Re: Poor performance now? Please, put weighted velocities ctxts/s to the sched.decision!

From: Ray Lee
Date: Tue Mar 25 2008 - 16:39:15 EST


On Tue, Mar 25, 2008 at 1:29 PM, J.C. Pizarro <jcpiza@xxxxxxxxx> wrote:
> [2] "Re: Serious performance regression in Wine applications and Linux 2.6.24.*"
> http://lkml.org/lkml/2008/3/25/181
> On Tue, 25 Mar 2008 08:49:13 -0700, "Ray Lee" wrote:
> > Andi's idea of looking for excessive context switches is good -- I
> > didn't see a response to that one. Other than that, if you're only
> > noticing the issue in 3d games, then it could be several things (not
> > just the scheduler).
>
> The kernel needed the velocity parameter to gain it: ctxts per interval
> (normally ctxts/s or ctxts/minute).

We don't know that's the problem yet. The reporter is doing more testing.

> "Please, put 64-bit counter per task and incr.by.one each ctxt switch."
> http://lkml.org/lkml/2008/2/23/398
> http://lkml.org/lkml/2008/2/23/401
> http://lkml.org/lkml/2008/2/23/406
> http://lkml.org/lkml/2008/2/24/1
> http://lkml.org/lkml/2008/2/24/103
> http://lkml.org/lkml/2008/2/24/157
> http://lkml.org/lkml/2008/2/26/159

There are already counters recording the switches:
http://lkml.org/lkml/2008/2/25/314

> My proposal is free for yours, quasi-bastards, I won't charge you!

My parents were married.
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