Messages in this thread | | | Date | Tue, 22 Jul 2008 05:54:21 -0700 | From | Arjan van de Ven <> | Subject | Re: [RFC] Imprecise timers. |
| |
On Tue, 22 Jul 2008 09:19:02 +0200 Rene Herman <rene.herman@keyaccess.nl> wrote:
> On 22-07-08 05:02, David Woodhouse wrote: > > > 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. > > Are there actually users for this (not just in theory)? The > deferrable timer sort of sounds like all I'd ever want if I, as you > say, wouldn't really care...
there's a few; mostly around hardware timeout..For example Stephen want it for his drivers.
EXT3 journal flushing is another one where we can easily say "between 4 and 7 seconds" rather than "exactly at 5"
-- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org
| |