Messages in this thread | | | Date | Fri, 23 Sep 2011 12:29:35 -0700 | From | Arjan van de Ven <> | Subject | Re: [RFC] Introduce greedy hrtimer walk on idle |
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On 9/23/2011 11:54 AM, Venkatesh Pallipadi wrote: > Current hrtimer range timers reduces the number of timer interrupts by > grouping together softexpired timers until the next unexpired timer. > It does not look at softexpired timers that may be after the unexpired > timer in the rbtree. > > Specifically, as the comment in hrtimer.c says > * The immediate goal for using the softexpires is > * minimizing wakeups, not running timers at the > * earliest interrupt after their soft expiration. > * This allows us to avoid using a Priority Search > * Tree, which can answer a stabbing querry for > * overlapping intervals and instead use the simple > * BST we already have. > * We don't add extra wakeups by delaying timers that > * are right-of a not yet expired timer, because that > * timer will have to trigger a wakeup anyway. >
Since you found that it now makes a difference, I'm all for it.. Acked-by: Arjan van de Ven <arjan@linux.intel.com>
(at original introduction it was in the noise, but usage patterns clearly changed a lot and ranges are much more prevalent now)
I would not do the sysctl/configurability thing though.... that's not worth it.
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