Re: [rfc patch] Re: sched: incorrect argument used in task_hot()

[Andrew Morton <akpm@osdl.org>]

On Fri, 17 Nov 2006 22:30:34 +0100
Mike Galbraith <efault@gmx.de> wrote:

> On Fri, 2006-11-17 at 20:20 +0100, Ingo Molnar wrote:
> > * Mike Galbraith <efault@gmx.de> wrote:
> > 
> > > One way to improve granularity, and eliminate the possibility of 
> > > p->last_run being > rq->timestamp_tast_tick, and thereby short 
> > > circuiting the evaluation of cache_hot_time, is to cache the last 
> > > return of sched_clock() at both tick and sched times, and use that 
> > > value as our reference instead of the absolute time of the tick.  It 
> > > won't totally eliminate skew, but it moves the reference point closer 
> > > to the current time on the remote cpu.
> > > 
> > > Looking for a good place to do this, I chose update_cpu_clock().
> > 
> > looks good to me - thus we will update the timestamp not only in the 
> > timer tick, but also upon every context-switch (when we acquire 
> > sched_clock() value anyway). Lets try this in -mm?
> > 
> > Acked-by: Ingo Molnar <mingo@elte.hu>
> 
> Then it needs a blame line.
> 
> Signed-off-by: Mike Galbraith <efault@gmx.de>
>

And a changelog, then we're all set!

Oh.  And a patch, too.