lkml.org 
[lkml]   [2009]   [Apr]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] tracing/filters: allow event filters to be set only when not tracing
On Fri, Apr 03, 2009 at 12:43:15PM -0400, Steven Rostedt wrote:
>
> On Fri, 3 Apr 2009, Ingo Molnar wrote:
> > >
> > > My kneejerk reaction is "why would anyone want to trace the idle
> > > loop?"
> >
> > heh :-)
> >
> > Idle enter/exit events are useful to tune power use for example. The
> > more events we have there, the more we prevent the CPU from slowly
> > going into deep sleep mode.

But we could in principle trace idle enter/exit from the scheduler, correct?

That said, it would be possible to allow much of the idle loop to contain
RCU read-side critical sections, but this requires putting rcu_qsctr_inc()
in each and every idle loop, plus catching the cases where idle loops
shut down the CPU. Note that this applies to synchronize_sched() as
well as synchronize_rcu().

> I can say I use it a lot. I'm still needing a way to set the function pid
> recorder to 0 since the conversion to the pid structure. There are times
> I only want to trace the interrupts that happen in the idle loop.

It would be OK to trace the interrupts, just not the idle loop itself.

Thanx, Paul


\
 
 \ /
  Last update: 2009-04-03 20:09    [W:0.058 / U:0.452 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site