09 Nov, 2010
1 commit
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Add ext4_evict_inode, ext4_drop_inode, ext4_mark_inode_dirty, and
ext4_begin_ordered_truncate()Signed-off-by: "Theodore Ts'o"
28 Oct, 2010
6 commits
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Conflicts:
fs/ext4/inode.c
fs/ext4/mballoc.c
include/trace/events/ext4.h -
Unfortunately perf can't deal with anything other than direct structure
accesses in the TP_printk() section. It will drop dead when it sees
jbd2_dev_to_name() in the "print fmt" section of the tracepoint.Addresses-Google-Bug: 3138508
Signed-off-by: "Theodore Ts'o"
-
…/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (50 commits)
perf python scripting: Add futex-contention script
perf python scripting: Fixup cut'n'paste error in sctop script
perf scripting: Shut up 'perf record' final status
perf record: Remove newline character from perror() argument
perf python scripting: Support fedora 11 (audit 1.7.17)
perf python scripting: Improve the syscalls-by-pid script
perf python scripting: print the syscall name on sctop
perf python scripting: Improve the syscalls-counts script
perf python scripting: Improve the failed-syscalls-by-pid script
kprobes: Remove redundant text_mutex lock in optimize
x86/oprofile: Fix uninitialized variable use in debug printk
tracing: Fix 'faild' -> 'failed' typo
perf probe: Fix format specified for Dwarf_Off parameter
perf trace: Fix detection of script extension
perf trace: Use $PERF_EXEC_PATH in canned report scripts
perf tools: Document event modifiers
perf tools: Remove direct slang.h include
perf_events: Fix for transaction recovery in group_sched_in()
perf_events: Revert: Fix transaction recovery in group_sched_in()
perf, x86: Use NUMA aware allocations for PEBS/BTS/DS allocations
... -
Many tracepoints were populating an ext4_allocation_context
to pass in, but this requires a slab allocation even when
tracepoints are off. In fact, 4 of 5 of these allocations
were only for tracing. In addition, we were only using a
small fraction of the 144 bytes of this structure for this
purpose.We can do away with all these alloc/frees of the ac and
simply pass in the bits we care about, instead.I tested this by turning on tracing and running through
xfstests on x86_64. I did not actually do anything with
the trace output, however.Signed-off-by: Eric Sandeen
Signed-off-by: "Theodore Ts'o" -
Our QA reported an oops in the ext4_mb_release_group_pa tracing,
and Josef Bacik pointed out that it was because we may have a
non-null but uninitialized ac_inode in the allocation context.I can reproduce it when running xfstests with ext4 tracepoints on,
on a CONFIG_SLAB_DEBUG kernel.We call trace_ext4_mb_release_group_pa from 2 places,
ext4_mb_discard_group_preallocations and
ext4_mb_discard_lg_preallocationsIn both cases we allocate an ac as a container just for tracing (!)
and never fill in the ac_inode. There's no reason to be assigning,
testing, or printing it as far as I can see, so just remove it from
the tracepoint.Signed-off-by: Eric Sandeen
Reviewed-by: Josef Bacik
Signed-off-by: "Theodore Ts'o" -
ac->inode is set to null in function ext4_mb_release_group_pa(),
and then trace_ext4_mballoc_discard(ac) is called, the kernel
will panic.BUG: unable to handle kernel NULL pointer dereference at 000000a4
IP: [] ftrace_raw_event_ext4__mballoc+0x54/0xc0 [ext4]
*pdpt = 0000000000abd001 *pde = 0000000000000000
Oops: 0000 [#1] SMPPid: 550, comm: flush-8:16 Not tainted 2.6.36-rc1 #1 SE7320EP2/Altos G530
EIP: 0060:[] EFLAGS: 00010206 CPU: 1
EIP is at ftrace_raw_event_ext4__mballoc+0x54/0xc0 [ext4]
EAX: f32ac840 EBX: f3f1cf88 ECX: f32ac840 EDX: 00000000
ESI: f32ac83c EDI: f880b9d8 EBP: 00000000 ESP: f4b77ae4
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process flush-8:16 (pid: 550, ti=f4b76000 task=f613e540 task.ti=f4b76000)
Call Trace:
[] ? ext4_mb_release_group_pa+0x121/0x150 [ext4]
[] ? ext4_mb_discard_group_preallocations+0x336/0x400 [ext4]
[] ? ext4_mb_new_blocks+0x3d1/0x4f0 [ext4]
[] ? __make_request+0x10b/0x440
[] ? ext4_ext_map_blocks+0x1334/0x1980 [ext4]
[] ? rb_reserve_next_event+0xaa/0x3b0
[] ? ext4_map_blocks+0xd6/0x1d0 [ext4]
[] ? mpage_da_map_blocks+0xc7/0x8a0 [ext4]
[] ? find_get_pages_tag+0x38/0x110
[] ? __pagevec_release+0x15/0x20
[] ? ext4_da_writepages+0x2b5/0x5d0 [ext4]
[] ? __writepage+0x0/0x30
[] ? do_writepages+0x14/0x30
[] ? writeback_single_inode+0xa0/0x240
[] ? writeback_sb_inodes+0xc1/0x180
[] ? writeback_inodes_wb+0x88/0x140
[] ? wb_writeback+0x20b/0x320
[] ? lock_timer_base+0x27/0x50
[] ? wb_do_writeback+0x150/0x190
[] ? bdi_writeback_thread+0x88/0x1f0
[] ? complete+0x40/0x60
[] ? bdi_writeback_thread+0x0/0x1f0
[] ? kthread+0x74/0x80
[] ? kthread+0x0/0x80
[] ? kernel_thread_helper+0x6/0x10Signed-off-by: Wen Congyang
Acked-by: Steven Rostedt
Signed-off-by: "Theodore Ts'o"
27 Oct, 2010
5 commits
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…r if significant congestion is not being encountered in the current zone
If congestion_wait() is called with no BDI congested, the caller will
sleep for the full timeout and this may be an unnecessary sleep. This
patch adds a wait_iff_congested() that checks congestion and only sleeps
if a BDI is congested else, it calls cond_resched() to ensure the caller
is not hogging the CPU longer than its quota but otherwise will not sleep.This is aimed at reducing some of the major desktop stalls reported during
IO. For example, while kswapd is operating, it calls congestion_wait()
but it could just have been reclaiming clean page cache pages with no
congestion. Without this patch, it would sleep for a full timeout but
after this patch, it'll just call schedule() if it has been on the CPU too
long. Similar logic applies to direct reclaimers that are not making
enough progress.Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> -
shrink_page_list() can decide to give up reclaiming a page under a
number of conditions such as1. trylock_page() failure
2. page is unevictable
3. zone reclaim and page is mapped
4. PageWriteback() is true
5. page is swapbacked and swap is full
6. add_to_swap() failure
7. page is dirty and gfpmask don't have GFP_IO, GFP_FS
8. page is pinned
9. IO queue is congested
10. pageout() start IO, but not finishedWith lumpy reclaim, failures result in entering synchronous lumpy reclaim
but this can be unnecessary. In cases (2), (3), (5), (6), (7) and (8),
there is no point retrying. This patch causes lumpy reclaim to abort when
it is known it will fail.Case (9) is more interesting. current behavior is,
1. start shrink_page_list(async)
2. found queue_congested()
3. skip pageout write
4. still start shrink_page_list(sync)
5. wait on a lot of pages
6. again, found queue_congested()
7. give up pageout write againSo, it's useless time wasting. However, just skipping page reclaim is
also notgood as x86 allocating a huge page needs 512 pages for example.
