Re: [PATCH 0/4] delayacct: save max CPU/IO/SWAP/RECLAIM delays

[Peter Zijlstra <peterz@infradead.org>]

On Mon, 2011-11-28 at 17:44 -0500, Satoru Moriya wrote:
> 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.

No!!!

Linus told us to be bastards, so there you have it.

There's way too many different accounting crap thingies around. And now
I get a patch without any justification what so ever. So no, piss off.