docs: ftrace: always use canonical ftrace path

The canonical location for the tracefs filesystem is at /sys/kernel/tracing.

But, from Documentation/trace/ftrace.rst:

Before 4.1, all ftrace traci

docs: ftrace: always use canonical ftrace path

The canonical location for the tracefs filesystem is at /sys/kernel/tracing.

But, from Documentation/trace/ftrace.rst:

Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:

/sys/kernel/debug/tracing

Many parts of Documentation still reference this older debugfs path, so
let's update them to avoid confusion.

Signed-off-by: Ross Zwisler <zwisler@google.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20230125213251.2013791-1-zwisler@google.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

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tweewide: Fix most Shebang lines

Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every distro has everything under /usr/bin,
sometimes not even bash.

tweewide: Fix most Shebang lines

Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every distro has everything under /usr/bin,
sometimes not even bash.

Signed-off-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

show more ...

tweewide: Fix most Shebang lines

commit c25ce589dca10d64dde139ae093abc258a32869c upstream.

Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every dist

tweewide: Fix most Shebang lines

commit c25ce589dca10d64dde139ae093abc258a32869c upstream.

Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every distro has everything under /usr/bin,
sometimes not even bash.

Signed-off-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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mm: move recent_rotated pages calculation to shrink_inactive_list()

Patch series "mm: Generalize putback functions"]

putback_inactive_pages() and move_active_pages_to_lru() are almost
similar, so t

mm: move recent_rotated pages calculation to shrink_inactive_list()

Patch series "mm: Generalize putback functions"]

putback_inactive_pages() and move_active_pages_to_lru() are almost
similar, so this patchset merges them ina single function.

This patch (of 4):

The patch moves the calculation from putback_inactive_pages() to
shrink_inactive_list(). This makes putback_inactive_pages() looking more
similar to move_active_pages_to_lru().

To do that, we account activated pages in reclaim_stat::nr_activate.
Since a page may change its LRU type from anon to file cache inside
shrink_page_list() (see ClearPageSwapBacked()), we have to account pages
for the both types. So, nr_activate becomes an array.

Previously we used nr_activate to account PGACTIVATE events, but now we
account them into pgactivate variable (since they are about number of
pages in general, not about sum of hpage_nr_pages).

Link: http://lkml.kernel.org/r/155290127956.31489.3393586616054413298.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory

Kswapd will not wakeup if per-zone watermarks are not failing or if too
many previous attempts at background reclaim have fail

mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory

Kswapd will not wakeup if per-zone watermarks are not failing or if too
many previous attempts at background reclaim have failed.

This can be true if there is a lot of free memory available. For high-
order allocations, kswapd is responsible for waking up kcompactd for
background compaction. If the zone is not below its watermarks or
reclaim has recently failed (lots of free memory, nothing left to
reclaim), kcompactd does not get woken up.

When __GFP_DIRECT_RECLAIM is not allowed, allow kcompactd to still be
woken up even if kswapd will not reclaim. This allows high-order
allocations, such as thp, to still trigger background compaction even
when the zone has an abundance of free memory.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803111659420.209721@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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trace-vmscan-postprocess: sync with tracepoints updates

Both mm_vmscan_lru_shrink_active and mm_vmscan_lru_isolate have changed
so the script needs to be update to reflect those changes

Link: http:

trace-vmscan-postprocess: sync with tracepoints updates

Both mm_vmscan_lru_shrink_active and mm_vmscan_lru_isolate have changed
so the script needs to be update to reflect those changes

Link: http://lkml.kernel.org/r/20170105151737.GU21618@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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mm: trace-vmscan-postprocess.pl: report the number of file/anon pages respectively

Until now, the reporting from trace-vmscan-postprocess.pl is not very
useful because we cannot directly use this sc

mm: trace-vmscan-postprocess.pl: report the number of file/anon pages respectively

Until now, the reporting from trace-vmscan-postprocess.pl is not very
useful because we cannot directly use this script for checking the
file/anon ratio of scanning. This patch aims to report respectively the
number of file/anon pages which were scanned/reclaimed by kswapd or
direct-reclaim. Sample output is usually something like the following.

Summary
Direct reclaims: 8823
Direct reclaim pages scanned: 2438797
Direct reclaim file pages scanned: 1315200
Direct reclaim anon pages scanned: 1123597
Direct reclaim pages reclaimed: 446139
Direct reclaim file pages reclaimed: 378668
Direct reclaim anon pages reclaimed: 67471
Direct reclaim write file sync I/O: 0
Direct reclaim write anon sync I/O: 0
Direct reclaim write file async I/O: 0
Direct reclaim write anon async I/O: 4240
Wake kswapd requests: 122310
Time stalled direct reclaim: 13.78 seconds

Kswapd wakeups: 25817
Kswapd pages scanned: 170779115
Kswapd file pages scanned: 162725123
Kswapd anon pages scanned: 8053992
Kswapd pages reclaimed: 129065738
Kswapd file pages reclaimed: 128500930
Kswapd anon pages reclaimed: 564808
Kswapd reclaim write file sync I/O: 0
Kswapd reclaim write anon sync I/O: 0
Kswapd reclaim write file async I/O: 36
Kswapd reclaim write anon async I/O: 730730
Time kswapd awake: 1015.50 seconds

Signed-off-by: Chen Yucong <slaoub@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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mm:vmscan: update the trace-vmscan-postprocess.pl for event vmscan/mm_vmscan_lru_isolate

When using trace-vmscan-postprocess.pl for checking the file/anon rate
of scanning, we can find that it can n

mm:vmscan: update the trace-vmscan-postprocess.pl for event vmscan/mm_vmscan_lru_isolate

When using trace-vmscan-postprocess.pl for checking the file/anon rate
of scanning, we can find that it can not be performed. At the same
time, the following message will be reported:

WARNING: Format not as expected for event vmscan/mm_vmscan_lru_isolate
'file' != 'contig_taken' Fewer fields than expected in format at
./trace-vmscan-postprocess.pl line 171, <FORMAT> line 76.