It can have more dirty pages than queue congestion threshold (~=128).After this patch, pageout() behaves as follows;
- If order > PAGE_ALLOC_COSTLY_ORDER
Ignore queue congestion always.
- If order
Signed-off-by: Mel Gorman
Reviewed-by: KAMEZAWA Hiroyuki
Cc: Johannes Weiner
Cc: Minchan Kim
Cc: Wu Fengguang
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
There is strong evidence to indicate a lot of time is being spent in
congestion_wait(), some of it unnecessarily. This patch adds a tracepoint
for congestion_wait to record when congestion_wait() was called, how long
the timeout was for and how long it actually slept.Signed-off-by: Mel Gorman
Reviewed-by: Minchan Kim
Reviewed-by: Johannes Weiner
Cc: Wu Fengguang
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
There have been numerous reports of stalls that pointed at the problem
being somewhere in the VM. There are multiple roots to the problems which
means dealing with any of the root problems in isolation is tricky to
justify on their own and they would still need integration testing. This
patch series puts together two different patch sets which in combination
should tackle some of the root causes of latency problems being reported.Patch 1 adds a tracepoint for shrink_inactive_list. For this series, the
most important results is being able to calculate the scanning/reclaim
ratio as a measure of the amount of work being done by page reclaim.Patch 2 accounts for time spent in congestion_wait.
Patches 3-6 were originally developed by Kosaki Motohiro but reworked for
this series. It has been noted that lumpy reclaim is far too aggressive
and trashes the system somewhat. As SLUB uses high-order allocations, a
large cost incurred by lumpy reclaim will be noticeable. It was also
reported during transparent hugepage support testing that lumpy reclaim
was trashing the system and these patches should mitigate that problem
without disabling lumpy reclaim.Patch 7 adds wait_iff_congested() and replaces some callers of
congestion_wait(). wait_iff_congested() only sleeps if there is a BDI
that is currently congested. Patch 8 notes that any BDI being congested
is not necessarily a problem because there could be multiple BDIs of
varying speeds and numberous zones. It attempts to track when a zone
being reclaimed contains many pages backed by a congested BDI and if so,
reclaimers wait on the congestion queue.I ran a number of tests with monitoring on X86, X86-64 and PPC64. Each
machine had 3G of RAM and the CPUs wereX86: Intel P4 2-core
X86-64: AMD Phenom 4-core
PPC64: PPC970MPEach used a single disk and the onboard IO controller. Dirty ratio was
left at 20. I'm just going to report for X86-64 and PPC64 in a vague
attempt to keep this report short. Four kernels were tested each based on
v2.6.36-rc4traceonly-v2r2: Patches 1 and 2 to instrument vmscan reclaims and congestion_wait
lowlumpy-v2r3: Patches 1-6 to test if lumpy reclaim is better
waitcongest-v2r3: Patches 1-7 to only wait on congestion
waitwriteback-v2r4: Patches 1-8 to detect when a zone is congestednocongest-v1r5: Patches 1-3 for testing wait_iff_congestion
nodirect-v1r5: Patches 1-10 to disable filesystem writeback for better IOThe tests run were as follows
kernbench
compile-based benchmark. Smoke test performancesysbench
OLTP read-only benchmark. Will be re-run in the future as read-writemicro-mapped-file-stream
This is a micro-benchmark from Johannes Weiner that accesses a
large sparse-file through mmap(). It was configured to run in only
single-CPU mode but can be indicative of how well page reclaim
identifies suitable pages.stress-highalloc
Tries to allocate huge pages under heavy load.kernbench, iozone and sysbench did not report any performance regression
on any machine. sysbench did pressure the system lightly and there was
reclaim activity but there were no difference of major interest between
the kernels.X86-64 micro-mapped-file-stream
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3 waitwriteback-v2r4
pgalloc_dma 1639.00 ( 0.00%) 667.00 (-145.73%) 1167.00 ( -40.45%) 578.00 (-183.56%)
pgalloc_dma32 2842410.00 ( 0.00%) 2842626.00 ( 0.01%) 2843043.00 ( 0.02%) 2843014.00 ( 0.02%)
pgalloc_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgsteal_dma 729.00 ( 0.00%) 85.00 (-757.65%) 609.00 ( -19.70%) 125.00 (-483.20%)
pgsteal_dma32 2338721.00 ( 0.00%) 2447354.00 ( 4.44%) 2429536.00 ( 3.74%) 2436772.00 ( 4.02%)
pgsteal_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgscan_kswapd_dma 1469.00 ( 0.00%) 532.00 (-176.13%) 1078.00 ( -36.27%) 220.00 (-567.73%)
pgscan_kswapd_dma32 4597713.00 ( 0.00%) 4503597.00 ( -2.09%) 4295673.00 ( -7.03%) 3891686.00 ( -18.14%)
pgscan_kswapd_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgscan_direct_dma 71.00 ( 0.00%) 134.00 ( 47.01%) 243.00 ( 70.78%) 352.00 ( 79.83%)
pgscan_direct_dma32 305820.00 ( 0.00%) 280204.00 ( -9.14%) 600518.00 ( 49.07%) 957485.00 ( 68.06%)
pgscan_direct_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pageoutrun 16296.00 ( 0.00%) 21254.00 ( 23.33%) 18447.00 ( 11.66%) 20067.00 ( 18.79%)
allocstall 443.00 ( 0.00%) 273.00 ( -62.27%) 513.00 ( 13.65%) 1568.00 ( 71.75%)These are based on the raw figures taken from /proc/vmstat. It's a rough
measure of reclaim activity. Note that allocstall counts are higher
because we are entering direct reclaim more often as a result of not
sleeping in congestion. In itself, it's not necessarily a bad thing.
It's easier to get a view of what happened from the vmscan tracepoint
report.FTrace Reclaim Statistics: vmscan
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3 waitwriteback-v2r4
Direct reclaims 443 273 513 1568
Direct reclaim pages scanned 305968 280402 600825 957933
Direct reclaim pages reclaimed 43503 19005 30327 117191
Direct reclaim write file async I/O 0 0 0 0
Direct reclaim write anon async I/O 0 3 4 12
Direct reclaim write file sync I/O 0 0 0 0
Direct reclaim write anon sync I/O 0 0 0 0
Wake kswapd requests 187649 132338 191695 267701
Kswapd wakeups 3 1 4 1
Kswapd pages scanned 4599269 4454162 4296815 3891906
Kswapd pages reclaimed 2295947 2428434 2399818 2319706
Kswapd reclaim write file async I/O 1 0 1 1
Kswapd reclaim write anon async I/O 59 187 41 222
Kswapd reclaim write file sync I/O 0 0 0 0
Kswapd reclaim write anon sync I/O 0 0 0 0
Time stalled direct reclaim (seconds) 4.34 2.52 6.63 2.96
Time kswapd awake (seconds) 11.15 10.25 11.01 10.19Total pages scanned 4905237 4734564 4897640 4849839
Total pages reclaimed 2339450 2447439 2430145 2436897
%age total pages scanned/reclaimed 47.69% 51.69% 49.62% 50.25%
%age total pages scanned/written 0.00% 0.00% 0.00% 0.00%
%age file pages scanned/written 0.00% 0.00% 0.00% 0.00%
Percentage Time Spent Direct Reclaim 29.23% 19.02% 38.48% 20.25%
Percentage Time kswapd Awake 78.58% 78.85% 76.83% 79.86%What is interesting here for nocongest in particular is that while direct
reclaim scans more pages, the overall number of pages scanned remains the
same and the ratio of pages scanned to pages reclaimed is more or less the
same. In other words, while we are sleeping less, reclaim is not doing
more work and as direct reclaim and kswapd is awake for less time, it
would appear to be doing less work.FTrace Reclaim Statistics: congestion_wait
Direct number congest waited 87 196 64 0
Direct time congest waited 4604ms 4732ms 5420ms 0ms
Direct full congest waited 72 145 53 0
Direct number conditional waited 0 0 324 1315
Direct time conditional waited 0ms 0ms 0ms 0ms
Direct full conditional waited 0 0 0 0
KSwapd number congest waited 20 10 15 7
KSwapd time congest waited 1264ms 536ms 884ms 284ms
KSwapd full congest waited 10 4 6 2
KSwapd number conditional waited 0 0 0 0
KSwapd time conditional waited 0ms 0ms 0ms 0ms
KSwapd full conditional waited 0 0 0 0The vanilla kernel spent 8 seconds asleep in direct reclaim and no time at
all asleep with the patches.MMTests Statistics: duration
User/Sys Time Running Test (seconds) 10.51 10.73 10.6 11.66
Total Elapsed Time (seconds) 14.19 13.00 14.33 12.76Overall, the tests completed faster. It is interesting to note that backing off further
when a zone is congested and not just a BDI was more efficient overall.PPC64 micro-mapped-file-stream
pgalloc_dma 3024660.00 ( 0.00%) 3027185.00 ( 0.08%) 3025845.00 ( 0.04%) 3026281.00 ( 0.05%)
pgalloc_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgsteal_dma 2508073.00 ( 0.00%) 2565351.00 ( 2.23%) 2463577.00 ( -1.81%) 2532263.00 ( 0.96%)
pgsteal_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgscan_kswapd_dma 4601307.00 ( 0.00%) 4128076.00 ( -11.46%) 3912317.00 ( -17.61%) 3377165.00 ( -36.25%)
pgscan_kswapd_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pgscan_direct_dma 629825.00 ( 0.00%) 971622.00 ( 35.18%) 1063938.00 ( 40.80%) 1711935.00 ( 63.21%)
pgscan_direct_normal 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%) 0.00 ( 0.00%)
pageoutrun 27776.00 ( 0.00%) 20458.00 ( -35.77%) 18763.00 ( -48.04%) 18157.00 ( -52.98%)
allocstall 977.00 ( 0.00%) 2751.00 ( 64.49%) 2098.00 ( 53.43%) 5136.00 ( 80.98%)Similar trends to x86-64. allocstalls are up but it's not necessarily bad.
FTrace Reclaim Statistics: vmscan
Direct reclaims 977 2709 2098 5136
Direct reclaim pages scanned 629825 963814 1063938 1711935
Direct reclaim pages reclaimed 75550 242538 150904 387647
Direct reclaim write file async I/O 0 0 0 2
Direct reclaim write anon async I/O 0 10 0 4
Direct reclaim write file sync I/O 0 0 0 0
Direct reclaim write anon sync I/O 0 0 0 0
Wake kswapd requests 392119 1201712 571935 571921
Kswapd wakeups 3 2 3 3
Kswapd pages scanned 4601307 4128076 3912317 3377165
Kswapd pages reclaimed 2432523 2318797 2312673 2144616
Kswapd reclaim write file async I/O 20 1 1 1
Kswapd reclaim write anon async I/O 57 132 11 121
Kswapd reclaim write file sync I/O 0 0 0 0
Kswapd reclaim write anon sync I/O 0 0 0 0
Time stalled direct reclaim (seconds) 6.19 7.30 13.04 10.88
Time kswapd awake (seconds) 21.73 26.51 25.55 23.90Total pages scanned 5231132 5091890 4976255 5089100
Total pages reclaimed 2508073 2561335 2463577 2532263
%age total pages scanned/reclaimed 47.95% 50.30% 49.51% 49.76%
%age total pages scanned/written 0.00% 0.00% 0.00% 0.00%
%age file pages scanned/written 0.00% 0.00% 0.00% 0.00%
Percentage Time Spent Direct Reclaim 18.89% 20.65% 32.65% 27.65%
Percentage Time kswapd Awake 72.39% 80.68% 78.21% 77.40%Again, a similar trend that the congestion_wait changes mean that direct
reclaim scans more pages but the overall number of pages scanned while
slightly reduced, are very similar. The ratio of scanning/reclaimed
remains roughly similar. The downside is that kswapd and direct reclaim
was awake longer and for a larger percentage of the overall workload.
It's possible there were big differences in the amount of time spent
reclaiming slab pages between the different kernels which is plausible
considering that the micro tests runs after fsmark and sysbench.Trace Reclaim Statistics: congestion_wait
Direct number congest waited 845 1312 104 0
Direct time congest waited 19416ms 26560ms 7544ms 0ms
Direct full congest waited 745 1105 72 0
Direct number conditional waited 0 0 1322 2935
Direct time conditional waited 0ms 0ms 12ms 312ms
Direct full conditional waited 0 0 0 3
KSwapd number congest waited 39 102 75 63
KSwapd time congest waited 2484ms 6760ms 5756ms 3716ms
KSwapd full congest waited 20 48 46 25
KSwapd number conditional waited 0 0 0 0
KSwapd time conditional waited 0ms 0ms 0ms 0ms
KSwapd full conditional waited 0 0 0 0The vanilla kernel spent 20 seconds asleep in direct reclaim and only
312ms asleep with the patches. The time kswapd spent congest waited was
also reduced by a large factor.MMTests Statistics: duration
ser/Sys Time Running Test (seconds) 26.58 28.05 26.9 28.47
Total Elapsed Time (seconds) 30.02 32.86 32.67 30.88With all patches applies, the completion times are very similar.
X86-64 STRESS-HIGHALLOC
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3waitwriteback-v2r4
Pass 1 82.00 ( 0.00%) 84.00 ( 2.00%) 85.00 ( 3.00%) 85.00 ( 3.00%)
Pass 2 90.00 ( 0.00%) 87.00 (-3.00%) 88.00 (-2.00%) 89.00 (-1.00%)
At Rest 92.00 ( 0.00%) 90.00 (-2.00%) 90.00 (-2.00%) 91.00 (-1.00%)Success figures across the board are broadly similar.
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3waitwriteback-v2r4
Direct reclaims 1045 944 886 887
Direct reclaim pages scanned 135091 119604 109382 101019
Direct reclaim pages reclaimed 88599 47535 47863 46671
Direct reclaim write file async I/O 494 283 465 280
Direct reclaim write anon async I/O 29357 13710 16656 13462
Direct reclaim write file sync I/O 154 2 2 3
Direct reclaim write anon sync I/O 14594 571 509 561
Wake kswapd requests 7491 933 872 892
Kswapd wakeups 814 778 731 780
Kswapd pages scanned 7290822 15341158 11916436 13703442
Kswapd pages reclaimed 3587336 3142496 3094392 3187151
Kswapd reclaim write file async I/O 91975 32317 28022 29628
Kswapd reclaim write anon async I/O 1992022 789307 829745 849769
Kswapd reclaim write file sync I/O 0 0 0 0
Kswapd reclaim write anon sync I/O 0 0 0 0
Time stalled direct reclaim (seconds) 4588.93 2467.16 2495.41 2547.07
Time kswapd awake (seconds) 2497.66 1020.16 1098.06 1176.82Total pages scanned 7425913 15460762 12025818 13804461
Total pages reclaimed 3675935 3190031 3142255 3233822
%age total pages scanned/reclaimed 49.50% 20.63% 26.13% 23.43%
%age total pages scanned/written 28.66% 5.41% 7.28% 6.47%
%age file pages scanned/written 1.25% 0.21% 0.24% 0.22%
Percentage Time Spent Direct Reclaim 57.33% 42.15% 42.41% 42.99%
Percentage Time kswapd Awake 43.56% 27.87% 29.76% 31.25%Scanned/reclaimed ratios again look good with big improvements in
efficiency. The Scanned/written ratios also look much improved. With a
better scanned/written ration, there is an expectation that IO would be
more efficient and indeed, the time spent in direct reclaim is much
reduced by the full series and kswapd spends a little less time awake.Overall, indications here are that allocations were happening much faster
and this can be seen with a graph of the latency figures as the
allocations were taking place
http://www.csn.ul.ie/~mel/postings/vmscanreduce-20101509/highalloc-interlatency-hydra-mean.psFTrace Reclaim Statistics: congestion_wait
Direct number congest waited 1333 204 169 4
Direct time congest waited 78896ms 8288ms 7260ms 200ms
Direct full congest waited 756 92 69 2
Direct number conditional waited 0 0 26 186
Direct time conditional waited 0ms 0ms 0ms 2504ms
Direct full conditional waited 0 0 0 25
