111456240   111437376   111582628
  Swap Ins                                           0           0           0           0
  Swap Outs                                          0           0           0           0
  Direct pages scanned                           44881       27889       27453       34843
  Kswapd pages scanned                        25841428    25860774    25861233    25843212
  Kswapd pages reclaimed                      25841393    25860741    25861199    25843179
  Direct pages reclaimed                         44881       27889       27453       34843
  Kswapd efficiency                                99%         99%         99%         99%
  Kswapd velocity                            21754.791   21675.460   21696.029   21649.127
  Direct efficiency                               100%        100%        100%        100%
  Direct velocity                               37.783      23.375      23.031      29.188
  Percentage direct scans                           0%          0%          0%          0%

ftrace showed that there was no stalling on writeback or pages submitted
for IO from reclaim context.

postmark was similar and while it was more interesting, it also did not
push reclaim heavily.

  POSTMARK
                                       3.3.0-vanilla       rc2-vanilla  lumpyremove-v2r3       nosync-v2r3
  Transactions per second:               16.00 ( 0.00%)    20.00 (25.00%)    18.00 (12.50%)    17.00 ( 6.25%)
  Data megabytes read per second:        18.80 ( 0.00%)    24.27 (29.10%)    22.26 (18.40%)    20.54 ( 9.26%)
  Data megabytes written per second:     35.83 ( 0.00%)    46.25 (29.08%)    42.42 (18.39%)    39.14 ( 9.24%)
  Files created alone per second:        28.00 ( 0.00%)    38.00 (35.71%)    34.00 (21.43%)    30.00 ( 7.14%)
  Files create/transact per second:       8.00 ( 0.00%)    10.00 (25.00%)     9.00 (12.50%)     8.00 ( 0.00%)
  Files deleted alone per second:       556.00 ( 0.00%)  1224.00 (120.14%)  3062.00 (450.72%)  6124.00 (1001.44%)
  Files delete/transact per second:       8.00 ( 0.00%)    10.00 (25.00%)     9.00 (12.50%)     8.00 ( 0.00%)

  MMTests Statistics: duration
  Sys Time Running Test (seconds)             113.34    107.99    109.73    108.72
  User+Sys Time Running Test (seconds)        145.51    139.81    143.32    143.55
  Total Elapsed Time (seconds)               1159.16    899.23    980.17   1062.27

  MMTests Statistics: vmstat
  Page Ins                                    13710192    13729032    13727944    13760136
  Page Outs                                   43071140    42987228    42733684    42931624
  Swap Ins                                           0           0           0           0
  Swap Outs                                          0           0           0           0
  Direct pages scanned                               0           0           0           0
  Kswapd pages scanned                         9941613     9937443     9939085     9929154
  Kswapd pages reclaimed                       9940926     9936751     9938397     9928465
  Direct pages reclaimed                             0           0           0           0
  Kswapd efficiency                                99%         99%         99%         99%
  Kswapd velocity                             8576.567   11051.058   10140.164    9347.109
  Direct efficiency                               100%        100%        100%        100%
  Direct velocity                                0.000       0.000       0.000       0.000

It looks like here that the full series regresses performance but as
ftrace showed no usage of wait_iff_congested() or sync reclaim I am
assuming it's a disruption due to monitoring.  Other data such as memory
usage, page IO, swap IO all looked similar.

Running a benchmark with a plain DD showed nothing very interesting.
The full series stalled in wait_iff_congested() slightly less but stall
times on vanilla kernels were marginal.

Running a benchmark that hammered on file-backed mappings showed stalls
due to congestion but not in sync writebacks

  MICRO
                                       3.3.0-vanilla       rc2-vanilla  lumpyremove-v2r3       nosync-v2r3
  MMTests Statistics: duration
  Sys Time Running Test (seconds)             308.13    294.50    298.75    299.53
  User+Sys Time Running Test (seconds)        330.45    316.28    318.93    320.79
  Total Elapsed Time (seconds)               1814.90   1833.88   1821.14   1832.91

  MMTests Statistics: vmstat
  Page Ins                                      108712      120708       97224      110344
  Page Outs                                  155514576   156017404   155813676   156193256
  Swap Ins                                           0           0           0           0
  Swap Outs                                          0           0           0           0
  Direct pages scanned                         2599253     1550480     2512822     2414760
  Kswapd pages scanned                        69742364    71150694    68839041    69692533
  Kswapd pages reclaimed                      34824488    34773341    34796602    34799396
  Direct pages reclaimed                         53693       94750       61792       75205
  Kswapd efficiency                                49%         48%         50%         49%
  Kswapd velocity                            38427.662   38797.901   37799.972   38022.889
  Direct efficiency                                 2%          6%          2%          3%
  Direct velocity                             1432.174     845.464    1379.807    1317.446
  Percentage direct scans                           3%          2%          3%          3%
  Page writes by reclaim                             0           0           0           0
  Page writes file                                   0           0           0           0
  Page writes anon                                   0           0           0           0
  Page reclaim immediate                             0           0           0        1218
  Page rescued immediate                             0           0           0           0
  Slabs scanned                                  15360       16384       13312       16384
  Direct inode steals                                0           0           0           0
  Kswapd inode steals                             4340        4327        1630        4323

  FTrace Reclaim Statistics: congestion_wait
  Direct number congest     waited                 0          0          0          0
  Direct time   congest     waited               0ms        0ms        0ms        0ms
  Direct full   congest     waited                 0          0          0          0
  Direct number conditional waited               900        870        754        789
  Direct time   conditional waited               0ms        0ms        0ms       20ms
  Direct full   conditional waited                 0          0          0          0
  KSwapd number congest     waited              2106       2308       2116       1915
  KSwapd time   congest     waited          139924ms   157832ms   125652ms   132516ms
  KSwapd full   congest     waited              1346       1530       1202       1278
  KSwapd number conditional waited             12922      16320      10943      14670
  KSwapd time   conditional waited               0ms        0ms        0ms        0ms
  KSwapd full   conditional waited                 0          0          0          0

Reclaim statistics are not radically changed.  The stall times in kswapd
are massive but it is clear that it is due to calls to congestion_wait()
and that is almost certainly the call in balance_pgdat().  Otherwise
stalls due to dirty pages are non-existant.

I ran a benchmark that stressed high-order allocation.  This is very
artifical load but was used in the past to evaluate lumpy reclaim and
compaction.  Generally I look at allocation success rates and latency
figures.

  STRESS-HIGHALLOC
                   3.3.0-vanilla       rc2-vanilla  lumpyremove-v2r3       nosync-v2r3
  Pass 1          81.00 ( 0.00%)    28.00 (-53.00%)    24.00 (-57.00%)    28.00 (-53.00%)
  Pass 2          82.00 ( 0.00%)    39.00 (-43.00%)    38.00 (-44.00%)    43.00 (-39.00%)
  while Rested    88.00 ( 0.00%)    87.00 (-1.00%)    88.00 ( 0.00%)    88.00 ( 0.00%)

  MMTests Statistics: duration
  Sys Time Running Test (seconds)             740.93    681.42    685.14    684.87
  User+Sys Time Running Test (seconds)       2922.65   3269.52   3281.35   3279.44
  Total Elapsed Time (seconds)               1161.73   1152.49   1159.55   1161.44

  MMTests Statistics: vmstat
  Page Ins                                     4486020     2807256     2855944     2876244
  Page Outs                                    7261600     7973688     7975320     7986120
  Swap Ins                                       31694           0           0           0
  Swap Outs                                      98179           0           0           0
  Direct pages scanned                           53494       57731       34406      113015
  Kswapd pages scanned                         6271173     1287481     1278174     1219095
  Kswapd pages reclaimed                       2029240     1281025     1260708     1201583
  Direct pages reclaimed                          1468       14564       16649       92456
  Kswapd efficiency                                32%         99%         98%         98%
  Kswapd velocity                             5398.133    1117.130    1102.302    1049.641
  Direct efficiency                                 2%         25%         48%         81%
  Direct velocity                               46.047      50.092      29.672      97.306
  Percentage direct scans                           0%          4%          2%          8%
  Page writes by reclaim                       1616049           0           0           0
  Page writes file                             1517870           0           0           0
  Page writes anon                               98179           0           0           0
  Page reclaim immediate                        103778       27339        9796       17831
  Page rescued immediate                             0           0           0           0
  Slabs scanned                                1096704      986112      980992      998400
  Direct inode steals                              223      215040      216736      247881
  Kswapd inode steals                           175331       61548       68444       63066
  Kswapd skipped wait                            21991           0           1           0
  THP fault alloc                                    1         135         125         134
  THP collapse alloc                               393         311         228         236
  THP splits                                        25          13           7           8
  THP fault fallback                                 0           0           0           0
  THP collapse fail                                  3           5           7           7
  Compaction stalls                                865        1270        1422        1518
  Compaction success                               370         401         353         383
  Compaction failures                              495         869        1069        1135
  Compaction pages moved                        870155     3828868     4036106     4423626
  Compaction move failure                        26429       23865       29742       27514