In trace-vmscan-postprocess.pl, (contig_taken, contig_dirty, and
contig_failed) are be associated respectively to (nr_lumpy_taken,
nr_lumpy_dirty, and nr_lumpy_failed) for lumpy reclaim. Via commit
c53919adc045 ("mm: vmscan: remove lumpy reclaim"), lumpy reclaim had
already been removed by Mel, but the update for
trace-vmscan-postprocess.pl was missed.

Signed-off-by: Chen Yucong <slaoub@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Documentation/trace/postprocess/trace-vmscan-postprocess.pl: fix the traceevent regex

When irq, preempt and lockdep fields are printed (field 3 in the example
below) in the trace output, the script

Documentation/trace/postprocess/trace-vmscan-postprocess.pl: fix the traceevent regex

When irq, preempt and lockdep fields are printed (field 3 in the example
below) in the trace output, the script fails.

An example entry:
kswapd0-610 [000] ...1 158.112152: mm_vmscan_kswapd_wake: nid=0 order=0

Signed-off-by: Vinayak Menon <vinayakm.list@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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mm: change isolate mode from #define to bitwise type

Change ISOLATE_XXX macro with bitwise isolate_mode_t type. Normally,
macro isn't recommended as it's type-unsafe and making debugging harder as

mm: change isolate mode from #define to bitwise type

Change ISOLATE_XXX macro with bitwise isolate_mode_t type. Normally,
macro isn't recommended as it's type-unsafe and making debugging harder as
symbol cannot be passed throught to the debugger.

Quote from Johannes
" Hmm, it would probably be cleaner to fully convert the isolation mode
into independent flags. INACTIVE, ACTIVE, BOTH is currently a
tri-state among flags, which is a bit ugly."

This patch moves isolate mode from swap.h to mmzone.h by memcontrol.h

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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mm: vmscan: tracepoint: account for scanned pages similarly for both ftrace and vmstat

When correlating ftrace results with /proc/vmstat, I noticed that the
reporting scripts value for "pages scanne

mm: vmscan: tracepoint: account for scanned pages similarly for both ftrace and vmstat

When correlating ftrace results with /proc/vmstat, I noticed that the
reporting scripts value for "pages scanned" differed significantly. Both
values were "right" depending on how you look at it.

The difference is due to vmstat only counting scanning of the inactive
list towards pages scanned. The analysis script for the tracepoint counts
active and inactive list yielding a far higher value than vmstat. The
resulting scanning/reclaim ratio looks much worse. The tracepoint is ok
but this patch updates the reporting script so that the report values for
scanned are similar to vmstat.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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tracing, vmscan: add trace events for LRU list shrinking

There have been numerous reports of stalls that pointed at the problem
being somewhere in the VM. There are multiple roots to the problems w

tracing, vmscan: add trace events for LRU list shrinking

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 were

X86: Intel P4 2-core
X86-64: AMD Phenom 4-core
PPC64: PPC970MP

Each 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-rc4

traceonly-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 congested

nocongest-v1r5: Patches 1-3 for testing wait_iff_congestion
nodirect-v1r5: Patches 1-10 to disable filesystem writeback for better IO

The tests run were as follows

kernbench
compile-based benchmark. Smoke test performance

sysbench
OLTP read-only benchmark. Will be re-run in the future as read-write

micro-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 10.19

Total 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 0

The 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 12.76

Overall, 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 23.90

Total 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 0

The 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 30.88

With 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 1176.82

Total 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.ps

FTrace 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 9

Overall, 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 3765.39

With 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 1328.88

Total 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 0

Not 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 3229.85

The 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 <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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

vmscan: tracing: add a postprocessing script for reclaim-related ftrace events

Add a simple post-processing script for the reclaim-related trace events.
It can be used to give an indication of how m

vmscan: tracing: add a postprocessing script for reclaim-related ftrace events

Add a simple post-processing script for the reclaim-related trace events.
It can be used to give an indication of how much traffic there is on the
LRU lists and how severe latencies due to reclaim are. Example output
looks like the following

