lkml.org 
[lkml]   [2009]   [Jan]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [GIT PULL] adaptive spinning mutexes

* Andrew Morton <akpm@linux-foundation.org> wrote:

> On Wed, 14 Jan 2009 19:33:19 +0100 Ingo Molnar <mingo@elte.hu> wrote:
>
> > Please pull the adaptive-mutexes-for-linus git tree
>
> <fear>
>
> - It seems a major shortcoming that the feature is disabled if
> CONFIG_DEBUG_MUTEXES=y. It means that lots of people won't test it.
>
> - When people hit performance/latency oddities, it would be nice if
> they had a /proc knob with which they could disable this feature at
> runtime.
>
> This would also be useful for comparative performance testing.

Yeah. From my other mail:

> > We still have the /sys/debug/sched_features tunable under
> > CONFIG_SCHED_DEBUG=y, so should this cause any performance regressions
> > somewhere, it can be pinned down and blamed back on this change
> > easily, without bisection and without rebooting the box.

This kind of easy knob was included early on - this is how all those spin
versus no-spin numbers were done.

Ingo


\
 
 \ /
  Last update: 2009-01-14 20:03    [W:0.170 / U:3.848 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site