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| author | Mike Galbraith <efault@gmx.de> | 2009-10-10 14:46:04 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-10-12 09:10:55 +0200 |
| commit | 55ffb7a6bd45d0083ffb132381cb46964a4afe01 (patch) | |
| tree | 89853e721eda384aad61bf71960bfdaea92269f5 /block/blk-sysfs.c | |
| parent | 7e4ff9e3e8f88de8a8536f43294cd32b4e7d9123 (diff) | |
perf sched: Add -C option to measure on a specific CPU
To refresh, trying to sched record only one CPU results in bogus
latencies as below.
I fixed^Wmade it stop doing the bad thing today, by
following task migration events properly.
Before:
marge:/root/tmp # taskset -c 1 perf sched record -C 0 -- sleep 10
marge:/root/tmp # perf sched lat
-----------------------------------------------------------------------------------------
Task | Runtime ms | Switches | Average delay ms | Maximum delay ms |
-----------------------------------------------------------------------------------------
Xorg:4943 | 1.290 ms | 1 | avg: 1670.132 ms | max: 1670.132 ms |
hald-addon-stor:3569 | 0.091 ms | 3 | avg: 658.609 ms | max: 1975.797 ms |
hald-addon-stor:3573 | 0.209 ms | 4 | avg: 499.138 ms | max: 1990.565 ms |
audispd:4270 | 0.012 ms | 1 | avg: 0.015 ms | max: 0.015 ms |
....
marge:/root/tmp # perf sched trace|grep 'Xorg:4943'
swapper-0 [000] 401.184013288: sched_stat_runtime: task: Xorg:4943 runtime: 1233188 [ns], vruntime: 19105169779 [ns]
rt2870TimerQHan-4947 [000] 402.854140127: sched_stat_wait: task: Xorg:4943 wait: 580073 [ns]
rt2870TimerQHan-4947 [000] 402.854141770: sched_migrate_task: task Xorg:4943 [140] from: 1 to: 0
rt2870TimerQHan-4947 [000] 402.854143854: sched_stat_wait: task: Xorg:4943 wait: 0 [ns]
rt2870TimerQHan-4947 [000] 402.854145397: sched_switch: task rt2870TimerQHan:4947 [140] (D) ==> Xorg:4943 [140]
Xorg-4943 [000] 402.854193133: sched_stat_runtime: task: Xorg:4943 runtime: 56546 [ns], vruntime: 11766332500 [ns]
Xorg-4943 [000] 402.854196842: sched_switch: task Xorg:4943 [140] (S) ==> swapper:0 [140]
After:
marge:/root/tmp # taskset -c 1 perf sched record -C 0 -- sleep 10
marge:/root/tmp # perf sched lat
-----------------------------------------------------------------------------------------
Task | Runtime ms | Switches | Average delay ms | Maximum delay ms |
-----------------------------------------------------------------------------------------
amarokapp:11150 | 271.297 ms | 878 | avg: 0.130 ms | max: 1.057 ms |
konsole:5965 | 1.370 ms | 12 | avg: 0.092 ms | max: 0.855 ms |
Xorg:4943 | 179.980 ms | 1109 | avg: 0.087 ms | max: 1.206 ms |
hald-addon-stor:3574 | 0.212 ms | 9 | avg: 0.040 ms | max: 0.169 ms |
hald-addon-stor:3570 | 0.223 ms | 9 | avg: 0.037 ms | max: 0.223 ms |
klauncher:5864 | 0.550 ms | 8 | avg: 0.032 ms | max: 0.048 ms |
The 'Maximum delay ms' results are now sane.
Signed-off-by: Mike Galbraith <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'block/blk-sysfs.c')
0 files changed, 0 insertions, 0 deletions