Reclaim latencies expressed as order-latency_in_ms
uname-3942 9-200.179000000004 9-98.7900000000373 9-99.8330000001006
kswapd0-311 0-662.097999999998 0-2.79700000002049 \
0-149.100000000035 0-3295.73600000003 0-9806.31799999997 0-35528.833 \
0-10043.197 0-129740.979 0-3.50500000000466 0-3.54899999999907 \
0-9297.78999999992 0-3.48499999998603 0-3596.97999999998 0-3.92799999995623 \
0-3.35000000009313 0-16729.017 0-3.57799999997951 0-47435.0630000001 \
0-3.7819999998901 0-5864.06999999995 0-18635.334 0-10541.289 9-186011.565 \
9-3680.86300000001 9-1379.06499999994 9-958571.115 9-66215.474 \
9-6721.14699999988 9-1962.15299999993 9-1094806.125 9-2267.83199999994 \
9-47120.9029999999 9-427653.886 9-2.6359999999404 9-632.148999999976 \
9-476.753000000026 9-495.577000000048 9-8.45900000003166 9-6.6820000000298 \
9-1.30500000016764 9-251.746000000043 9-383.905000000028 9-80.1419999999925 \
9-281.160000000149 9-14.8780000000261 9-381.45299999998 9-512.07799999998 \
9-49.5519999999087 9-167.439000000013 9-183.820999999996 9-239.527999999933 \
9-19.9479999998584 9-148.747999999905 9-164.583000000101 9-16.9480000000913 \
9-192.376000000164 9-64.1010000000242 9-1.40800000005402 9-3.60800000000745 \
9-17.1359999999404 9-4.69500000006519 9-2.06400000001304 9-1582488.554 \
9-6244.19499999983 9-348153.812 9-2.0999999998603 9-0.987999999895692 \
0-32218.473 0-1.6140000000596 0-1.28100000019185 0-1.41300000017509 \
0-1.32299999985844 0-602.584000000032 0-1.34400000004098 0-1.6929999999702 \
1-22101.8190000001 9-174876.724 9-16.2420000000857 9-175.165999999736 \
9-15.8589999997057 9-0.604999999981374 9-3061.09000000032 9-479.277000000235 \
9-1.54499999992549 9-771.985000000335 9-4.88700000010431 9-15.0649999999441 \
9-0.879999999888241 9-252.01500000013 9-1381.03600000031 9-545.689999999944 \
9-3438.0129999998 9-3343.70099999988
bench-stresshig-3942 9-7063.33900000004 9-129960.482 9-2062.27500000002 \
9-3845.59399999992 9-171.82799999998 9-16493.821 9-7615.23900000006 \
9-10217.848 9-983.138000000035 9-2698.39999999991 9-4016.1540000001 \
9-5522.37700000009 9-21630.429 \
9-15061.048 9-10327.953 9-542.69700000016 9-317.652000000002 \
9-8554.71699999995 9-1786.61599999992 9-1899.31499999994 9-2093.41899999999 \
9-4992.62400000007 9-942.648999999976 9-1923.98300000001 9-3.7980000001844 \
9-5.99899999983609 9-0.912000000011176 9-1603.67700000014 9-1.98300000000745 \
9-3.96500000008382 9-0.902999999932945 9-2802.72199999983 9-1078.24799999991 \
9-2155.82900000014 9-10.058999999892 9-1984.723 9-1687.97999999998 \
9-1136.05300000007 9-3183.61699999985 9-458.731000000145 9-6.48600000003353 \
9-1013.25200000009 9-8415.22799999989 9-10065.584 9-2076.79600000009 \
9-3792.65699999989 9-71.2010000001173 9-2560.96999999997 9-2260.68400000012 \
9-2862.65799999982 9-1255.81500000018 9-15.7440000001807 9-4.33499999996275 \
9-1446.63800000004 9-238.635000000009 9-60.1790000000037 9-4.38800000003539 \
9-639.567000000039 9-306.698000000091 9-31.4070000001229 9-74.997999999905 \
9-632.725999999791 9-1625.93200000003 9-931.266000000061 9-98.7749999999069 \
9-984.606999999844 9-225.638999999966 9-421.316000000108 9-653.744999999879 \
9-572.804000000004 9-769.158999999985 9-603.918000000063 9-4.28499999991618 \
9-626.21399999992 9-1721.25 9-0.854999999981374 9-572.39599999995 \
9-681.881999999983 9-1345.12599999993 9-363.666999999899 9-3823.31099999999 \
9-2991.28200000012 9-4.27099999994971 9-309.76500000013 9-3068.35700000008 \
9-788.25 9-3515.73999999999 9-2065.96100000013 9-286.719999999972 \
9-316.076000000117 9-344.151000000071 9-2.51000000000931 9-306.688000000082 \
9-1515.00099999993 9-336.528999999864 9-793.491999999853 9-457.348999999929 \
9-13620.155 9-119.933999999892 9-35.0670000000391 9-918.266999999993 \
9-828.569000000134 9-4863.81099999999 9-105.222000000067 9-894.23900000006 \
9-110.964999999851 9-0.662999999942258 9-12753.3150000002 9-12.6129999998957 \
9-13368.0899999999 9-12.4199999999255 9-1.00300000002608 9-1.41100000008009 \
9-10300.5290000001 9-16.502000000095 9-30.7949999999255 9-6283.0140000002 \
9-4320.53799999994 9-6826.27300000004 9-3.07299999985844 9-1497.26799999992 \
9-13.4040000000969 9-3.12999999988824 9-3.86100000003353 9-11.3539999998175 \
9-0.10799999977462 9-21.780999999959 9-209.695999999996 9-299.647000000114 \
9-6.01699999999255 9-20.8349999999627 9-22.5470000000205 9-5470.16800000006 \
9-7.60499999998137 9-0.821000000229105 9-1.56600000010803 9-14.1669999998994 \
9-0.209000000031665 9-1.82300000009127 9-1.70000000018626 9-19.9429999999702 \
9-124.266999999993 9-0.0389999998733401 9-6.71400000015274 9-16.7710000001825 \
9-31.0409999999683 9-0.516999999992549 9-115.888000000035 9-5.19900000002235 \
9-222.389999999898 9-11.2739999999758 9-80.9050000000279 9-8.14500000001863 \
