Messages in this thread | | | Date | Mon, 12 Mar 2007 12:04:17 +0100 | From | Ingo Molnar <> | Subject | Re: [patch] change futex_wait() to hrtimers |
| |
* Andi Kleen <andi@firstfloor.org> wrote:
> On Mon, Mar 12, 2007 at 12:00:20PM +0100, Thomas Gleixner wrote: > > On Mon, 2007-03-12 at 12:27 +0100, Andi Kleen wrote: > > > Ingo Molnar <mingo@elte.hu> writes: > > > > > > > > the only correct approach is the use of hrtimers, and a patch exists for > > > > that - see below. This has been included in -rt for quite some time. > > > > > > But isn't that bad for power management? You'll likely get more > > > idle wakeups, won't you? > > > > Why so ? It comes more precise, but only once. > > When it's clustered around the jiffies interval then wakeups from > multiple processes will be somewhat batched. With a precise wakeup > you'll get wakeups all over the jiffies period, won't you?
if HIGH_RES_TIMERS is disabled then that is what happens. But frankly, most futex waits are without timeouts - if an application cares about micro-effects like that then you are much better off not using a per-futex timeout anyway.
Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |