Re: delayacct regression in 2.6.24 git

From: Ingo Molnar
Date: Fri Nov 02 2007 - 11:25:51 EST



* Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:

> Hi, Ingo,
>
> I missed commit 75d4ef16a6aa84f708188bada182315f80aab6fa
> "sched: fix delay accounting performance regression"
>
> Without these changes, I find that delay accounting does
> not work as expected, I see zeros in the field for virtual,delay
> and count(s).
>
> CPU count real total virtual total delay total
> 0 535861848 0 0
>
>
> This breaks existing delay accounting behaviour.
>
> Am I missing something?

delay accounting was causing context-switch slowdown because it called
sched_clock() explicitly - but indeed my fix to that is wrong ...

how about reverting the change but also using rq->clock instead of
sched_clock()?

Ingo
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