9-4.44599999999627 9-0.218999999808148 9-0.715000000083819 9-0.233000000007451
\
9-48.2630000000354 9-248.560999999987 9-374.96800000011 9-644.179000000004 \
9-0.835999999893829 9-79.0060000000522 9-128.447999999858 9-0.692000000039116 \
9-5.26500000013039 9-128.449000000022 9-2.04799999995157 9-12.0990000001621 \
9-8.39899999997579 9-10.3860000001732 9-11.9310000000987 9-53.4450000000652 \
9-0.46999999997206 9-2.96299999998882 9-17.9699999999721 9-0.776000000070781 \
9-25.2919999998994 9-33.1110000000335 9-0.434000000124797 9-0.641000000061467 \
9-0.505000000121072 9-1.12800000002608 9-149.222000000067 9-1.17599999997765 \
9-3247.33100000001 9-10.7439999999478 9-153.523000000045 9-1.38300000014715 \
9-794.762000000104 9-3.36199999996461 9-128.765999999829 9-181.543999999994 \
9-78149.8229999999 9-176.496999999974 9-89.9940000001807 9-9.12700000009499 \
9-250.827000000048 9-0.224999999860302 9-0.388999999966472 9-1.16700000036508 \
9-32.1740000001155 9-12.6800000001676 9-0.0720000001601875 9-0.274999999906868
\
9-0.724000000394881 9-266.866000000387 9-45.5709999999963 9-4.54399999976158 \
9-8.27199999988079 9-4.38099999958649 9-0.512000000104308 9-0.0640000002458692
\
9-5.20000000018626 9-0.0839999997988343 9-12.816000000108 9-0.503000000026077 \
9-0.507999999914318 9-6.23999999975786 9-3.35100000025705 9-18.8530000001192 \
9-25.2220000000671 9-68.2309999996796 9-98.9939999999478 9-0.441000000108033 \
9-4.24599999981001 9-261.702000000048 9-3.01599999982864 9-0.0749999997206032 \
9-0.0370000000111759 9-4.375 9-3.21800000034273 9-11.3960000001825 \
9-0.0540000000037253 9-0.286000000312924 9-0.865999999921769 \
9-0.294999999925494 9-6.45999999996275 9-4.31099999975413 9-128.248999999836 \
9-0.282999999821186 9-102.155000000261 9-0.0860000001266599 \
9-0.0540000000037253 9-0.935000000055879 9-0.0670000002719462 \
9-5.8640000000596 9-19.9860000000335 9-4.18699999991804 9-0.566000000108033 \
9-2.55099999997765 9-0.702000000048429 9-131.653999999631 9-0.638999999966472 \
9-14.3229999998584 9-183.398000000045 9-178.095999999903 9-3.22899999981746 \
9-7.31399999978021 9-22.2400000002235 9-11.7979999999516 9-108.10599999968 \
9-99.0159999998286 9-102.640999999829 9-38.414000000339
Process Direct Wokeup Pages Pages Pages
details Rclms Kswapd Scanned Sync-IO ASync-IO
cc1-30800 0 1 0 0 0 wakeup-0=1
cc1-24260 0 1 0 0 0 wakeup-0=1
cc1-24152 0 12 0 0 0 wakeup-0=12
cc1-8139 0 1 0 0 0 wakeup-0=1
cc1-4390 0 1 0 0 0 wakeup-0=1
cc1-4648 0 7 0 0 0 wakeup-0=7
cc1-4552 0 3 0 0 0 wakeup-0=3
dd-4550 0 31 0 0 0 wakeup-0=31
date-4898 0 1 0 0 0 wakeup-0=1
cc1-6549 0 7 0 0 0 wakeup-0=7
as-22202 0 17 0 0 0 wakeup-0=17
cc1-6495 0 9 0 0 0 wakeup-0=9
cc1-8299 0 1 0 0 0 wakeup-0=1
cc1-6009 0 1 0 0 0 wakeup-0=1
cc1-2574 0 2 0 0 0 wakeup-0=2
cc1-30568 0 1 0 0 0 wakeup-0=1
cc1-2679 0 6 0 0 0 wakeup-0=6
sh-13747 0 12 0 0 0 wakeup-0=12
cc1-22193 0 18 0 0 0 wakeup-0=18
cc1-30725 0 2 0 0 0 wakeup-0=2
as-4392 0 2 0 0 0 wakeup-0=2
cc1-28180 0 14 0 0 0 wakeup-0=14
cc1-13697 0 2 0 0 0 wakeup-0=2
cc1-22207 0 8 0 0 0 wakeup-0=8
cc1-15270 0 179 0 0 0 wakeup-0=179
cc1-22011 0 82 0 0 0 wakeup-0=82
cp-14682 0 1 0 0 0 wakeup-0=1
as-11926 0 2 0 0 0 wakeup-0=2
cc1-6016 0 5 0 0 0 wakeup-0=5
make-18554 0 13 0 0 0 wakeup-0=13
cc1-8292 0 12 0 0 0 wakeup-0=12
make-24381 0 1 0 0 0 wakeup-1=1
date-18681 0 33 0 0 0 wakeup-0=33
cc1-32276 0 1 0 0 0 wakeup-0=1
timestamp-outpu-2809 0 253 0 0 0 wakeup-0=240 wakeup-1=13
date-18624 0 7 0 0 0 wakeup-0=7
cc1-30960 0 9 0 0 0 wakeup-0=9
cc1-4014 0 1 0 0 0 wakeup-0=1
cc1-30706 0 22 0 0 0 wakeup-0=22
uname-3942 4 1 306 0 17 direct-9=4 wakeup-9=1
cc1-28207 0 1 0 0 0 wakeup-0=1
cc1-30563 0 9 0 0 0 wakeup-0=9
cc1-22214 0 10 0 0 0 wakeup-0=10
cc1-28221 0 11 0 0 0 wakeup-0=11
cc1-28123 0 6 0 0 0 wakeup-0=6
kswapd0-311 0 7 357302 0 34233 wakeup-0=7
cc1-5988 0 7 0 0 0 wakeup-0=7
as-30734 0 161 0 0 0 wakeup-0=161
cc1-22004 0 45 0 0 0 wakeup-0=45
date-4590 0 4 0 0 0 wakeup-0=4
cc1-15279 0 213 0 0 0 wakeup-0=213
date-30735 0 1 0 0 0 wakeup-0=1
cc1-30583 0 4 0 0 0 wakeup-0=4
cc1-32324 0 2 0 0 0 wakeup-0=2
cc1-23933 0 3 0 0 0 wakeup-0=3
cc1-22001 0 36 0 0 0 wakeup-0=36
bench-stresshig-3942 287 287 80186 6295 12196 direct-9=287 wakeup-9=287
cc1-28170 0 7 0 0 0 wakeup-0=7
date-7932 0 92 0 0 0 wakeup-0=92
cc1-22222 0 6 0 0 0 wakeup-0=6
cc1-32334 0 16 0 0 0 wakeup-0=16
cc1-2690 0 6 0 0 0 wakeup-0=6
cc1-30733 0 9 0 0 0 wakeup-0=9
cc1-32298 0 2 0 0 0 wakeup-0=2
cc1-13743 0 18 0 0 0 wakeup-0=18
cc1-22186 0 4 0 0 0 wakeup-0=4
cc1-28214 0 11 0 0 0 wakeup-0=11
cc1-13735 0 1 0 0 0 wakeup-0=1
updatedb-8173 0 18 0 0 0 wakeup-0=18
cc1-13750 0 3 0 0 0 wakeup-0=3
cat-2808 0 2 0 0 0 wakeup-0=2
cc1-15277 0 169 0 0 0 wakeup-0=169
date-18317 0 1 0 0 0 wakeup-0=1
cc1-15274 0 197 0 0 0 wakeup-0=197
cc1-30732 0 1 0 0 0 wakeup-0=1

