2009-11-13 18:58:08

by Larry Woodman

[permalink] [raw]
Subject: [PATCH] mm page reclaim tracepoints update

I've broken the mm tracepoint up into functional and more useful groups.
This group consists of page reclamation tracepoints, all within vmscan.c
In addition, I moved to TRACE_EVENT definitions in
include/trace/events/kmem.h like the other mm tracepoints rather than
creating a new header file.

1.) mm_kswapd_ran: This tracepoint records how many pages were
reclaimed from kswapd on a per node basis.

# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
<...>-626 [005] 142.943401: mm_kswapd_ran: node=1
reclaimed=1273
<...>-626 [005] 143.159882: mm_kswapd_ran: node=1
reclaimed=2473
<...>-626 [005] 143.226377: mm_kswapd_ran: node=1
reclaimed=4675
<...>-626 [005] 143.473898: mm_kswapd_ran: node=1
reclaimed=24056
<...>-625 [000] 151.428285: mm_kswapd_ran: node=0
reclaimed=55816


2.) mm_pagereclaim_reclaimall: This tracepoint records how many pages
were reclaimed due to direct reclaim occurring out of the memory
allocator, on each node and the priority achieved.

# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
memory-9974 [000] 213.795877: mm_directreclaim_reclaimall:
node=0 reclaimed=42 priority=11
memory-9974 [004] 214.134956: mm_directreclaim_reclaimall:
node=1 reclaimed=52 priority=10
memory-9974 [007] 214.407464: mm_directreclaim_reclaimall:
node=1 reclaimed=96 priority=10
memory-9974 [001] 214.577797: mm_directreclaim_reclaimall:
node=0 reclaimed=128 priority=8
memory-9974 [004] 215.022107: mm_directreclaim_reclaimall:
node=1 reclaimed=64 priority=10


3.) mm_direct_reclaim_reclaimzone: This tracepoint records how many
pages were reclaimed when a numa node was exhausted but other nodes were
not because zone_reclaim_mode was set during boot.


4.) mm_pagereclaim_shrink_zone: This tracepoint records how many pages
were reclaimed by a single invocation of shrink_zone and the priority.

# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
kswapd1-626 [005] 223.090040: mm_pagereclaim_shrinkzone:
reclaimed=63 priority=10
kswapd0-625 [002] 223.271915: mm_pagereclaim_shrinkzone:
reclaimed=224 priority=10
memory-9980 [004] 223.465403: mm_pagereclaim_shrinkzone:
reclaimed=50 priority=10
restorecond-9028 [001] 223.465776: mm_pagereclaim_shrinkzone:
reclaimed=49 priority=10
memory-9980 [004] 223.469705: mm_pagereclaim_shrinkzone:
reclaimed=93 priority=10


5.) mm_pagereclaim_shrinkactive: This tracepoint records how many pages
were deactivated and reactivated by a single invocation of
shrink_active_list, whether they were anonymous or pagecache pages and
the priority.

# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
kswapd0-625 [000] 141.697105: mm_pagereclaim_shrinkactive:
scanned=32, anonymous, priority=12
kswapd1-626 [004] 141.917568: mm_pagereclaim_shrinkactive:
scanned=32, anonymous, priority=12
restorecond-9031 [003] 144.262264: mm_pagereclaim_shrinkactive:
scanned=32, anonymous, priority=12
memory-9978 [004] 144.301358: mm_pagereclaim_shrinkactive:
scanned=32, anonymous, priority=12
Xorg-9711 [002] 147.927108: mm_pagereclaim_shrinkactive:
scanned=32, pagecache, priority=7


6.) mm_pagereclaim_shrinkinactive: This tracepoint records how many
pages were reclaimed and freed by a single invocation of
shrink_inactive_list, the total number of inactive pages scanned and the
priority.

# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
kswapd1-626 [005] 124.740577:
mm_pagereclaim_shrinkinactive: scanned=32, reclaimed=31, priority=10
memory-9975 [000] 126.175589:
mm_pagereclaim_shrinkinactive: scanned=32, reclaimed=32, priority=11
kswapd0-625 [002] 128.949227:
mm_pagereclaim_shrinkinactive: scanned=32, reclaimed=32, priority=11
memory-9975 [004] 129.547320:
mm_pagereclaim_shrinkinactive: scanned=32, reclaimed=32, priority=11
restorecond-9030 [001] 129.550783:
mm_pagereclaim_shrinkinactive: scanned=32, reclaimed=32, priority=11
~


When these tracepoints are enabled together its easy and useful to
determine exactly what is being done on the page reclaim logic. You can
clearly see how many pages are reclaimed by kswapd and direct reclaim,
how the priority is decreasing with each call to shrink_zone and how
effective shrink_active_list and shrink_inactive_list are in reclaiming
memory:

# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
kswapd0-625 [000] 221.037254: mm_pagereclaim_shrinkactive:
scanned=32, anonymous, priority=10
kswapd0-625 [000] 221.037270: mm_pagereclaim_shrinkactive:
scanned=32, anonymous, priority=10
kswapd0-625 [000] 221.037286:
mm_pagereclaim_shrinkinactive: scanned=32, reclaimed=32, priority=10
kswapd0-625 [000] 221.037302:
mm_pagereclaim_shrinkinactive: scanned=32, reclaimed=32, priority=10
kswapd0-625 [000] 221.037302: mm_pagereclaim_shrinkzone:
reclaimed=64 priority=10
kswapd0-625 [000] 221.037386: mm_kswapd_ran: node=0
reclaimed=408

memory-9973 [006] 221.052384: mm_pagereclaim_shrinkactive:
scanned=32, anonymous, priority=9
memory-9973 [006] 221.052399: mm_pagereclaim_shrinkactive:
scanned=32, anonymous, priority=9
memory-9973 [006] 221.052456:
mm_pagereclaim_shrinkinactive: scanned=32, reclaimed=28, priority=9
memory-9973 [006] 221.052507:
mm_pagereclaim_shrinkinactive: scanned=32, reclaimed=32, priority=9
memory-9973 [006] 221.052507: mm_pagereclaim_shrinkzone:
reclaimed=60 priority=9
memory-9973 [006] 221.052553: mm_directreclaim_reclaimall:
node=1 reclaimed=60 priority=9


Signed-off-by: Larry Woodman <[email protected]>


Attachments:
upstream.diff (8.12 kB)