KSwapd number congest waited 4 395 227 282
KSwapd time congest waited 384ms 25136ms 10508ms 18380ms
KSwapd full congest waited 3 232 98 176
KSwapd number conditional waited 0 0 0 0
KSwapd time conditional waited 0ms 0ms 0ms 0ms
KSwapd full conditional waited 0 0 0 0
KSwapd full conditional waited 318 0 312 9Overall, the time spent speeping is reduced. kswapd is still hitting
congestion_wait() but that is because there are callers remaining where it
wasn't clear in advance if they should be changed to wait_iff_congested()
or not. Overall the sleep imes are reduced though - from 79ish seconds to
about 19.MMTests Statistics: duration
User/Sys Time Running Test (seconds) 3415.43 3386.65 3388.39 3377.5
Total Elapsed Time (seconds) 5733.48 3660.33 3689.41 3765.39With the full series, the time to complete the tests are reduced by 30%
PPC64 STRESS-HIGHALLOC
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3waitwriteback-v2r4
Pass 1 17.00 ( 0.00%) 34.00 (17.00%) 38.00 (21.00%) 43.00 (26.00%)
Pass 2 25.00 ( 0.00%) 37.00 (12.00%) 42.00 (17.00%) 46.00 (21.00%)
At Rest 49.00 ( 0.00%) 43.00 (-6.00%) 45.00 (-4.00%) 51.00 ( 2.00%)Success rates there are *way* up particularly considering that the 16MB
huge pages on PPC64 mean that it's always much harder to allocate them.FTrace Reclaim Statistics: vmscan
stress-highalloc stress-highalloc stress-highalloc stress-highalloc
traceonly-v2r2 lowlumpy-v2r3 waitcongest-v2r3waitwriteback-v2r4
Direct reclaims 499 505 564 509
Direct reclaim pages scanned 223478 41898 51818 45605
Direct reclaim pages reclaimed 137730 21148 27161 23455
Direct reclaim write file async I/O 399 136 162 136
Direct reclaim write anon async I/O 46977 2865 4686 3998
Direct reclaim write file sync I/O 29 0 1 3
Direct reclaim write anon sync I/O 31023 159 237 239
Wake kswapd requests 420 351 360 326
Kswapd wakeups 185 294 249 277
Kswapd pages scanned 15703488 16392500 17821724 17598737
Kswapd pages reclaimed 5808466 2908858 3139386 3145435
Kswapd reclaim write file async I/O 159938 18400 18717 13473
Kswapd reclaim write anon async I/O 3467554 228957 322799 234278
Kswapd reclaim write file sync I/O 0 0 0 0
Kswapd reclaim write anon sync I/O 0 0 0 0
Time stalled direct reclaim (seconds) 9665.35 1707.81 2374.32 1871.23
Time kswapd awake (seconds) 9401.21 1367.86 1951.75 1328.88Total pages scanned 15926966 16434398 17873542 17644342
Total pages reclaimed 5946196 2930006 3166547 3168890
%age total pages scanned/reclaimed 37.33% 17.83% 17.72% 17.96%
%age total pages scanned/written 23.27% 1.52% 1.94% 1.43%
%age file pages scanned/written 1.01% 0.11% 0.11% 0.08%
Percentage Time Spent Direct Reclaim 44.55% 35.10% 41.42% 36.91%
Percentage Time kswapd Awake 86.71% 43.58% 52.67% 41.14%While the scanning rates are slightly up, the scanned/reclaimed and
scanned/written figures are much improved. The time spent in direct
reclaim and with kswapd are massively reduced, mostly by the lowlumpy
patches.FTrace Reclaim Statistics: congestion_wait
Direct number congest waited 725 303 126 3
Direct time congest waited 45524ms 9180ms 5936ms 300ms
Direct full congest waited 487 190 52 3
Direct number conditional waited 0 0 200 301
Direct time conditional waited 0ms 0ms 0ms 1904ms
Direct full conditional waited 0 0 0 19
KSwapd number congest waited 0 2 23 4
KSwapd time congest waited 0ms 200ms 420ms 404ms
KSwapd full congest waited 0 2 2 4
KSwapd number conditional waited 0 0 0 0
KSwapd time conditional waited 0ms 0ms 0ms 0ms
KSwapd full conditional waited 0 0 0 0Not as dramatic a story here but the time spent asleep is reduced and we
can still see what wait_iff_congested is going to sleep when necessary.MMTests Statistics: duration
User/Sys Time Running Test (seconds) 12028.09 3157.17 3357.79 3199.16
Total Elapsed Time (seconds) 10842.07 3138.72 3705.54 3229.85The time to complete this test goes way down. With the full series, we
are allocating over twice the number of huge pages in 30% of the time and
there is a corresponding impact on the allocation latency graph available
at.http://www.csn.ul.ie/~mel/postings/vmscanreduce-20101509/highalloc-interlatency-powyah-mean.ps
This patch:
Add a trace event for shrink_inactive_list() and updates the sample
postprocessing script appropriately. It can be used to determine how many
pages were reclaimed and for non-lumpy reclaim where exactly the pages
were reclaimed from.Signed-off-by: Mel Gorman
Cc: Johannes Weiner
Cc: Minchan Kim
Cc: Wu Fengguang
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This removes more dead code that was somehow missed by commit 0d99519efef
(writeback: remove unused nonblocking and congestion checks). There are
no behavior change except for the removal of two entries from one of the
ext4 tracing interface.The nonblocking checks in ->writepages are no longer used because the
flusher now prefer to block on get_request_wait() than to skip inodes on
IO congestion. The latter will lead to more seeky IO.The nonblocking checks in ->writepage are no longer used because it's
redundant with the WB_SYNC_NONE check.We no long set ->nonblocking in VM page out and page migration, because
a) it's effectively redundant with WB_SYNC_NONE in current code
b) it's old semantic of "Don't get stuck on request queues" is mis-behavior:
that would skip some dirty inodes on congestion and page out others, which
is unfair in terms of LRU age.Inspired by Christoph Hellwig. Thanks!