Kswapd Kswapd Order Pages Pages Pages
Instance Wakeups Re-wakeup Scanned Sync-IO ASync-IO
kswapd0-311 91 24 357302 0 34233 wake-0=31 wake-1=1 wake-9=59 rewake-0=10 rewake-1=1 rewake-9=13

Summary
Direct reclaims: 291
Direct reclaim pages scanned: 437794
Direct reclaim write sync I/O: 6295
Direct reclaim write async I/O: 46446
Wake kswapd requests: 2152
Time stalled direct reclaim: 519.163009000002 ms

Kswapd wakeups: 91
Kswapd pages scanned: 357302
Kswapd reclaim write sync I/O: 0
Kswapd reclaim write async I/O: 34233
Time kswapd awake: 5282.749757 ms

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Larry Woodman <lwoodman@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michael Rubin <mrubin@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

tweewide: Fix most Shebang lines

commit c25ce589dca10d64dde139ae093abc258a32869c upstream.

Change every shebang which does not need an argument to use /usr/bin/env.
This is need

tweewide: Fix most Shebang lines

commit c25ce589dca10d64dde139ae093abc258a32869c upstream.

Change every shebang which does not need an argument to use /usr/bin/env.
This is needed as not every distro has everything under /usr/bin,
sometimes not even bash.

Signed-off-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

mm: move recent_rotated pages calculation to shrink_inactive_list()

Patch series "mm: Generalize putback functions"]

putback_inactive_pages() and move_active_pages_to_lru() are almo

mm: move recent_rotated pages calculation to shrink_inactive_list()

Patch series "mm: Generalize putback functions"]

putback_inactive_pages() and move_active_pages_to_lru() are almost
similar, so this patchset merges them ina single function.

This patch (of 4):

The patch moves the calculation from putback_inactive_pages() to
shrink_inactive_list(). This makes putback_inactive_pages() looking more
similar to move_active_pages_to_lru().

To do that, we account activated pages in reclaim_stat::nr_activate.
Since a page may change its LRU type from anon to file cache inside
shrink_page_list() (see ClearPageSwapBacked()), we have to account pages
for the both types. So, nr_activate becomes an array.

Previously we used nr_activate to account PGACTIVATE events, but now we
account them into pgactivate variable (since they are about number of
pages in general, not about sum of hpage_nr_pages).

Link: http://lkml.kernel.org/r/155290127956.31489.3393586616054413298.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory

Kswapd will not wakeup if per-zone watermarks are not failing or if too
many previous attempts at background recla

mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory

Kswapd will not wakeup if per-zone watermarks are not failing or if too
many previous attempts at background reclaim have failed.

This can be true if there is a lot of free memory available. For high-
order allocations, kswapd is responsible for waking up kcompactd for
background compaction. If the zone is not below its watermarks or
reclaim has recently failed (lots of free memory, nothing left to
reclaim), kcompactd does not get woken up.

When __GFP_DIRECT_RECLAIM is not allowed, allow kcompactd to still be
woken up even if kswapd will not reclaim. This allows high-order
allocations, such as thp, to still trigger background compaction even
when the zone has an abundance of free memory.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1803111659420.209721@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

trace-vmscan-postprocess: sync with tracepoints updates

Both mm_vmscan_lru_shrink_active and mm_vmscan_lru_isolate have changed
so the script needs to be update to reflect those changes

trace-vmscan-postprocess: sync with tracepoints updates

Both mm_vmscan_lru_shrink_active and mm_vmscan_lru_isolate have changed
so the script needs to be update to reflect those changes

Link: http://lkml.kernel.org/r/20170105151737.GU21618@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

mm: trace-vmscan-postprocess.pl: report the number of file/anon pages respectively

Until now, the reporting from trace-vmscan-postprocess.pl is not very
useful because we cannot directly

mm: trace-vmscan-postprocess.pl: report the number of file/anon pages respectively

Until now, the reporting from trace-vmscan-postprocess.pl is not very
useful because we cannot directly use this script for checking the
file/anon ratio of scanning. This patch aims to report respectively the
number of file/anon pages which were scanned/reclaimed by kswapd or
direct-reclaim. Sample output is usually something like the following.

Summary
Direct reclaims: 8823
Direct reclaim pages scanned: 2438797
Direct reclaim file pages scanned: 1315200
Direct reclaim anon pages scanned: 1123597
Direct reclaim pages reclaimed: 446139
Direct reclaim file pages reclaimed: 378668
Direct reclaim anon pages reclaimed: 67471
Direct reclaim write file sync I/O: 0
Direct reclaim write anon sync I/O: 0
Direct reclaim write file async I/O: 0
Direct reclaim write anon async I/O: 4240
Wake kswapd requests: 122310
Time stalled direct reclaim: 13.78 seconds

Kswapd wakeups: 25817
Kswapd pages scanned: 170779115
Kswapd file pages scanned: 162725123
Kswapd anon pages scanned: 8053992
Kswapd pages reclaimed: 129065738
Kswapd file pages reclaimed: 128500930
Kswapd anon pages reclaimed: 564808
Kswapd reclaim write file sync I/O: 0
Kswapd reclaim write anon sync I/O: 0
Kswapd reclaim write file async I/O: 36
Kswapd reclaim write anon async I/O: 730730
Time kswapd awake: 1015.50 seconds

Signed-off-by: Chen Yucong <slaoub@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

mm:vmscan: update the trace-vmscan-postprocess.pl for event vmscan/mm_vmscan_lru_isolate

When using trace-vmscan-postprocess.pl for checking the file/anon rate
of scanning, we can find t

mm:vmscan: update the trace-vmscan-postprocess.pl for event vmscan/mm_vmscan_lru_isolate

When using trace-vmscan-postprocess.pl for checking the file/anon rate
of scanning, we can find that it can not be performed. At the same
time, the following message will be reported:

WARNING: Format not as expected for event vmscan/mm_vmscan_lru_isolate
'file' != 'contig_taken' Fewer fields than expected in format at
./trace-vmscan-postprocess.pl line 171, <FORMAT> line 76.

In trace-vmscan-postprocess.pl, (contig_taken, contig_dirty, and
contig_failed) are be associated respectively to (nr_lumpy_taken,
nr_lumpy_dirty, and nr_lumpy_failed) for lumpy reclaim. Via commit
c53919adc045 ("mm: vmscan: remove lumpy reclaim"), lumpy reclaim had
already been removed by Mel, but the update for
trace-vmscan-postprocess.pl was missed.