Success rates are completely hosed for 3.4-rc2 which is almost certainly
due to commit fe2c2a1066 ("vmscan: reclaim at order 0 when compaction
is enabled").  I expected this would happen for kswapd and impair
allocation success rates (https://lkml.org/lkml/2012/1/25/166) but I did
not anticipate this much a difference: 80% less scanning, 37% less
reclaim by kswapd

In comparison, reclaim/compaction is not aggressive and gives up easily
which is the intended behaviour.  hugetlbfs uses __GFP_REPEAT and would
be much more aggressive about reclaim/compaction than THP allocations
are.  The stress test above is allocating like neither THP or hugetlbfs
but is much closer to THP.

Mainline is now impaired in terms of high order allocation under heavy
load although I do not know to what degree as I did not test with
__GFP_REPEAT.  Keep this in mind for bugs related to hugepage pool
resizing, THP allocation and high order atomic allocation failures from
network devices.

In terms of congestion throttling, I see the following for this test

  FTrace Reclaim Statistics: congestion_wait
  Direct number congest     waited                 3          0          0          0
  Direct time   congest     waited               0ms        0ms        0ms        0ms
  Direct full   congest     waited                 0          0          0          0
  Direct number conditional waited               957        512       1081       1075
  Direct time   conditional waited               0ms        0ms        0ms        0ms
  Direct full   conditional waited                 0          0          0          0
  KSwapd number congest     waited                36          4          3          5
  KSwapd time   congest     waited            3148ms      400ms      300ms      500ms
  KSwapd full   congest     waited                30          4          3          5
  KSwapd number conditional waited             88514        197        332        542
  KSwapd time   conditional waited            4980ms        0ms        0ms        0ms
  KSwapd full   conditional waited                49          0          0          0

The "conditional waited" times are the most interesting as this is
directly impacted by the number of dirty pages encountered during scan.
As lumpy reclaim is no longer scanning contiguous ranges, it is finding
fewer dirty pages.  This brings wait times from about 5 seconds to 0.
kswapd itself is still calling congestion_wait() so it'll still stall but
it's a lot less.

In terms of the type of IO we were doing, I see this

  FTrace Reclaim Statistics: mm_vmscan_writepage
  Direct writes anon  sync                         0          0          0          0
  Direct writes anon  async                        0          0          0          0
  Direct writes file  sync                         0          0          0          0
  Direct writes file  async                        0          0          0          0
  Direct writes mixed sync                         0          0          0          0
  Direct writes mixed async                        0          0          0          0
  KSwapd writes anon  sync                         0          0          0          0
  KSwapd writes anon  async                    91682          0          0          0
  KSwapd writes file  sync                         0          0          0          0
  KSwapd writes file  async                   822629          0          0          0
  KSwapd writes mixed sync                         0          0          0          0
  KSwapd writes mixed async                        0          0          0          0

In 3.2, kswapd was doing a bunch of async writes of pages but
reclaim/compaction was never reaching a point where it was doing sync
IO.  This does not guarantee that reclaim/compaction was not calling
wait_on_page_writeback() but I would consider it unlikely.  It indicates
that merging patches 2 and 3 to stop reclaim/compaction calling
wait_on_page_writeback() should be safe.

This patch:

Lumpy reclaim had a purpose but in the mind of some, it was to kick the
system so hard it trashed.  For others the purpose was to complicate
vmscan.c.  Over time it was giving softer shoes and a nicer attitude but
memory compaction needs to step up and replace it so this patch sends
lumpy reclaim to the farm.

The tracepoint format changes for isolating LRU pages with this patch
applied.  Furthermore reclaim/compaction can no longer queue dirty pages
in pageout() if the underlying BDI is congested.  Lumpy reclaim used
this logic and reclaim/compaction was using it in error.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ying Han <yinghan@google.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:19 -07:00
Rik van Riel e709ffd616 mm: remove swap token code
The swap token code no longer fits in with the current VM model.  It
does not play well with cgroups or the better NUMA placement code in
development, since we have only one swap token globally.

It also has the potential to mess with scalability of the system, by
increasing the number of non-reclaimable pages on the active and
inactive anon LRU lists.

Last but not least, the swap token code has been broken for a year
without complaints, as reported by Konstantin Khlebnikov.  This suggests
we no longer have much use for it.

The days of sub-1G memory systems with heavy use of swap are over.  If
we ever need thrashing reducing code in the future, we will have to
implement something that does scale.

Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Bob Picco <bpicco@meloft.net>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:19 -07:00
Linus Torvalds 90324cc1b1 avoid iput() from flusher thread
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Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux

Pull writeback tree from Wu Fengguang:
 "Mainly from Jan Kara to avoid iput() in the flusher threads."

* tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Avoid iput() from flusher thread
  vfs: Rename end_writeback() to clear_inode()
  vfs: Move waiting for inode writeback from end_writeback() to evict_inode()
  writeback: Refactor writeback_single_inode()
  writeback: Remove wb->list_lock from writeback_single_inode()
  writeback: Separate inode requeueing after writeback
  writeback: Move I_DIRTY_PAGES handling
  writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()
  writeback: Move clearing of I_SYNC into inode_sync_complete()
  writeback: initialize global_dirty_limit
  fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds
  mm: page-writeback.c: local functions should not be exposed globally
2012-05-28 09:54:45 -07:00
Linus Torvalds ece78b7df7 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull ext2, ext3 and quota fixes from Jan Kara:
 "Interesting bits are:
   - removal of a special i_mutex locking subclass (I_MUTEX_QUOTA) since
     quota code does not need i_mutex anymore in any unusual way.
   - backport (from ext4) of a fix of a checkpointing bug (missing cache
     flush) that could lead to fs corruption on power failure

  The rest are just random small fixes & cleanups."

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  ext2: trivial fix to comment for ext2_free_blocks
  ext2: remove the redundant comment for ext2_export_ops
  ext3: return 32/64-bit dir name hash according to usage type
  quota: Get rid of nested I_MUTEX_QUOTA locking subclass
  quota: Use precomputed value of sb_dqopt in dquot_quota_sync
  ext2: Remove i_mutex use from ext2_quota_write()
  reiserfs: Remove i_mutex use from reiserfs_quota_write()
  ext4: Remove i_mutex use from ext4_quota_write()
  ext3: Remove i_mutex use from ext3_quota_write()
  quota: Fix double lock in add_dquot_ref() with CONFIG_QUOTA_DEBUG
  jbd: Write journal superblock with WRITE_FUA after checkpointing
  jbd: protect all log tail updates with j_checkpoint_mutex
  jbd: Split updating of journal superblock and marking journal empty
  ext2: do not register write_super within VFS
  ext2: Remove s_dirt handling
  ext2: write superblock only once on unmount
  ext3: update documentation with barrier=1 default
  ext3: remove max_debt in find_group_orlov()
  jbd: Refine commit writeout logic
2012-05-25 08:14:59 -07:00
Linus Torvalds 644473e9c6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace enhancements from Eric Biederman:
 "This is a course correction for the user namespace, so that we can
  reach an inexpensive, maintainable, and reasonably complete
  implementation.

  Highlights:
   - Config guards make it impossible to enable the user namespace and
     code that has not been converted to be user namespace safe.

