lkml.org 
[lkml]   [2009]   [Jun]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: register_timer_hook use in arch/sh/oprofile
From
Date
On Fri, 2009-06-26 at 09:23 +0200, Ingo Molnar wrote:
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > On Wed, 2009-06-24 at 15:24 +0200, Ingo Molnar wrote:
> > >
> > > [ And long-term analysis ('perf stat' type of runs) dont need IRQs
> > > anyway - perfcounters reads outs the counts and summarizes them
> > > across the measured workload. ]
> >
> > If the counter width is less than 64 bits we do need to have some
> > interrupt to read them from before they cycle so we can accumulate
> > the deltas into a proper u64.
>
> Yeah - but even that can be driven from some housekeeping hrtimer.

Oh absolutely, but its one of those things one should not forget to do.

> > But for proper 64 bit hardware counters there is indeed no need
> > for that.
>
> Indeed - although they are rare.

Paul Mundt mentioned he had some.


\
 
 \ /
  Last update: 2009-06-26 09:39    [W:0.091 / U:0.196 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site