Signed-off-by: Wu Fengguang
Cc: Theodore Ts'o
Cc: David Howells
Cc: Sage Weil
Cc: Steve French
Cc: Chris Mason
Cc: Jens Axboe
Cc: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Oct, 2010
1 commit
-
…inux-2.6 into perf/urgent
23 Oct, 2010
1 commit
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: remove in_workqueue_context()
workqueue: Clarify that schedule_on_each_cpu is synchronous
memory_hotplug: drop spurious calls to flush_scheduled_work()
shpchp: update workqueue usage
pciehp: update workqueue usage
isdn/eicon: don't call flush_scheduled_work() from diva_os_remove_soft_isr()
workqueue: add and use WQ_MEM_RECLAIM flag
workqueue: fix HIGHPRI handling in keep_working()
workqueue: add queue_work and activate_work trace points
workqueue: prepare for more tracepoints
workqueue: implement flush[_delayed]_work_sync()
workqueue: factor out start_flush_work()
workqueue: cleanup flush/cancel functions
workqueue: implement alloc_ordered_workqueue()Fix up trivial conflict in fs/gfs2/main.c as per Tejun
22 Oct, 2010
1 commit
-
…/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (29 commits)
sched: Export account_system_vtime()
sched: Call tick_check_idle before __irq_enter
sched: Remove irq time from available CPU power
sched: Do not account irq time to current task
x86: Add IRQ_TIME_ACCOUNTING
sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time
sched: Add a PF flag for ksoftirqd identification
sched: Consolidate account_system_vtime extern declaration
sched: Fix softirq time accounting
sched: Drop group_capacity to 1 only if local group has extra capacity
sched: Force balancing on newidle balance if local group has capacity
sched: Set group_imb only a task can be pulled from the busiest cpu
sched: Do not consider SCHED_IDLE tasks to be cache hot
sched: Drop all load weight manipulation for RT tasks
sched: Create special class for stop/migrate work
sched: Unindent labels
sched: Comment updates: fix default latency and granularity numbers
tracing/sched: Add sched_pi_setprio tracepoint
sched: Give CPU bound RT tasks preference
sched: Try not to migrate higher priority RT tasks
...
21 Oct, 2010
1 commit
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With the addition of trace_softirq_raise() the softirq tracepoint got
even more convoluted. Why the tracepoints take two pointers to assign
an integer is beyond my comprehension.But adding an extra case which treats the first pointer as an unsigned
long when the second pointer is NULL including the back and forth
type casting is just horrible.Convert the softirq tracepoints to take a single unsigned int argument
for the softirq vector number and fix the call sites.Signed-off-by: Thomas Gleixner
LKML-Reference:
Acked-by: Peter Zijlstra
Acked-by: mathieu.desnoyers@efficios.com
Cc: Frederic Weisbecker
Cc: Steven Rostedt
05 Oct, 2010
2 commits
-
These two tracepoints allow tracking when and how a work is queued and
activated. This patch is based on Frederic's patch to add queue_work
trace point.Signed-off-by: Tejun Heo
Cc: Frederic Weisbecker -
Define workqueue_work event class and use it for workqueue_execute_end
trace point. Also, move trace/events/workqueue.h include downwards
such that all struct definitions are visible to it. This is to
prepare for more tracepoints and doesn't cause any functional change.Signed-off-by: Tejun Heo
Cc: Frederic Weisbecker
21 Sep, 2010
1 commit
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Add a tracepoint that shows the priority of a task being boosted
via priority inheritance.Cc: Gregory Haskins
Acked-by: Peter Zijlstra
Signed-off-by: Steven Rostedt
17 Sep, 2010
1 commit
-
This patch adds new generic events for dynamic power management
tracing:- clock events class: used for clock enable/disable and for
clock rate change,
- power_domain events class: used for power domains transitions.The OMAP architecture will be using the new events for PM debugging,
however the new events are made generic enough to be used by all
platforms.Signed-off-by: Jean Pihet
Acked-by: Thomas Renninger
Cc: discuss@lesswatts.org
Cc: linux-pm@lists.linux-foundation.org
Cc: Thomas Renninger
Cc: Arjan van de Ven
Cc: Peter Zijlstra
Cc: Len Brown
Cc: Kevin Hilman
LKML-Reference:
Signed-off-by: Ingo Molnar
07 Sep, 2010
4 commits
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This patch adds tracepoint to consume_skb and add trace_kfree_skb
before __kfree_skb in skb_free_datagram_locked and net_tx_action.
