In the latency sensitive systems, we usually focus on the worst latency.
And so, it is useful to save max delays into the per-task delay
accounting functionality.
Example output:
(on 100 concurrent dd reading sparse files w/ 1 dd writing a file)
CPU count real total virtual total delay total delay_max delay average
222 45993008 74603882 7637295 3691858 0.034ms
IO count delay total delay max delay average
2 21812073 12728672 10ms
SWAP count delay total delay max delay average
0 0 0 0ms
RECLAIM count delay total delay_max delay average
2 348488 211985 0ms
Any comments are welcome.
Satoru Moriya (4):
sched: add members to struct sched_info to save maximum
delayacct: add members to struct task_delay_info to save max delays
delayacct: update taskstats to save max delays
getdelays: show max CPU/IO/SWAP/RECLAIM delays
Documentation/accounting/getdelays.c | 28 ++++++++++++++----------
Documentation/accounting/taskstats-struct.txt | 9 ++++++++
include/linux/sched.h | 5 ++++
include/linux/taskstats.h | 8 ++++++-
kernel/delayacct.c | 25 +++++++++++++++++----
kernel/sched_stats.h | 5 ++++
6 files changed, 62 insertions(+), 18 deletions(-)
--
1.7.6.4
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