   - Use of the new kuid_t type ensures the if you somehow get past the
     config guards the kernel will encounter type errors if you enable
     user namespaces and attempt to compile in code whose permission
     checks have not been updated to be user namespace safe.

   - All uids from child user namespaces are mapped into the initial
     user namespace before they are processed.  Removing the need to add
     an additional check to see if the user namespace of the compared
     uids remains the same.

   - With the user namespaces compiled out the performance is as good or
     better than it is today.

   - For most operations absolutely nothing changes performance or
     operationally with the user namespace enabled.

   - The worst case performance I could come up with was timing 1
     billion cache cold stat operations with the user namespace code
     enabled.  This went from 156s to 164s on my laptop (or 156ns to
     164ns per stat operation).

   - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value.
     Most uid/gid setting system calls treat these value specially
     anyway so attempting to use -1 as a uid would likely cause
     entertaining failures in userspace.

   - If setuid is called with a uid that can not be mapped setuid fails.
     I have looked at sendmail, login, ssh and every other program I
     could think of that would call setuid and they all check for and
     handle the case where setuid fails.

   - If stat or a similar system call is called from a context in which
     we can not map a uid we lie and return overflowuid.  The LFS
     experience suggests not lying and returning an error code might be
     better, but the historical precedent with uids is different and I
     can not think of anything that would break by lying about a uid we
     can't map.

   - Capabilities are localized to the current user namespace making it
     safe to give the initial user in a user namespace all capabilities.

  My git tree covers all of the modifications needed to convert the core
  kernel and enough changes to make a system bootable to runlevel 1."

Fix up trivial conflicts due to nearby independent changes in fs/stat.c

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
  userns:  Silence silly gcc warning.
  cred: use correct cred accessor with regards to rcu read lock
  userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq
  userns: Convert cgroup permission checks to use uid_eq
  userns: Convert tmpfs to use kuid and kgid where appropriate
  userns: Convert sysfs to use kgid/kuid where appropriate
  userns: Convert sysctl permission checks to use kuid and kgids.
  userns: Convert proc to use kuid/kgid where appropriate
  userns: Convert ext4 to user kuid/kgid where appropriate
  userns: Convert ext3 to use kuid/kgid where appropriate
  userns: Convert ext2 to use kuid/kgid where appropriate.
  userns: Convert devpts to use kuid/kgid where appropriate
  userns: Convert binary formats to use kuid/kgid where appropriate
  userns: Add negative depends on entries to avoid building code that is userns unsafe
  userns: signal remove unnecessary map_cred_ns
  userns: Teach inode_capable to understand inodes whose uids map to other namespaces.
  userns: Fail exec for suid and sgid binaries with ids outside our user namespace.
  userns: Convert stat to return values mapped from kuids and kgids
  userns: Convert user specfied uids and gids in chown into kuids and kgid
  userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
  ...
2012-05-23 17:42:39 -07:00
Linus Torvalds 468f4d1a85 Power management updates for 3.5
* Implementation of opportunistic suspend (autosleep) and user space interface
   for manipulating wakeup sources.
 
 * Hibernate updates from Bojan Smojver and Minho Ban.
 
 * Updates of the runtime PM core and generic PM domains framework related to
   PM QoS.
 
 * Assorted fixes.
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Merge tag 'pm-for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:

 - Implementation of opportunistic suspend (autosleep) and user space
   interface for manipulating wakeup sources.

 - Hibernate updates from Bojan Smojver and Minho Ban.

 - Updates of the runtime PM core and generic PM domains framework
   related to PM QoS.

 - Assorted fixes.

* tag 'pm-for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits)
  epoll: Fix user space breakage related to EPOLLWAKEUP
  PM / Domains: Make it possible to add devices to inactive domains
  PM / Hibernate: Use get_gendisk to verify partition if resume_file is integer format
  PM / Domains: Fix computation of maximum domain off time
  PM / Domains: Fix link checking when add subdomain
  PM / Sleep: User space wakeup sources garbage collector Kconfig option
  PM / Sleep: Make the limit of user space wakeup sources configurable
  PM / Documentation: suspend-and-cpuhotplug.txt: Fix typo
  PM / Domains: Cache device stop and domain power off governor results, v3
  PM / Domains: Make device removal more straightforward
  PM / Sleep: Fix a mistake in a conditional in autosleep_store()
  epoll: Add a flag, EPOLLWAKEUP, to prevent suspend while epoll events are ready
  PM / QoS: Create device constraints objects on notifier registration
  PM / Runtime: Remove device fields related to suspend time, v2
  PM / Domains: Rework default domain power off governor function, v2
  PM / Domains: Rework default device stop governor function, v2
  PM / Sleep: Add user space interface for manipulating wakeup sources, v3
  PM / Sleep: Add "prevent autosleep time" statistics to wakeup sources
  PM / Sleep: Implement opportunistic sleep, v2
  PM / Sleep: Add wakeup_source_activate and wakeup_source_deactivate tracepoints
  ...
2012-05-23 14:07:06 -07:00
Linus Torvalds 2e341ca686 Sound updates for 3.5-rc1
This is the first big chunk for 3.5 merges of sound stuff.
 There are a few big changes in different areas.  First off, the
 streaming logic of USB-audio endpoints has been largely rewritten
 for the better support of "implicit feedback".  If anything about USB
 got broken, this change has to be checked.
 
 For HD-audio, the resume procedure was changed; instead of delaying
 the resume of the hardware until the first use, now waking up immediately
 at resume.  This is for buggy BIOS.
 
 For ASoC, dynamic PCM support and the improved support for digital links
 between off-SoC devices are major framework changes.
 
 Some highlights are below:
 
 * HD-audio
 - Avoid the accesses of invalid pin-control bits that may stall the codec
 - V-ref setup cleanups
 - Fix the races in power-saving code
 - Fix the races in codec cache hashes and connection lists
 - Split some common codes for BIOS auto-parser to hda_auto_parser.c
 - Changed the PM resume code to wake up immediately for buggy BIOS
 - Creative SoundCore3D support
 - Add Conexant CX20751/2/3/4 codec support
 
 * ASoC
 - Dynamic PCM support, allowing support for SoCs with internal routing
   through components with tight sequencing and formatting constraints
   within their internal paths or where there are multiple components
   connected with CPU managed DMA controllers inside the SoC.
 - Greatly improved support for direct digital links between off-SoC
   devices, providing a much simpler way of connecting things like digital
   basebands to CODECs.
 - Much more fine grained and robust locking, cleaning up some of the
   confusion that crept in with multi-component.
 - CPU support for nVidia Tegra 30 I2S and audio hub controllers and
   ST-Ericsson MSP I2S controolers
 - New CODEC drivers for Cirrus CS42L52, LAPIS Semiconductor ML26124, Texas
   Instruments LM49453.
 - Some regmap changes needed by the Tegra I2S driver.
 - mc13783 audio support.
 
 * Misc
 - Rewrite with module_pci_driver()
 - Xonar DGX support for snd-oxygen
 - Improvement of packet handling in snd-firewire driver
 - New USB-endpoint streaming logic
 - Enhanced M-audio FTU quirks and relevant cleanups
 - Increment the support of OSS devices to 256
 - snd-aloop accuracy improvement
 
 There are a few more pending changes for 3.5, but they will be
 sent slightly later as partly depending on the changes of DRM.
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Merge tag 'sound-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

Pull sound updates from Takashi Iwai:
 "This is the first big chunk for 3.5 merges of sound stuff.

  There are a few big changes in different areas.  First off, the
  streaming logic of USB-audio endpoints has been largely rewritten for
  the better support of "implicit feedback".  If anything about USB got
  broken, this change has to be checked.

  For HD-audio, the resume procedure was changed; instead of delaying
  the resume of the hardware until the first use, now waking up
  immediately at resume.  This is for buggy BIOS.

  For ASoC, dynamic PCM support and the improved support for digital
  links between off-SoC devices are major framework changes.