Combinating with tracepoint on dev_hard_start_xmit, we can check
how long it takes to free transmitted packets. And using it, we can
calculate how many packets driver had at that time. It is useful when
a drop of transmitted packet is a problem.sshd-6828 [000] 112689.258154: consume_skb: skbaddr=f2d99bb8
Signed-off-by: Koki Sanagi
Acked-by: David S. Miller
Acked-by: Neil Horman
Cc: Mathieu Desnoyers
Cc: Kaneshige Kenji
Cc: Izumo Taku
Cc: Kosaki Motohiro
Cc: Lai Jiangshan
Cc: Scott Mcmillan
Cc: Steven Rostedt
Cc: Eric Dumazet
LKML-Reference:
Signed-off-by: Frederic Weisbecker -
This patch adds tracepoint to dev_queue_xmit, dev_hard_start_xmit,
netif_rx and netif_receive_skb. These tracepoints help you to monitor
network driver's input/output.-0 [001] 112447.902030: netif_rx: dev=eth1 skbaddr=f3ef0900 len=84
-0 [001] 112447.902039: netif_receive_skb: dev=eth1 skbaddr=f3ef0900 len=84
sshd-6828 [000] 112447.903257: net_dev_queue: dev=eth4 skbaddr=f3fca538 len=226
sshd-6828 [000] 112447.903260: net_dev_xmit: dev=eth4 skbaddr=f3fca538 len=226 rc=0Signed-off-by: Koki Sanagi
Acked-by: David S. Miller
Acked-by: Neil Horman
Cc: Mathieu Desnoyers
Cc: Kaneshige Kenji
Cc: Izumo Taku
Cc: Kosaki Motohiro
Cc: Lai Jiangshan
Cc: Scott Mcmillan
Cc: Steven Rostedt
Cc: Eric Dumazet
LKML-Reference:
Signed-off-by: Frederic Weisbecker -
This patch converts trace_napi_poll from DECLARE_EVENT to TRACE_EVENT
to improve the usability of napi_poll tracepoint.-0 [001] 241302.750777: napi_poll: napi poll on napi struct f6acc480 for device eth3
-0 [000] 241302.852389: napi_poll: napi poll on napi struct f5d0d70c for device eth1The original patch is below:
http://marc.info/?l=linux-kernel&m=126021713809450&w=2[ sanagi.koki@jp.fujitsu.com: And add a fix by Steven Rostedt:
http://marc.info/?l=linux-kernel&m=126150506519173&w=2 ]Signed-off-by: Neil Horman
Acked-by: David S. Miller
Acked-by: Neil Horman
Cc: Mathieu Desnoyers
Cc: Kaneshige Kenji
Cc: Izumo Taku
Cc: Kosaki Motohiro
Cc: Lai Jiangshan
Cc: Scott Mcmillan
Cc: Steven Rostedt
Cc: Eric Dumazet
LKML-Reference:
Signed-off-by: Koki Sanagi
Signed-off-by: Frederic Weisbecker -
Add a tracepoint for tracing when softirq action is raised.
This and the existing tracepoints complete softirq's tracepoints:
softirq_raise, softirq_entry and softirq_exit.And when this tracepoint is used in combination with
the softirq_entry tracepoint we can determine
the softirq raise latency.Signed-off-by: Lai Jiangshan
Acked-by: Mathieu Desnoyers
Acked-by: Neil Horman
Cc: David Miller
Cc: Kaneshige Kenji
Cc: Izumo Taku
Cc: Kosaki Motohiro
Cc: Lai Jiangshan
Cc: Scott Mcmillan
Cc: Steven Rostedt
Cc: Eric Dumazet
LKML-Reference:
[ factorize softirq events with DECLARE_EVENT_CLASS ]
Signed-off-by: Koki Sanagi
Signed-off-by: Frederic Weisbecker
25 Aug, 2010
1 commit
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…/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
watchdog: Don't throttle the watchdog
tracing: Fix timer tracing
22 Aug, 2010
1 commit
-
With the introduction of the new unified work queue thread pools,
we lost one feature: It's no longer possible to know which worker
is causing the CPU to wake out of idle. The result is that PowerTOP
now reports a lot of "kworker/a:b" instead of more readable results.This patch adds a pair of tracepoints to the new workqueue code,
similar in style to the timer/hrtimer tracepoints.With this pair of tracepoints, the next PowerTOP can correctly
report which work item caused the wakeup (and how long it took):Interrupt (43) i915 time 3.51ms wakeups 141
Work ieee80211_iface_work time 0.81ms wakeups 29
Work do_dbs_timer time 0.55ms wakeups 24
Process Xorg time 21.36ms wakeups 4
Timer sched_rt_period_timer time 0.01ms wakeups 1Signed-off-by: Arjan van de Ven
Signed-off-by: Linus Torvalds
19 Aug, 2010
1 commit
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PowerTOP would like to be able to trace timers.
Unfortunately, the current timer tracing is not very useful: the
actual timer function is not recorded in the trace at the start
of timer execution.Although this is recorded for timer "start" time (when it gets
armed), this is not useful; most timers get started early, and a
tracer like PowerTOP will never see this event, but will only
see the actual running of the timer.This patch just adds the function to the timer tracing; I've
verified with PowerTOP that now it can get useful information
about timers.Signed-off-by: Arjan van de Ven
Cc: xiaoguangrong@cn.fujitsu.com
Cc: Steven Rostedt
Cc: Frederic Weisbecker
Cc: Peter Zijlstra
Cc: # .35.x, .34.x, .33.x
LKML-Reference:
Signed-off-by: Ingo Molnar
11 Aug, 2010
1 commit
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* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits)
block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n
xen-blkfront: fix missing out label
blkdev: fix blkdev_issue_zeroout return value
block: update request stacking methods to support discards
block: fix missing export of blk_types.h
writeback: fix bad _bh spinlock nesting
drbd: revert "delay probes", feature is being re-implemented differently
drbd: Initialize all members of sync_conf to their defaults [Bugz 315]
drbd: Disable delay probes for the upcomming release
writeback: cleanup bdi_register
writeback: add new tracepoints
writeback: remove unnecessary init_timer call
writeback: optimize periodic bdi thread wakeups
writeback: prevent unnecessary bdi threads wakeups
writeback: move bdi threads exiting logic to the forker thread
writeback: restructure bdi forker loop a little
writeback: move last_active to bdi
writeback: do not remove bdi from bdi_list
writeback: simplify bdi code a little
writeback: do not lose wake-ups in bdi threads
...Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and
drivers/scsi/scsi_error.c as per Jens.
10 Aug, 2010
7 commits
-
Memcg also need to trace page isolation information as global reclaim.
