On Wed, 4 Apr 2007 22:05:40 +0200 "Dmitry Adamushko" <[EMAIL PROTECTED]> wrote:
> Ingo, > > following the conversation on "a redundant reschedule call in > set_user_prio()", > here is a possible approach. > > The patch is somewhat intrusive as it even dares to adapt > TASK_PREEMPTS_CURR(). > > Nevertheless, this adaptation seems to be ok with all the current use-cases. > > Presupposition: TASK_PREEMPTS_CURR(p, rq) will /never/ be used as "a > mere prio comparator" - e.g. to make decisions on which array a task > has to be placed in. > > > ===== > > o Make TASK_PREEMPTS_CURR(task, rq) return "true" only if the task's > prio is higher than the current's one and the task is in the "active" > array. > This ensures we don't make redundant resched_task() calls when the > task is in the "expired" array (as may happen now in set_user_prio(), > rt_mutex_setprio() and pull_task() ) ; > > o generilise conditions for a call to resched_task() in > set_user_nice(), rt_mutex_setprio() and sched_setscheduler() > grief. This patch conflicts seriously with the staircase scheduler in -mm. So to merge it I need to - apply it - then apply a revert-it-again patch - then apply staircase - then ask Con to cook up a staircase-based equivalent of your change. so - your code only gets publically tested in its against-staircase version - the against-mainline version will get merged without having been publically tested outside of staircase which is probably all OK for a 2.6.22-rc1 thing, provided Ingo can give a confident ack. Where are we at with staircase anyway? Is it looking like a 2.6.22 thing? I don't personally think we've yet seen enough serious performance testing to permit a merge, apart from other issues... > --- linux-2.6.21-rc5/kernel/sched-orig.c 2007-04-04 > 18:26:19.000000000 +0200 > +++ linux-2.6.21-rc5/kernel/sched.c 2007-04-04 18:26:43.000000000 +0200 > @@ -168,7 +168,7 @@ unsigned long long __attribute__((weak)) > (MAX_BONUS / 2 + DELTA((p)) + 1) / MAX_BONUS - 1)) > > #define TASK_PREEMPTS_CURR(p, rq) \ > - ((p)->prio < (rq)->curr->prio) > + (((p)->prio < (rq)->curr->prio) && ((p)->array == (rq)->active)) Your patch was wordwrapped and had its tabs replaced with spaces. Please fix your email client. (I might as well make that paragraph my .signature) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