Signed-off-by: Chen Yucong <slaoub@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

Documentation/trace/postprocess/trace-vmscan-postprocess.pl: fix the traceevent regex

When irq, preempt and lockdep fields are printed (field 3 in the example
below) in the trace output,

Documentation/trace/postprocess/trace-vmscan-postprocess.pl: fix the traceevent regex

When irq, preempt and lockdep fields are printed (field 3 in the example
below) in the trace output, the script fails.

An example entry:
kswapd0-610 [000] ...1 158.112152: mm_vmscan_kswapd_wake: nid=0 order=0

Signed-off-by: Vinayak Menon <vinayakm.list@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

mm: change isolate mode from #define to bitwise type

Change ISOLATE_XXX macro with bitwise isolate_mode_t type. Normally,
macro isn't recommended as it's type-unsafe and making debuggin

mm: change isolate mode from #define to bitwise type

Change ISOLATE_XXX macro with bitwise isolate_mode_t type. Normally,
macro isn't recommended as it's type-unsafe and making debugging harder as
symbol cannot be passed throught to the debugger.

Quote from Johannes
" Hmm, it would probably be cleaner to fully convert the isolation mode
into independent flags. INACTIVE, ACTIVE, BOTH is currently a
tri-state among flags, which is a bit ugly."

This patch moves isolate mode from swap.h to mmzone.h by memcontrol.h

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

mm: vmscan: tracepoint: account for scanned pages similarly for both ftrace and vmstat

When correlating ftrace results with /proc/vmstat, I noticed that the
reporting scripts value for "

mm: vmscan: tracepoint: account for scanned pages similarly for both ftrace and vmstat

When correlating ftrace results with /proc/vmstat, I noticed that the
reporting scripts value for "pages scanned" differed significantly. Both
values were "right" depending on how you look at it.

The difference is due to vmstat only counting scanning of the inactive
list towards pages scanned. The analysis script for the tracepoint counts
active and inactive list yielding a far higher value than vmstat. The
resulting scanning/reclaim ratio looks much worse. The tracepoint is ok
but this patch updates the reporting script so that the report values for
scanned are similar to vmstat.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

tracing, vmscan: add trace events for LRU list shrinking

There have been numerous reports of stalls that pointed at the problem
being somewhere in the VM. There are multiple roots to th

tracing, vmscan: add trace events for LRU list shrinking

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 were

X86: Intel P4 2-core
X86-64: AMD Phenom 4-core
PPC64: PPC970MP

Each 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-rc4

traceonly-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 congested

nocongest-v1r5: Patches 1-3 for testing wait_iff_congestion
nodirect-v1r5: Patches 1-10 to disable filesystem writeback for better IO

The tests run were as follows

kernbench
compile-based benchmark. Smoke test performance

sysbench
OLTP read-only benchmark. Will be re-run in the future as read-write

micro-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 10.19

Total 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 0

The 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 12.76

Overall, 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 23.90

Total 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 0

The 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 30.88

With 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 1176.82

Total 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.ps

FTrace 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 9

Overall, 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 3765.39

With 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 1328.88

Total 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 0

Not 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 3229.85

The 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 <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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

vmscan: tracing: add a postprocessing script for reclaim-related ftrace events

Add a simple post-processing script for the reclaim-related trace events.
It can be used to give an indicat

vmscan: tracing: add a postprocessing script for reclaim-related ftrace events

Add a simple post-processing script for the reclaim-related trace events.
It can be used to give an indication of how much traffic there is on the
LRU lists and how severe latencies due to reclaim are. Example output
looks like the following

