lkml.org 
[lkml]   [2006]   [Jun]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH RFC] smt nice introduces significant lock contention
Date
On Friday 02 June 2006 19:31, Chen, Kenneth W wrote:
> Con Kolivas wrote on Friday, June 02, 2006 2:25 AM
>
> > On Friday 02 June 2006 19:17, Chen, Kenneth W wrote:
> > > What about the part in dependent_sleeper() being so bully and actively
> > > resched other low priority sibling tasks? I think it would be better
> > > to just let the tasks running on sibling CPU to finish its current time
> > > slice and then let the backoff logic to kick in.
> >
> > That would defeat the purpose of smt nice if the higher priority task
> > starts after the lower priority task is running on its sibling cpu.
>
> But only for the duration of lower priority tasks' time slice. When lower
> priority tasks time slice is used up, a resched is force from
> scheduler_tick(), isn't it? And at that time, it is delayed to run because
> of smt_nice. You are saying user can't tolerate that short period of time
> that CPU resource is shared? It's hard to believe.

nice -20 vs nice 0 is 800ms vs 100ms. That's a long time to me.

--
-ck
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-06-02 11:37    [W:0.324 / U:0.532 seconds]
©2003-2014 Jasper Spaans. Advertise on this site