  Some highlights are below:

  * HD-audio
   - Avoid accesses of invalid pin-control bits that may stall the codec
   - V-ref setup cleanups
   - Fix the races in power-saving code
   - Fix the races in codec cache hashes and connection lists
   - Split some common codes for BIOS auto-parser to hda_auto_parser.c
   - Changed the PM resume code to wake up immediately for buggy BIOS
   - Creative SoundCore3D support
   - Add Conexant CX20751/2/3/4 codec support

  * ASoC
   - Dynamic PCM support, allowing support for SoCs with internal
     routing through components with tight sequencing and formatting
     constraints within their internal paths or where there are multiple
     components connected with CPU managed DMA controllers inside the
     SoC.
   - Greatly improved support for direct digital links between off-SoC
     devices, providing a much simpler way of connecting things like
     digital basebands to CODECs.
   - Much more fine grained and robust locking, cleaning up some of the
     confusion that crept in with multi-component.
   - CPU support for nVidia Tegra 30 I2S and audio hub controllers and
     ST-Ericsson MSP I2S controolers
   - New CODEC drivers for Cirrus CS42L52, LAPIS Semiconductor ML26124,
     Texas Instruments LM49453.
   - Some regmap changes needed by the Tegra I2S driver.
   - mc13783 audio support.

  * Misc
   - Rewrite with module_pci_driver()
   - Xonar DGX support for snd-oxygen
   - Improvement of packet handling in snd-firewire driver
   - New USB-endpoint streaming logic
   - Enhanced M-audio FTU quirks and relevant cleanups
   - Increment the support of OSS devices to 256
   - snd-aloop accuracy improvement

  There are a few more pending changes for 3.5, but they will be sent
  slightly later as partly depending on the changes of DRM."

Fix up conflicts in regmap (due to duplicate patches, with some further
updates then having already come in from the regmap tree).  Also some
fairly trivial context conflicts in the imx and mcx soc drivers.

* tag 'sound-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (280 commits)
  ALSA: snd-usb: fix stream info output in /proc
  ALSA: pcm - Add proper state checks to snd_pcm_drain()
  ALSA: sh: Fix up namespace collision in sh_dac_audio.
  ALSA: hda/realtek - Fix unused variable compile warning
  ASoC: sh: fsi: enable chip specific data transfer mode
  ASoC: sh: fsi: call fsi_hw_startup/shutdown from fsi_dai_trigger()
  ASoC: sh: fsi: use same format for IN/OUT
  ASoC: sh: fsi: add fsi_version() and removed meaningless version check
  ASoC: sh: fsi: use register field macro name on IN/OUT_DMAC
  ASoC: tegra: Add machine driver for WM8753 codec
  ALSA: hda - Fix possible races of accesses to connection list array
  ASoC: OMAP: HDMI: Introduce codec
  ARM: mx31_3ds: Add sound support
  ASoC: imx-mc13783 cleanup
  mx31moboard: Add sound support
  ASoC: mc13783 codec cleanups
  ASoC: add imx-mc13783 sound support
  ASoC: Add mc13783 codec
  mfd: mc13xxx: add codec platform data
  ASoC: don't flip master of DT-instantiated DAI links
  ...
2012-05-23 13:05:43 -07:00
Linus Torvalds e8650a0823 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial updates from Jiri Kosina:
 "As usual, it's mostly typo fixes, redundant code elimination and some
  documentation updates."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (57 commits)
  edac, mips: don't change code that has been removed in edac/mips tree
  xtensa: Change mail addresses of Hannes Weiner and Oskar Schirmer
  lib: Change mail address of Oskar Schirmer
  net: Change mail address of Oskar Schirmer
  arm/m68k: Change mail address of Sebastian Hess
  i2c: Change mail address of Oskar Schirmer
  net: Fix tcp_build_and_update_options comment in struct tcp_sock
  atomic64_32.h: fix parameter naming mismatch
  Kconfig: replace "--- help ---" with "---help---"
  c2port: fix bogus Kconfig "default no"
  edac: Fix spelling errors.
  qla1280: Remove redundant NULL check before release_firmware() call
  remoteproc: remove redundant NULL check before release_firmware()
  qla2xxx: Remove redundant NULL check before release_firmware() call.
  aic94xx: Get rid of redundant NULL check before release_firmware() call
  tehuti: delete redundant NULL check before release_firmware()
  qlogic: get rid of a redundant test for NULL before call to release_firmware()
  bna: remove redundant NULL test before release_firmware()
  tg3: remove redundant NULL test before release_firmware() call
  typhoon: get rid of redundant conditional before all to release_firmware()
  ...
2012-05-22 19:22:50 -07:00
Eric W. Biederman 08cefc7ab8 userns: Convert ext4 to user kuid/kgid where appropriate
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-05-15 14:59:27 -07:00
Eric W. Biederman 1523299d58 userns: Convert ext3 to use kuid/kgid where appropriate
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-05-15 14:59:27 -07:00
Jan Kara fd2cbd4dfa jbd: Write journal superblock with WRITE_FUA after checkpointing
If journal superblock is written only in disk's caches and other transaction
starts reusing space of the transaction cleaned from the log, it can happen
blocks of a new transaction reach the disk before journal superblock. When
power failure happens in such case, subsequent journal replay would still try
to replay the old transaction but some of it's blocks may be already
overwritten by the new transaction. For this reason we must use WRITE_FUA when
updating log tail and we must first write new log tail to disk and update
in-memory information only after that.

Signed-off-by: Jan Kara <jack@suse.cz>
2012-05-15 23:34:37 +02:00
Jan Kara 9754e39c7b jbd: Split updating of journal superblock and marking journal empty
There are three case of updating journal superblock. In the first case, we want
to mark journal as empty (setting s_sequence to 0), in the second case we want
to update log tail, in the third case we want to update s_errno. Split these
cases into separate functions. It makes the code slightly more straightforward
and later patches will make the distinction even more important.

Signed-off-by: Jan Kara <jack@suse.cz>
2012-05-15 23:34:36 +02:00
Paul E. McKenney 21e52e1566 rcu: Make RCU_FAST_NO_HZ handle timer migration
The current RCU_FAST_NO_HZ assumes that timers do not migrate unless a
CPU goes offline, in which case it assumes that the CPU will have to come
out of dyntick-idle mode (cancelling the timer) in order to go offline.
This is important because when RCU_FAST_NO_HZ permits a CPU to enter
dyntick-idle mode despite having RCU callbacks pending, it posts a timer
on that CPU to force a wakeup on that CPU.  This wakeup ensures that the
CPU will eventually handle the end of the grace period, including invoking
its RCU callbacks.

However, Pascal Chapperon's test setup shows that the timer handler
rcu_idle_gp_timer_func() really does get invoked in some cases.  This is
problematic because this can cause the CPU that entered dyntick-idle
mode despite still having RCU callbacks pending to remain in
dyntick-idle mode indefinitely, which means that its RCU callbacks might
never be invoked.  This situation can result in grace-period delays or
even system hangs, which matches Pascal's observations of slow boot-up
and shutdown (https://lkml.org/lkml/2012/4/5/142).  See also the bugzilla:

	https://bugzilla.redhat.com/show_bug.cgi?id=806548

This commit therefore causes the "should never be invoked" timer handler
rcu_idle_gp_timer_func() to use smp_call_function_single() to wake up
the CPU for which the timer was intended, allowing that CPU to invoke
its RCU callbacks in a timely manner.

Reported-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-05-09 14:26:56 -07:00
Jan Kara cc1676d917 writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()
When writeback_single_inode() is called on inode which has I_SYNC already
set while doing WB_SYNC_NONE, inode is moved to b_more_io list. However
this makes sense only if the caller is flusher thread. For other callers of
writeback_single_inode() it doesn't really make sense and may be even wrong
- flusher thread may be doing WB_SYNC_ALL writeback in parallel.

So we move requeueing from writeback_single_inode() to writeback_sb_inodes().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
2012-05-06 13:43:38 +08:00
Arve Hjønnevåg 6791e36c4a PM / Sleep: Add wakeup_source_activate and wakeup_source_deactivate tracepoints
Add tracepoints to wakeup_source_activate and wakeup_source_deactivate.
Useful for checking that specific wakeup sources overlap as expected.