This patch does it.Signed-off-by: KOSAKI Motohiro
Reviewed-by: KAMEZAWA Hiroyuki
Acked-by: Mel Gorman
Acked-by: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Mel Gorman recently added some vmscan tracepoints. Unfortunately they are
covered only global reclaim. But we want to trace memcg reclaim too.Thus, this patch convert them to DEFINE_TRACE macro. it help to reuse
tracepoint definition for other similar usage (i.e. memcg). This patch
have no functionally change.Signed-off-by: KOSAKI Motohiro
Reviewed-by: KAMEZAWA Hiroyuki
Acked-by: Balbir Singh
Acked-by: Mel Gorman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Memcg also need to trace reclaim progress as direct reclaim. This patch
add it.Signed-off-by: KOSAKI Motohiro
Reviewed-by: KAMEZAWA Hiroyuki
Acked-by: Mel Gorman
Acked-by: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Mel Gorman recently added some vmscan tracepoints. Unfortunately they are
covered only global reclaim. But we want to trace memcg reclaim too.Thus, this patch convert them to DEFINE_TRACE macro. it help to reuse
tracepoint definition for other similar usage (i.e. memcg). This patch
have no functionally change.Signed-off-by: KOSAKI Motohiro
Reviewed-by: KAMEZAWA Hiroyuki
Acked-by: Mel Gorman
Acked-by: Balbir Singh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a trace event for when page reclaim queues a page for IO and records
whether it is synchronous or asynchronous. Excessive synchronous IO for a
process can result in noticeable stalls during direct reclaim. Excessive
IO from page reclaim may indicate that the system is seriously under
provisioned for the amount of dirty pages that exist.Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Acked-by: Larry Woodman
Cc: Dave Chinner
Cc: Chris Mason
Cc: Nick Piggin
Cc: Rik van Riel
Cc: Johannes Weiner
Cc: Christoph Hellwig
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Andrea Arcangeli
Cc: Michael Rubin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add an event for when pages are isolated en-masse from the LRU lists.
This event augments the information available on LRU traffic and can be
used to evaluate lumpy reclaim.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Acked-by: Larry Woodman
Cc: Dave Chinner
Cc: Chris Mason
Cc: Nick Piggin
Cc: Rik van Riel
Cc: Johannes Weiner
Cc: Christoph Hellwig
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Andrea Arcangeli
Cc: Michael Rubin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add two trace events for kswapd waking up and going asleep for the
purposes of tracking kswapd activity and two trace events for direct
reclaim beginning and ending. The information can be used to work out how
much time a process or the system is spending on the reclamation of pages
and in the case of direct reclaim, how many pages were reclaimed for that
process. High frequency triggering of these events could point to memory
pressure problems.Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Acked-by: Larry Woodman
Cc: Dave Chinner
Cc: Chris Mason
Cc: Nick Piggin
Cc: Rik van Riel
Cc: Johannes Weiner
Cc: Christoph Hellwig
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Cc: Andrea Arcangeli
Cc: Michael Rubin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Aug, 2010
5 commits
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* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (40 commits)
ext4: Adding error check after calling ext4_mb_regular_allocator()
ext4: Fix dirtying of journalled buffers in data=journal mode
ext4: re-inline ext4_rec_len_(to|from)_disk functions
jbd2: Remove t_handle_lock from start_this_handle()
jbd2: Change j_state_lock to be a rwlock_t
jbd2: Use atomic variables to avoid taking t_handle_lock in jbd2_journal_stop
ext4: Add mount options in superblock
ext4: force block allocation on quota_off
ext4: fix freeze deadlock under IO
ext4: drop inode from orphan list if ext4_delete_inode() fails
ext4: check to make make sure bd_dev is set before dereferencing it
jbd2: Make barrier messages less scary
ext4: don't print scary messages for allocation failures post-abort
ext4: fix EFBIG edge case when writing to large non-extent file
ext4: fix ext4_get_blocks references
ext4: Always journal quota file modifications
ext4: Fix potential memory leak in ext4_fill_super
ext4: Don't error out the fs if the user tries to make a file too big
ext4: allocate stripe-multiple IOs on stripe boundaries
ext4: move aio completion after unwritten extent conversion
...Fix up conflicts in fs/ext4/inode.c as per Ted.
Fix up xfs conflicts as per earlier xfs merge.
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (55 commits)
workqueue: mark init_workqueues() as early_initcall()
workqueue: explain for_each_*cwq_cpu() iterators
fscache: fix build on !CONFIG_SYSCTL
slow-work: kill it
gfs2: use workqueue instead of slow-work
drm: use workqueue instead of slow-work
cifs: use workqueue instead of slow-work
fscache: drop references to slow-work
fscache: convert operation to use workqueue instead of slow-work
fscache: convert object to use workqueue instead of slow-work
workqueue: fix how cpu number is stored in work->data
workqueue: fix mayday_mask handling on UP
workqueue: fix build problem on !CONFIG_SMP
workqueue: fix locking in retry path of maybe_create_worker()
async: use workqueue for worker pool
workqueue: remove WQ_SINGLE_CPU and use WQ_UNBOUND instead
workqueue: implement unbound workqueue
workqueue: prepare for WQ_UNBOUND implementation
libata: take advantage of cmwq and remove concurrency limitations
workqueue: fix worker management invocation without pending works
...Fixed up conflicts in fs/cifs/* as per Tejun. Other trivial conflicts in
include/linux/workqueue.h, kernel/trace/Kconfig and kernel/workqueue.c -
Add 2 new trace points to the periodic write-back wake up case, just like we do
in the 'bdi_queue_work()' function. Namely, introduce:1. trace_writeback_wake_thread(bdi)
2. trace_writeback_wake_forker_thread(bdi)The first event is triggered every time we wake up a bdi thread to start
periodic background write-out. The second event is triggered only when the bdi
thread does not exist and should be created by the forker thread.This patch was suggested by Dave Chinner and Christoph Hellwig.
Signed-off-by: Artem Bityutskiy
Signed-off-by: Jens Axboe -
include/trace/events/writeback.h uses dev_name(), so it needs to
include linux/device.h.include/trace/events/writeback.h:12: error: implicit declaration of function 'dev_name'
Signed-off-by: Randy Dunlap
Signed-off-by: Jens Axboe -
Add a trace event to the ->writepage loop in write_cache_pages to give
visibility into how the ->writepage call is changing variables within the
writeback control structure. Of most interest is how wbc->nr_to_write changes
from call to call, especially with filesystems that write multiple pages
in ->writepage.Signed-off-by: Dave Chinner
Reviewed-by: Christoph Hellwig
Signed-off-by: Jens Axboe