Reclaim latencies expressed as order-latency_in_ms
uname-3942 9-200.179000000004 9-98.7900000000373 9-99.8330000001006
kswapd0-311 0-662.097999999998 0-2.79700000002049 \
0-149.100000000035 0-3295.73600000003 0-9806.31799999997 0-35528.833 \
0-10043.197 0-129740.979 0-3.50500000000466 0-3.54899999999907 \
0-9297.78999999992 0-3.48499999998603 0-3596.97999999998 0-3.92799999995623 \
0-3.35000000009313 0-16729.017 0-3.57799999997951 0-47435.0630000001 \
0-3.7819999998901 0-5864.06999999995 0-18635.334 0-10541.289 9-186011.565 \
9-3680.86300000001 9-1379.06499999994 9-958571.115 9-66215.474 \
9-6721.14699999988 9-1962.15299999993 9-1094806.125 9-2267.83199999994 \
9-47120.9029999999 9-427653.886 9-2.6359999999404 9-632.148999999976 \
9-476.753000000026 9-495.577000000048 9-8.45900000003166 9-6.6820000000298 \
9-1.30500000016764 9-251.746000000043 9-383.905000000028 9-80.1419999999925 \
9-281.160000000149 9-14.8780000000261 9-381.45299999998 9-512.07799999998 \
9-49.5519999999087 9-167.439000000013 9-183.820999999996 9-239.527999999933 \
9-19.9479999998584 9-148.747999999905 9-164.583000000101 9-16.9480000000913 \
9-192.376000000164 9-64.1010000000242 9-1.40800000005402 9-3.60800000000745 \
9-17.1359999999404 9-4.69500000006519 9-2.06400000001304 9-1582488.554 \
9-6244.19499999983 9-348153.812 9-2.0999999998603 9-0.987999999895692 \
0-32218.473 0-1.6140000000596 0-1.28100000019185 0-1.41300000017509 \
0-1.32299999985844 0-602.584000000032 0-1.34400000004098 0-1.6929999999702 \
1-22101.8190000001 9-174876.724 9-16.2420000000857 9-175.165999999736 \
9-15.8589999997057 9-0.604999999981374 9-3061.09000000032 9-479.277000000235 \
9-1.54499999992549 9-771.985000000335 9-4.88700000010431 9-15.0649999999441 \
9-0.879999999888241 9-252.01500000013 9-1381.03600000031 9-545.689999999944 \
9-3438.0129999998 9-3343.70099999988
bench-stresshig-3942 9-7063.33900000004 9-129960.482 9-2062.27500000002 \
9-3845.59399999992 9-171.82799999998 9-16493.821 9-7615.23900000006 \
9-10217.848 9-983.138000000035 9-2698.39999999991 9-4016.1540000001 \
9-5522.37700000009 9-21630.429 \
9-15061.048 9-10327.953 9-542.69700000016 9-317.652000000002 \
9-8554.71699999995 9-1786.61599999992 9-1899.31499999994 9-2093.41899999999 \
9-4992.62400000007 9-942.648999999976 9-1923.98300000001 9-3.7980000001844 \
9-5.99899999983609 9-0.912000000011176 9-1603.67700000014 9-1.98300000000745 \
9-3.96500000008382 9-0.902999999932945 9-2802.72199999983 9-1078.24799999991 \
9-2155.82900000014 9-10.058999999892 9-1984.723 9-1687.97999999998 \
9-1136.05300000007 9-3183.61699999985 9-458.731000000145 9-6.48600000003353 \
9-1013.25200000009 9-8415.22799999989 9-10065.584 9-2076.79600000009 \
9-3792.65699999989 9-71.2010000001173 9-2560.96999999997 9-2260.68400000012 \
9-2862.65799999982 9-1255.81500000018 9-15.7440000001807 9-4.33499999996275 \
9-1446.63800000004 9-238.635000000009 9-60.1790000000037 9-4.38800000003539 \
9-639.567000000039 9-306.698000000091 9-31.4070000001229 9-74.997999999905 \
9-632.725999999791 9-1625.93200000003 9-931.266000000061 9-98.7749999999069 \
9-984.606999999844 9-225.638999999966 9-421.316000000108 9-653.744999999879 \
9-572.804000000004 9-769.158999999985 9-603.918000000063 9-4.28499999991618 \
9-626.21399999992 9-1721.25 9-0.854999999981374 9-572.39599999995 \
9-681.881999999983 9-1345.12599999993 9-363.666999999899 9-3823.31099999999 \
9-2991.28200000012 9-4.27099999994971 9-309.76500000013 9-3068.35700000008 \
9-788.25 9-3515.73999999999 9-2065.96100000013 9-286.719999999972 \
9-316.076000000117 9-344.151000000071 9-2.51000000000931 9-306.688000000082 \
9-1515.00099999993 9-336.528999999864 9-793.491999999853 9-457.348999999929 \
9-13620.155 9-119.933999999892 9-35.0670000000391 9-918.266999999993 \
9-828.569000000134 9-4863.81099999999 9-105.222000000067 9-894.23900000006 \
9-110.964999999851 9-0.662999999942258 9-12753.3150000002 9-12.6129999998957 \
9-13368.0899999999 9-12.4199999999255 9-1.00300000002608 9-1.41100000008009 \
9-10300.5290000001 9-16.502000000095 9-30.7949999999255 9-6283.0140000002 \
9-4320.53799999994 9-6826.27300000004 9-3.07299999985844 9-1497.26799999992 \
9-13.4040000000969 9-3.12999999988824 9-3.86100000003353 9-11.3539999998175 \
9-0.10799999977462 9-21.780999999959 9-209.695999999996 9-299.647000000114 \
9-6.01699999999255 9-20.8349999999627 9-22.5470000000205 9-5470.16800000006 \
9-7.60499999998137 9-0.821000000229105 9-1.56600000010803 9-14.1669999998994 \
9-0.209000000031665 9-1.82300000009127 9-1.70000000018626 9-19.9429999999702 \
9-124.266999999993 9-0.0389999998733401 9-6.71400000015274 9-16.7710000001825 \
9-31.0409999999683 9-0.516999999992549 9-115.888000000035 9-5.19900000002235 \
9-222.389999999898 9-11.2739999999758 9-80.9050000000279 9-8.14500000001863 \
9-4.44599999999627 9-0.218999999808148 9-0.715000000083819 9-0.233000000007451
\
9-48.2630000000354 9-248.560999999987 9-374.96800000011 9-644.179000000004 \
9-0.835999999893829 9-79.0060000000522 9-128.447999999858 9-0.692000000039116 \
9-5.26500000013039 9-128.449000000022 9-2.04799999995157 9-12.0990000001621 \
9-8.39899999997579 9-10.3860000001732 9-11.9310000000987 9-53.4450000000652 \