Signed-off-by: Arve Hjønnevåg <arve@android.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-05-01 21:25:25 +02:00
Paul E. McKenney 2fdbb31b66 rcu: Add RCU_FAST_NO_HZ tracing for idle exit
Traces of rcu_prep_idle events can be confusing because
rcu_cleanup_after_idle() does no tracing.  This commit therefore adds
this tracing.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-04-24 20:55:19 -07:00
Liam Girdwood c97f3bdd26 ASoC: dapm: Fix x86_64 build warning.
Fixes the following build warning on x86_64.

In file included from include/trace/ftrace.h:567:0,
                 from include/trace/define_trace.h:86,
                 from include/trace/events/asoc.h:410,
                 from sound/soc/soc-core.c:45:
include/trace/events/asoc.h: In function 'ftrace_raw_event_snd_soc_dapm_output_path':
include/trace/events/asoc.h:246:1: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
include/trace/events/asoc.h: In function 'ftrace_raw_event_snd_soc_dapm_input_path':
include/trace/events/asoc.h:275:1: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]

Signed-off-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-04-23 13:15:35 +01:00
Liam Girdwood ec2e3031b6 ASoC: dapm: Add API call to query valid DAPM paths
In preparation for ASoC DSP support.

Add a DAPM API call to determine whether a DAPM audio path is valid between
source and sink widgets. This also takes into account all kcontrol mux and mixer
settings in between the source and sink widgets to validate the audio path.

This will be used by the DSP core to determine the runtime DAI mappings
between FE and BE DAIs in order to run PCM operations.

Signed-off-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-04-18 18:23:00 +01:00
Jan Kara 2db938bee3 jbd: Refine commit writeout logic
Currently we write out all journal buffers in WRITE_SYNC mode. This improves
performance for fsync heavy workloads but hinders performance when writes
are mostly asynchronous, most noticably it slows down readers and users
complain about slow desktop response etc.

So submit writes as asynchronous in the normal case and only submit writes as
WRITE_SYNC if we detect someone is waiting for current transaction commit.

I've gathered some numbers to back this change. The first is the read latency
test. It measures time to read 1 MB after several seconds of sleeping in
presence of streaming writes.

Top 10 times (out of 90) in us:
Before		After
2131586		697473
1709932		557487
1564598		535642
1480462		347573
1478579		323153
1408496		222181
1388960		181273
1329565		181070
1252486		172832
1223265		172278

Average:
619377		82180

So the improvement in both maximum and average latency is massive.

I've measured fsync throughput by:
fs_mark -n 100 -t 1 -s 16384 -d /mnt/fsync/ -S 1 -L 4

in presence of streaming reader. The numbers (fsyncs/s) are:
Before		After
9.9		6.3
6.8		6.0
6.3		6.2
5.8		6.1

So fsync performance seems unharmed by this change.

Signed-off-by: Jan Kara <jack@suse.cz>
2012-04-11 11:12:44 +02:00
Stephen Boyd b3aa1584e9 workqueue: Fix workqueue_execute_end() comment
workqueue_execute_end() is called after the callback function,
not before.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-04-10 10:49:47 +02:00
Linus Torvalds 66cfb32772 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar.

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/p4: Add format attributes
  tracing, sched, vfs: Fix 'old_pid' usage in trace_sched_process_exec()
2012-04-04 10:04:42 -07:00
Oleg Nesterov 6308191f6f tracing, sched, vfs: Fix 'old_pid' usage in trace_sched_process_exec()
1. TRACE_EVENT(sched_process_exec) forgets to actually use the
   old pid argument, it sets ->old_pid = p->pid.

2. search_binary_handler() uses the wrong pid number. tracepoint
   needs the global pid_t from the root namespace, while old_pid
   is the virtual pid number as it seen by the tracer/parent.

With this patch we have two pid_t's in search_binary_handler(),
not really nice. Perhaps we should switch to "struct pid*", but
in this case it would be better to cleanup the current code
first and move the "depth == 0" code outside.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Smith <dsmith@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Link: http://lkml.kernel.org/r/20120330162636.GA4857@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-03-31 11:53:22 +02:00
Linus Torvalds 9613bebb22 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes and features from Chris Mason:
 "We've merged in the error handling patches from SuSE.  These are
  already shipping in the sles kernel, and they give btrfs the ability
  to abort transactions and go readonly on errors.  It involves a lot of
  churn as they clarify BUG_ONs, and remove the ones we now properly
  deal with.

  Josef reworked the way our metadata interacts with the page cache.
  page->private now points to the btrfs extent_buffer object, which
  makes everything faster.  He changed it so we write an whole extent
  buffer at a time instead of allowing individual pages to go down,,
  which will be important for the raid5/6 code (for the 3.5 merge
  window ;)

  Josef also made us more aggressive about dropping pages for metadata
  blocks that were freed due to COW.  Overall, our metadata caching is
  much faster now.

  We've integrated my patch for metadata bigger than the page size.
  This allows metadata blocks up to 64KB in size.  In practice 16K and
  32K seem to work best.  For workloads with lots of metadata, this cuts
  down the size of the extent allocation tree dramatically and fragments
  much less.

  Scrub was updated to support the larger block sizes, which ended up
  being a fairly large change (thanks Stefan Behrens).

  We also have an assortment of fixes and updates, especially to the
  balancing code (Ilya Dryomov), the back ref walker (Jan Schmidt) and
  the defragging code (Liu Bo)."

Fixed up trivial conflicts in fs/btrfs/scrub.c that were just due to
removal of the second argument to k[un]map_atomic() in commit
7ac687d9e0.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (75 commits)
  Btrfs: update the checks for mixed block groups with big metadata blocks
  Btrfs: update to the right index of defragment
  Btrfs: do not bother to defrag an extent if it is a big real extent
  Btrfs: add a check to decide if we should defrag the range
  Btrfs: fix recursive defragment with autodefrag option
  Btrfs: fix the mismatch of page->mapping
  Btrfs: fix race between direct io and autodefrag
  Btrfs: fix deadlock during allocating chunks
  Btrfs: show useful info in space reservation tracepoint
  Btrfs: don't use crc items bigger than 4KB
  Btrfs: flush out and clean up any block device pages during mount
  btrfs: disallow unequal data/metadata blocksize for mixed block groups
  Btrfs: enhance superblock sanity checks
  Btrfs: change scrub to support big blocks
  Btrfs: minor cleanup in scrub
  Btrfs: introduce common define for max number of mirrors
  Btrfs: fix infinite loop in btrfs_shrink_device()
  Btrfs: fix memory leak in resolver code
  Btrfs: allow dup for data chunks in mixed mode
  Btrfs: validate target profiles only if we are going to use them
  ...
2012-03-30 12:44:29 -07:00
Linus Torvalds 69e1aaddd6 Ext4 commits for 3.3 merge window; mostly cleanups and bug fixes
The changes to export dirty_writeback_interval are from Artem's s_dirt
 cleanup patch series.  The same is true of the change to remove the
 s_dirt helper functions which never got used by anyone in-tree.  I've
 run these changes by Al Viro, and am carrying them so that Artem can
 more easily fix up the rest of the file systems during the next merge
 window.  (Originally we had hopped to remove the use of s_dirt from
 ext4 during this merge window, but his patches had some bugs, so I
 ultimately ended dropping them from the ext4 tree.)
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates for 3.4 from Ted Ts'o:
 "Ext4 commits for 3.3 merge window; mostly cleanups and bug fixes

