[Dle-develop] [PATCH 0/4] delayacct: save max CPU/IO/SWAP/RECLAIM delays

[Satoru M. <sat...@hd...>]

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