9-0.46999999997206 9-2.96299999998882 9-17.9699999999721 9-0.776000000070781 \
9-25.2919999998994 9-33.1110000000335 9-0.434000000124797 9-0.641000000061467 \
9-0.505000000121072 9-1.12800000002608 9-149.222000000067 9-1.17599999997765 \
9-3247.33100000001 9-10.7439999999478 9-153.523000000045 9-1.38300000014715 \
9-794.762000000104 9-3.36199999996461 9-128.765999999829 9-181.543999999994 \
9-78149.8229999999 9-176.496999999974 9-89.9940000001807 9-9.12700000009499 \
9-250.827000000048 9-0.224999999860302 9-0.388999999966472 9-1.16700000036508 \
9-32.1740000001155 9-12.6800000001676 9-0.0720000001601875 9-0.274999999906868
\
9-0.724000000394881 9-266.866000000387 9-45.5709999999963 9-4.54399999976158 \
9-8.27199999988079 9-4.38099999958649 9-0.512000000104308 9-0.0640000002458692
\
9-5.20000000018626 9-0.0839999997988343 9-12.816000000108 9-0.503000000026077 \
9-0.507999999914318 9-6.23999999975786 9-3.35100000025705 9-18.8530000001192 \
9-25.2220000000671 9-68.2309999996796 9-98.9939999999478 9-0.441000000108033 \
9-4.24599999981001 9-261.702000000048 9-3.01599999982864 9-0.0749999997206032 \
9-0.0370000000111759 9-4.375 9-3.21800000034273 9-11.3960000001825 \
9-0.0540000000037253 9-0.286000000312924 9-0.865999999921769 \
9-0.294999999925494 9-6.45999999996275 9-4.31099999975413 9-128.248999999836 \
9-0.282999999821186 9-102.155000000261 9-0.0860000001266599 \
9-0.0540000000037253 9-0.935000000055879 9-0.0670000002719462 \
9-5.8640000000596 9-19.9860000000335 9-4.18699999991804 9-0.566000000108033 \
9-2.55099999997765 9-0.702000000048429 9-131.653999999631 9-0.638999999966472 \
9-14.3229999998584 9-183.398000000045 9-178.095999999903 9-3.22899999981746 \
9-7.31399999978021 9-22.2400000002235 9-11.7979999999516 9-108.10599999968 \
9-99.0159999998286 9-102.640999999829 9-38.414000000339
Process Direct Wokeup Pages Pages Pages
details Rclms Kswapd Scanned Sync-IO ASync-IO
cc1-30800 0 1 0 0 0 wakeup-0=1
cc1-24260 0 1 0 0 0 wakeup-0=1
cc1-24152 0 12 0 0 0 wakeup-0=12
cc1-8139 0 1 0 0 0 wakeup-0=1
cc1-4390 0 1 0 0 0 wakeup-0=1
cc1-4648 0 7 0 0 0 wakeup-0=7
cc1-4552 0 3 0 0 0 wakeup-0=3
dd-4550 0 31 0 0 0 wakeup-0=31
date-4898 0 1 0 0 0 wakeup-0=1
cc1-6549 0 7 0 0 0 wakeup-0=7
as-22202 0 17 0 0 0 wakeup-0=17
cc1-6495 0 9 0 0 0 wakeup-0=9
cc1-8299 0 1 0 0 0 wakeup-0=1
cc1-6009 0 1 0 0 0 wakeup-0=1
cc1-2574 0 2 0 0 0 wakeup-0=2
cc1-30568 0 1 0 0 0 wakeup-0=1
cc1-2679 0 6 0 0 0 wakeup-0=6
sh-13747 0 12 0 0 0 wakeup-0=12
cc1-22193 0 18 0 0 0 wakeup-0=18
cc1-30725 0 2 0 0 0 wakeup-0=2
as-4392 0 2 0 0 0 wakeup-0=2
cc1-28180 0 14 0 0 0 wakeup-0=14
cc1-13697 0 2 0 0 0 wakeup-0=2
cc1-22207 0 8 0 0 0 wakeup-0=8
cc1-15270 0 179 0 0 0 wakeup-0=179
cc1-22011 0 82 0 0 0 wakeup-0=82
cp-14682 0 1 0 0 0 wakeup-0=1
as-11926 0 2 0 0 0 wakeup-0=2
cc1-6016 0 5 0 0 0 wakeup-0=5
make-18554 0 13 0 0 0 wakeup-0=13
cc1-8292 0 12 0 0 0 wakeup-0=12
make-24381 0 1 0 0 0 wakeup-1=1
date-18681 0 33 0 0 0 wakeup-0=33
cc1-32276 0 1 0 0 0 wakeup-0=1
timestamp-outpu-2809 0 253 0 0 0 wakeup-0=240 wakeup-1=13
date-18624 0 7 0 0 0 wakeup-0=7
cc1-30960 0 9 0 0 0 wakeup-0=9
cc1-4014 0 1 0 0 0 wakeup-0=1
cc1-30706 0 22 0 0 0 wakeup-0=22
uname-3942 4 1 306 0 17 direct-9=4 wakeup-9=1
cc1-28207 0 1 0 0 0 wakeup-0=1
cc1-30563 0 9 0 0 0 wakeup-0=9
cc1-22214 0 10 0 0 0 wakeup-0=10
cc1-28221 0 11 0 0 0 wakeup-0=11
cc1-28123 0 6 0 0 0 wakeup-0=6
kswapd0-311 0 7 357302 0 34233 wakeup-0=7
cc1-5988 0 7 0 0 0 wakeup-0=7
as-30734 0 161 0 0 0 wakeup-0=161
cc1-22004 0 45 0 0 0 wakeup-0=45
date-4590 0 4 0 0 0 wakeup-0=4
cc1-15279 0 213 0 0 0 wakeup-0=213
date-30735 0 1 0 0 0 wakeup-0=1
cc1-30583 0 4 0 0 0 wakeup-0=4
cc1-32324 0 2 0 0 0 wakeup-0=2
cc1-23933 0 3 0 0 0 wakeup-0=3
cc1-22001 0 36 0 0 0 wakeup-0=36
bench-stresshig-3942 287 287 80186 6295 12196 direct-9=287 wakeup-9=287
cc1-28170 0 7 0 0 0 wakeup-0=7
date-7932 0 92 0 0 0 wakeup-0=92
cc1-22222 0 6 0 0 0 wakeup-0=6
cc1-32334 0 16 0 0 0 wakeup-0=16
cc1-2690 0 6 0 0 0 wakeup-0=6
cc1-30733 0 9 0 0 0 wakeup-0=9
cc1-32298 0 2 0 0 0 wakeup-0=2
cc1-13743 0 18 0 0 0 wakeup-0=18
cc1-22186 0 4 0 0 0 wakeup-0=4
cc1-28214 0 11 0 0 0 wakeup-0=11
cc1-13735 0 1 0 0 0 wakeup-0=1
updatedb-8173 0 18 0 0 0 wakeup-0=18
cc1-13750 0 3 0 0 0 wakeup-0=3
cat-2808 0 2 0 0 0 wakeup-0=2
cc1-15277 0 169 0 0 0 wakeup-0=169
date-18317 0 1 0 0 0 wakeup-0=1
cc1-15274 0 197 0 0 0 wakeup-0=197
cc1-30732 0 1 0 0 0 wakeup-0=1

Kswapd Kswapd Order Pages Pages Pages
Instance Wakeups Re-wakeup Scanned Sync-IO ASync-IO
kswapd0-311 91 24 357302 0 34233 wake-0=31 wake-1=1 wake-9=59 rewake-0=10 rewake-1=1 rewake-9=13

Summary
Direct reclaims: 291
Direct reclaim pages scanned: 437794
Direct reclaim write sync I/O: 6295
Direct reclaim write async I/O: 46446
Wake kswapd requests: 2152
Time stalled direct reclaim: 519.163009000002 ms

Kswapd wakeups: 91
Kswapd pages scanned: 357302
Kswapd reclaim write sync I/O: 0
Kswapd reclaim write async I/O: 34233
Time kswapd awake: 5282.749757 ms

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Larry Woodman <lwoodman@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michael Rubin <mrubin@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...