  The changes to export dirty_writeback_interval are from Artem's s_dirt
  cleanup patch series.  The same is true of the change to remove the
  s_dirt helper functions which never got used by anyone in-tree.  I've
  run these changes by Al Viro, and am carrying them so that Artem can
  more easily fix up the rest of the file systems during the next merge
  window.  (Originally we had hopped to remove the use of s_dirt from
  ext4 during this merge window, but his patches had some bugs, so I
  ultimately ended dropping them from the ext4 tree.)"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (66 commits)
  vfs: remove unused superblock helpers
  mm: export dirty_writeback_interval
  ext4: remove useless s_dirt assignment
  ext4: write superblock only once on unmount
  ext4: do not mark superblock as dirty unnecessarily
  ext4: correct ext4_punch_hole return codes
  ext4: remove restrictive checks for EOFBLOCKS_FL
  ext4: always set then trimmed blocks count into len
  ext4: fix trimmed block count accunting
  ext4: fix start and len arguments handling in ext4_trim_fs()
  ext4: update s_free_{inodes,blocks}_count during online resize
  ext4: change some printk() calls to use ext4_msg() instead
  ext4: avoid output message interleaving in ext4_error_<foo>()
  ext4: remove trailing newlines from ext4_msg() and ext4_error() messages
  ext4: add no_printk argument validation, fix fallout
  ext4: remove redundant "EXT4-fs: " from uses of ext4_msg
  ext4: give more helpful error message in ext4_ext_rm_leaf()
  ext4: remove unused code from ext4_ext_map_blocks()
  ext4: rewrite punch hole to use ext4_ext_remove_space()
  jbd2: cleanup journal tail after transaction commit
  ...
2012-03-28 10:02:55 -07:00
Linus Torvalds 250f6715a4 The following text was taken from the original review request:
"[RFC PATCH 0/2] audit of linux/device.h users in include/*"
 		https://lkml.org/lkml/2012/3/4/159
 --
 
 Nearly every subsystem has some kind of header with a proto like:
 
 	void foo(struct device *dev);
 
 and yet there is no reason for most of these guys to care about the
 sub fields within the device struct.  This allows us to significantly
 reduce the scope of headers including headers.  For this instance, a
 reduction of about 40% is achieved by replacing the include with the
 simple fact that the device is some kind of a struct.
 
 Unlike the much larger module.h cleanup, this one is simply two
 commits.  One to fix the implicit <linux/device.h> users, and then
 one to delete the device.h includes from the linux/include/ dir
 wherever possible.
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Merge tag 'device-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

Pull <linux/device.h> avoidance patches from Paul Gortmaker:
 "Nearly every subsystem has some kind of header with a proto like:

	void foo(struct device *dev);

  and yet there is no reason for most of these guys to care about the
  sub fields within the device struct.  This allows us to significantly
  reduce the scope of headers including headers.  For this instance, a
  reduction of about 40% is achieved by replacing the include with the
  simple fact that the device is some kind of a struct.

  Unlike the much larger module.h cleanup, this one is simply two
  commits.  One to fix the implicit <linux/device.h> users, and then one
  to delete the device.h includes from the linux/include/ dir wherever
  possible."

* tag 'device-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
  device.h: audit and cleanup users in main include dir
  device.h: cleanup users outside of linux/include (C files)
2012-03-24 10:41:37 -07:00
Linus Torvalds f63d395d47 NFS client updates for Linux 3.4
New features include:
 - Add NFS client support for containers.
   This should enable most of the necessary functionality, including
   lockd support, and support for rpc.statd, NFSv4 idmapper and
   RPCSEC_GSS upcalls into the correct network namespace from
   which the mount system call was issued.
 - NFSv4 idmapper scalability improvements
   Base the idmapper cache on the keyring interface to allow concurrent
   access to idmapper entries. Start the process of migrating users from
   the single-threaded daemon-based approach to the multi-threaded
   request-key based approach.
 - NFSv4.1 implementation id.
   Allows the NFSv4.1 client and server to mutually identify each other
   for logging and debugging purposes.
 - Support the 'vers=4.1' mount option for mounting NFSv4.1 instead of
   having to use the more counterintuitive 'vers=4,minorversion=1'.
 - SUNRPC tracepoints.
   Start the process of adding tracepoints in order to improve debugging
   of the RPC layer.
 - pNFS object layout support for autologin.
 
 Important bugfixes include:
 - Fix a bug in rpc_wake_up/rpc_wake_up_status that caused them to fail
   to wake up all tasks when applied to priority waitqueues.
 - Ensure that we handle read delegations correctly, when we try to
   truncate a file.
 - A number of fixes for NFSv4 state manager loops (mostly to do with
   delegation recovery).
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Merge tag 'nfs-for-3.4-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates for Linux 3.4 from Trond Myklebust:
 "New features include:
   - Add NFS client support for containers.

     This should enable most of the necessary functionality, including
     lockd support, and support for rpc.statd, NFSv4 idmapper and
     RPCSEC_GSS upcalls into the correct network namespace from which
     the mount system call was issued.

   - NFSv4 idmapper scalability improvements

     Base the idmapper cache on the keyring interface to allow
     concurrent access to idmapper entries.  Start the process of
     migrating users from the single-threaded daemon-based approach to
     the multi-threaded request-key based approach.

   - NFSv4.1 implementation id.

     Allows the NFSv4.1 client and server to mutually identify each
     other for logging and debugging purposes.

   - Support the 'vers=4.1' mount option for mounting NFSv4.1 instead of
     having to use the more counterintuitive 'vers=4,minorversion=1'.

   - SUNRPC tracepoints.

     Start the process of adding tracepoints in order to improve
     debugging of the RPC layer.

   - pNFS object layout support for autologin.

  Important bugfixes include:

   - Fix a bug in rpc_wake_up/rpc_wake_up_status that caused them to
     fail to wake up all tasks when applied to priority waitqueues.

   - Ensure that we handle read delegations correctly, when we try to
     truncate a file.

   - A number of fixes for NFSv4 state manager loops (mostly to do with
     delegation recovery)."

* tag 'nfs-for-3.4-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (224 commits)
  NFS: fix sb->s_id in nfs debug prints
  xprtrdma: Remove assumption that each segment is <= PAGE_SIZE
  xprtrdma: The transport should not bug-check when a dup reply is received
  pnfs-obj: autologin: Add support for protocol autologin
  NFS: Remove nfs4_setup_sequence from generic rename code
  NFS: Remove nfs4_setup_sequence from generic unlink code
  NFS: Remove nfs4_setup_sequence from generic read code
  NFS: Remove nfs4_setup_sequence from generic write code
  NFS: Fix more NFS debug related build warnings
  SUNRPC/LOCKD: Fix build warnings when CONFIG_SUNRPC_DEBUG is undefined
  nfs: non void functions must return a value
  SUNRPC: Kill compiler warning when RPC_DEBUG is unset
  SUNRPC/NFS: Add Kbuild dependencies for NFS_DEBUG/RPC_DEBUG
  NFS: Use cond_resched_lock() to reduce latencies in the commit scans
  NFSv4: It is not safe to dereference lsp->ls_state in release_lockowner
  NFS: ncommit count is being double decremented
  SUNRPC: We must not use list_for_each_entry_safe() in rpc_wake_up()
  Try using machine credentials for RENEW calls
  NFSv4.1: Fix a few issues in filelayout_commit_pagelist
  NFSv4.1: Clean ups and bugfixes for the pNFS read/writeback/commit code
  ...
2012-03-23 08:53:47 -07:00
Linus Torvalds 9586c959bf Things are really quieting down with the regmap API, while we're still
seeing a trickle of new features coming in they're getting much smaller
 than they were.  It's also nice to have some features which support
 other subsystems building infrastructure on top of regmap.  Highlights
 include:
 
 - Support for padding between the register and the value when
   interacting with the device, sometimes needed for fast interfaces.
 - Support for applying register updates to the device when restoring the
   register state.  This is intended to be used to apply updates supplied by
   manufacturers for tuning the performance of the device (many of which
   are to undocumented registers which aren't otherwise covered).
 - Support for multi-register operations on cached registers.
 - Support for syncing only part of the register cache.
 - Stubs and parameter query functions intended to make it easier for other
   subsystems to build infrastructure on top of the regmap API.
 
 plus a few driver updates making use of the new features which it was
 easier to merge via this tree.
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Merge tag 'regmap-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "Things are really quieting down with the regmap API, while we're still
  seeing a trickle of new features coming in they're getting much
  smaller than they were.  It's also nice to have some features which
  support other subsystems building infrastructure on top of regmap.
  Highlights include:

  - Support for padding between the register and the value when
    interacting with the device, sometimes needed for fast interfaces.
  - Support for applying register updates to the device when restoring
    the register state.  This is intended to be used to apply updates
    supplied by manufacturers for tuning the performance of the device
    (many of which are to undocumented registers which aren't otherwise
    covered).
  - Support for multi-register operations on cached registers.
  - Support for syncing only part of the register cache.
  - Stubs and parameter query functions intended to make it easier for
    other subsystems to build infrastructure on top of the regmap API.

  plus a few driver updates making use of the new features which it was
  easier to merge via this tree."

