lkml.org 
[lkml]   [2008]   [Aug]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC] Imprecise timers.
On Mon 2008-07-28 17:36:57, Pallipadi, Venkatesh wrote:
>
>
> >-----Original Message-----
> >From: linux-kernel-owner@vger.kernel.org
> >[mailto:linux-kernel-owner@vger.kernel.org] On Behalf Of David
> >Woodhouse
> >Sent: Monday, July 21, 2008 8:03 PM
> >To: linux-kernel@vger.kernel.org
> >Cc: Thomas Gleixner; Ingo Molnar; arjan@infradead.org
> >Subject: [RFC] Imprecise timers.
> >
> >Many users of timers don't really care too much about exactly
> >when their
> >timer fires -- and waking a CPU to satisfy such a timer is a waste of
> >power. This patch implements a 'range' timer which will fire
> >at a 'convenient'
> >moment within given constraints.
> >
> >It's implemented by a deferrable timer at the beginning of the range,
> >which will run some time later when the CPU happens to be awake. And a
> >non-deferrable timer at the hard deadline, to ensure it really does
> >happen by then.
> >
>
> One concern I have is drivers using range_timers thinking that they need
> some upper bound, while all they need is a simple deferrable timer. With that
> we will have multiple timers waking up the CPU all the time (say, on
> different CPUs) problem again. Even without the timers waking up all

I don't get it. Who has timers that can be deferred forever? At that
point they may simply not set the timer at all, right?

Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html


\
 
 \ /
  Last update: 2008-08-10 22:05    [from the cache]
©2003-2011 Jasper Spaans