* tag 'regmap-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap: (41 commits)
  regmap: Fix future missing prototype of devres_alloc() and friends
  regmap: Rejig struct declarations for stubbed API
  regmap: Fix rbtree block base in sync
  regcache: Make sure we sync register 0 in an rbtree cache
  regmap: delete unused module.h from drivers/base/regmap files
  regmap: Add stub for regcache_sync_region()
  mfd: Improve performance of later WM1811 revisions
  regmap: Fix x86_64 breakage
  regmap: Allow drivers to sync only part of the register cache
  regmap: Supply ranges to the sync operations
  regmap: Add tracepoints for cache only and cache bypass
  regmap: Mark the cache as clean after a successful sync
  regmap: Remove default cache sync implementation
  regmap: Skip hardware defaults for LZO caches
  regmap: Expose the driver name in debugfs
  mfd: wm8400: Convert to devm_regmap_init_i2c()
  mfd: wm831x: Convert to devm_regmap_init()
  mfd: wm8994: Convert to devm_regmap_init()
  mfd/ASoC: Convert WM8994 driver to use regmap patches
  mfd: Add __devinit and __devexit annotations in wm8994
  ...
2012-03-22 20:33:14 -07:00
Jeff Mahoney 143bede527 btrfs: return void in functions without error conditions
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
2012-03-22 01:45:34 +01:00
Linus Torvalds 69a7aebcf0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree from Jiri Kosina:
 "It's indeed trivial -- mostly documentation updates and a bunch of
  typo fixes from Masanari.

  There are also several linux/version.h include removals from Jesper."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (101 commits)
  kcore: fix spelling in read_kcore() comment
  constify struct pci_dev * in obvious cases
  Revert "char: Fix typo in viotape.c"
  init: fix wording error in mm_init comment
  usb: gadget: Kconfig: fix typo for 'different'
  Revert "power, max8998: Include linux/module.h just once in drivers/power/max8998_charger.c"
  writeback: fix fn name in writeback_inodes_sb_nr_if_idle() comment header
  writeback: fix typo in the writeback_control comment
  Documentation: Fix multiple typo in Documentation
  tpm_tis: fix tis_lock with respect to RCU
  Revert "media: Fix typo in mixer_drv.c and hdmi_drv.c"
  Doc: Update numastat.txt
  qla4xxx: Add missing spaces to error messages
  compiler.h: Fix typo
  security: struct security_operations kerneldoc fix
  Documentation: broken URL in libata.tmpl
  Documentation: broken URL in filesystems.tmpl
  mtd: simplify return logic in do_map_probe()
  mm: fix comment typo of truncate_inode_pages_range
  power: bq27x00: Fix typos in comment
  ...
2012-03-20 21:12:50 -07:00
Linus Torvalds 9c2b957db1 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events changes for v3.4 from Ingo Molnar:

 - New "hardware based branch profiling" feature both on the kernel and
   the tooling side, on CPUs that support it.  (modern x86 Intel CPUs
   with the 'LBR' hardware feature currently.)

   This new feature is basically a sophisticated 'magnifying glass' for
   branch execution - something that is pretty difficult to extract from
   regular, function histogram centric profiles.

   The simplest mode is activated via 'perf record -b', and the result
   looks like this in perf report:

	$ perf record -b any_call,u -e cycles:u branchy

	$ perf report -b --sort=symbol
	    52.34%  [.] main                   [.] f1
	    24.04%  [.] f1                     [.] f3
	    23.60%  [.] f1                     [.] f2
	     0.01%  [k] _IO_new_file_xsputn    [k] _IO_file_overflow
	     0.01%  [k] _IO_vfprintf_internal  [k] _IO_new_file_xsputn
	     0.01%  [k] _IO_vfprintf_internal  [k] strchrnul
	     0.01%  [k] __printf               [k] _IO_vfprintf_internal
	     0.01%  [k] main                   [k] __printf

   This output shows from/to branch columns and shows the highest
   percentage (from,to) jump combinations - i.e.  the most likely taken
   branches in the system.  "branches" can also include function calls
   and any other synchronous and asynchronous transitions of the
   instruction pointer that are not 'next instruction' - such as system
   calls, traps, interrupts, etc.

   This feature comes with (hopefully intuitive) flat ascii and TUI
   support in perf report.

 - Various 'perf annotate' visual improvements for us assembly junkies.
   It will now recognize function calls in the TUI and by hitting enter
   you can follow the call (recursively) and back, amongst other
   improvements.

 - Multiple threads/processes recording support in perf record, perf
   stat, perf top - which is activated via a comma-list of PIDs:

	perf top -p 21483,21485
	perf stat -p 21483,21485 -ddd
	perf record -p 21483,21485

 - Support for per UID views, via the --uid paramter to perf top, perf
   report, etc.  For example 'perf top --uid mingo' will only show the
   tasks that I am running, excluding other users, root, etc.

 - Jump label restructurings and improvements - this includes the
   factoring out of the (hopefully much clearer) include/linux/static_key.h
   generic facility:

	struct static_key key = STATIC_KEY_INIT_FALSE;

	...

	if (static_key_false(&key))
	        do unlikely code
	else
	        do likely code

	...
	static_key_slow_inc();
	...
	static_key_slow_inc();
	...

   The static_key_false() branch will be generated into the code with as
   little impact to the likely code path as possible.  the
   static_key_slow_*() APIs flip the branch via live kernel code patching.

   This facility can now be used more widely within the kernel to
   micro-optimize hot branches whose likelihood matches the static-key
   usage and fast/slow cost patterns.

 - SW function tracer improvements: perf support and filtering support.

 - Various hardenings of the perf.data ABI, to make older perf.data's
   smoother on newer tool versions, to make new features integrate more
   smoothly, to support cross-endian recording/analyzing workflows
   better, etc.

 - Restructuring of the kprobes code, the splitting out of 'optprobes',
   and a corner case bugfix.

 - Allow the tracing of kernel console output (printk).

 - Improvements/fixes to user-space RDPMC support, allowing user-space
   self-profiling code to extract PMU counts without performing any
   system calls, while playing nice with the kernel side.

 - 'perf bench' improvements

 - ... and lots of internal restructurings, cleanups and fixes that made
   these features possible.  And, as usual this list is incomplete as
   there were also lots of other improvements

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (120 commits)
  perf report: Fix annotate double quit issue in branch view mode
  perf report: Remove duplicate annotate choice in branch view mode
  perf/x86: Prettify pmu config literals
  perf report: Enable TUI in branch view mode
  perf report: Auto-detect branch stack sampling mode
  perf record: Add HEADER_BRANCH_STACK tag
  perf record: Provide default branch stack sampling mode option
  perf tools: Make perf able to read files from older ABIs
  perf tools: Fix ABI compatibility bug in print_event_desc()
  perf tools: Enable reading of perf.data files from different ABI rev
  perf: Add ABI reference sizes
  perf report: Add support for taken branch sampling
  perf record: Add support for sampling taken branch
  perf tools: Add code to support PERF_SAMPLE_BRANCH_STACK
  x86/kprobes: Split out optprobe related code to kprobes-opt.c
  x86/kprobes: Fix a bug which can modify kernel code permanently
  x86/kprobes: Fix instruction recovery on optimized path
  perf: Add callback to flush branch_stack on context switch
  perf: Disable PERF_SAMPLE_BRANCH_* when not supported
  perf/x86: Add LBR software filter support for Intel CPUs
  ...
2012-03-20 10:29:15 -07:00
Paul Gortmaker 313162d0b8 device.h: audit and cleanup users in main include dir
The <linux/device.h> header includes a lot of stuff, and
it in turn gets a lot of use just for the basic "struct device"
which appears so often.

Clean up the users as follows:

1) For those headers only needing "struct device" as a pointer
in fcn args, replace the include with exactly that.

2) For headers not really using anything from device.h, simply
delete the include altogether.

3) For headers relying on getting device.h implicitly before
being included themselves, now explicitly include device.h

4) For files in which doing #1 or #2 uncovers an implicit
dependency on some other header, fix by explicitly adding
the required header(s).

Any C files that were implicitly relying on device.h to be
present have already been dealt with in advance.

Total removals from #1 and #2: 51.  Total additions coming
from #3: 9.  Total other implicit dependencies from #4: 7.

As of 3.3-rc1, there were 110, so a net removal of 42 gives
about a 38% reduction in device.h presence in include/*

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-03-16 10:38:24 -04:00
Mark Brown 7d9aca39dc Merge remote-tracking branch 'regmap/topic/drivers' into regmap-next
Resolved simple add/add conflicts:
	drivers/base/regmap/internal.h
	drivers/base/regmap/regmap.c
2012-03-14 13:13:25 +00:00
Jan Kara 79feb521a4 jbd2: issue cache flush after checkpointing even with internal journal
When we reach jbd2_cleanup_journal_tail(), there is no guarantee that
checkpointed buffers are on a stable storage - especially if buffers were
written out by jbd2_log_do_checkpoint(), they are likely to be only in disk's
caches. Thus when we update journal superblock effectively removing old
transaction from journal, this write of superblock can get to stable storage
before those checkpointed buffers which can result in filesystem corruption
after a crash. Thus we must unconditionally issue a cache flush before we
update journal superblock in these cases.

A similar problem can also occur if journal superblock is written only in
disk's caches, other transaction starts reusing space of the transaction
cleaned from the log and power failure happens. Subsequent journal replay would
still try to replay the old transaction but some of it's blocks may be already
overwritten by the new transaction. For this reason we must use WRITE_FUA when
updating log tail and we must first write new log tail to disk and update
in-memory information only after that.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-03-13 22:22:54 -04:00
Jan Kara 24bcc89c7e jbd2: split updating of journal superblock and marking journal empty
There are three case of updating journal superblock. In the first case, we want
to mark journal as empty (setting s_sequence to 0), in the second case we want
to update log tail, in the third case we want to update s_errno. Split these
cases into separate functions. It makes the code slightly more straightforward
and later patches will make the distinction even more important.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-03-13 15:41:04 -04:00
Ingo Molnar 737f24bda7 Merge branch 'perf/urgent' into perf/core
Conflicts:
	tools/perf/builtin-record.c
	tools/perf/builtin-top.c
	tools/perf/perf.h
	tools/perf/util/top.h

Merge reason: resolve these cherry-picking conflicts.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-05 09:20:08 +01:00
Ingo Molnar bdd4431c8d Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
The major features of this series are:

 - making RCU more aggressive about entering dyntick-idle mode in order to
   improve energy efficiency

 - converting a few more call_rcu()s to kfree_rcu()s

 - applying a number of rcutree fixes and cleanups to rcutiny

 - removing CONFIG_SMP #ifdefs from treercu

 - allowing RCU CPU stall times to be set via sysfs

 - adding CPU-stall capability to rcutorture

 - adding more RCU-abuse diagnostics

 - updating documentation

 - fixing yet more issues located by the still-ongoing top-to-bottom
   inspection of RCU, this time with a special focus on the
   CPU-hotplug code path.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-28 10:16:10 +01:00
Mark Brown 5d5b7d4f80 regmap: Add tracepoints for cache only and cache bypass
Useful for figuring out where the hardware interaction went or came from.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2012-02-23 22:10:56 +00:00
David Smith 4ff16c25e2 tracepoint, vfs, sched: Add exec() tracepoint
Added a minimal exec tracepoint. Exec is an important major event
in the life of a task, like fork(), clone() or exit(), all of
which we already trace.

[ We also do scheduling re-balancing during exec() - so it's useful
  from a scheduler instrumentation POV as well. ]

If you want to watch a task start up, when it gets exec'ed is a good place
to start.  With the addition of this tracepoint, exec's can be monitored
and better picture of general system activity can be obtained. This
tracepoint will also enable better process life tracking, allowing you to
answer questions like "what process keeps starting up binary X?".

This tracepoint can also be useful in ftrace filtering and trigger
conditions: i.e. starting or stopping filtering when exec is called.

Signed-off-by: David Smith <dsmith@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/4F314D19.7030504@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-23 09:28:06 +01:00
Peter Zijlstra 8c79a045fd sched/events: Revert trace_sched_stat_sleeptime()
Commit 1ac9bc69 ("sched/tracing: Add a new tracepoint for sleeptime")
added a new sched:sched_stat_sleeptime tracepoint.

It's broken: the first sample we get on a task might be bad because
of a stale sleep_start value that wasn't reset at the last task switch
because the tracepoint was not active.

It also breaks the existing schedstat samples due to the side
effects of:

-               se->statistics.sleep_start = 0;
...
-               se->statistics.block_start = 0;

Nor do I see means to fix it without adding overhead to the scheduler
fast path, which I'm not willing to for the sake of redundant
instrumentation.

Most importantly, sleep time information can already be constructed
by tracing context switches and wakeups, and taking the timestamp
difference between the schedule-out, the wakeup and the schedule-in.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Vagin <avagin@openvz.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-pc4c9qhl8q6vg3bs4j6k0rbd@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-22 12:06:55 +01:00
Paul E. McKenney 486e259340 rcu: Avoid waking up CPUs having only kfree_rcu() callbacks
When CONFIG_RCU_FAST_NO_HZ is enabled, RCU will allow a given CPU to
enter dyntick-idle mode even if it still has RCU callbacks queued.
RCU avoids system hangs in this case by scheduling a timer for several
jiffies in the future.  However, if all of the callbacks on that CPU
are from kfree_rcu(), there is no reason to wake the CPU up, as it is
not a problem to defer freeing of memory.

This commit therefore tracks the number of callbacks on a given CPU
that are from kfree_rcu(), and avoids scheduling the timer if all of
a given CPU's callbacks are from kfree_rcu().

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-02-21 09:03:25 -08:00
Seiji Aguchi 2201c590dd jbd2: add drop_transaction/update_superblock_end tracepoints
This patch adds trace_jbd2_drop_transaction and
trace_jbd2_update_superblock_end because there are similar tracepoints
in jbd and they are needed in jbd2 as well.

Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-02-20 17:53:01 -05:00
Johannes Berg 9510035849 printk/tracing: Add console output tracing
Add a printk.console trace point to record any printk
messages into the trace, regardless of the current
console loglevel. This can help correlate (existing)
printk debugging with other tracing.

Link: http://lkml.kernel.org/r/1322161388.5366.54.camel@jlt3.sipsolutions.net

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-02-13 13:46:05 -05:00
Steven Rostedt 484546509c x86/tracing: Denote the power and cpuidle tracepoints as _rcuidle()
The power and cpuidle tracepoints are called within a rcu_idle_exit()
section, and must be denoted with the _rcuidle() version of the tracepoint.

Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-02-13 09:14:43 -05:00
Steve Dickson 5753cba176 SUNRPC: Adding status trace points
This patch adds three trace points to the status routines
in the sunrpc state machine.

The goal of these trace points is to give an Admin
the ability to check on binding status or connection
status to see if there is a potential problem.

Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-02-06 10:37:53 -05:00
Trond Myklebust 85c0d24f02 SUNRPC: Fix up sunrpc trace events
The reporting of the RPC queue name needs to use the __string()
event interface.

Reported-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-02-06 10:31:35 -05:00
Wu Fengguang 977b7e3a52 writeback: fix dereferencing NULL bdi->dev on trace_writeback_queue
When a SD card is hot removed without umount, del_gendisk() will call
bdi_unregister() without destroying/freeing it. This leaves the bdi in
the bdi->dev = NULL, bdi->wb.task = NULL, bdi->bdi_list removed state.

When sync(2) gets the bdi before bdi_unregister() and calls
bdi_queue_work() after the unregister, trace_writeback_queue will be
dereferencing the NULL bdi->dev. Fix it with a simple test for NULL.

LKML-reference: http://lkml.org/lkml/2012/1/18/346
Cc: stable@kernel.org
Reported-by: Rabin Vincent <rabin@rab.in>
Tested-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2012-02-06 11:17:25 +08:00
Jesper Juhl 42481ba290 Remove incorrect comment from include/trace/events/power.h
The code is not going to be removed, so remove the comment stating
that it will be.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-02-05 15:53:02 +01:00