On Thu, 12 Mar 2009, Peter Zijlstra wrote: > On Thu, 2009-03-12 at 06:53 -0700, Arjan van de Ven wrote: > > Darren Hart wrote: > > > Commit-ID: 16f4993f4e9860715918efd4eeac928f8de1218b > > > Gitweb: http://git.kernel.org/tip/16f4993f4e9860715918efd4eeac928f8de1218b > > > Author: "Darren Hart" <dvhltc@xxxxxxxxxx> > > > AuthorDate: Thu, 12 Mar 2009 00:55:59 -0700 > > > Commit: Ingo Molnar <mingo@xxxxxxx> > > > CommitDate: Thu, 12 Mar 2009 11:20:57 +0100 > > > > > > futex: use current->time_slack_ns for rt tasks too > > > > > > RT tasks should set their timer slack to 0 on their own. This > > > patch removes the 'if (rt_task()) slack = 0;' block in > > > futex_wait. > > > > Hi, > > > > can you explain the rationale for this reasoning? > > Yeah, I found it iffy as well, I think we want something like the below > instead though.. Yup, that's what I meant when I hollered about the timer_slack_ns hackery in futex.c Thanks, tglx > --- > > Subject: sched: adjust timer_slack_ns on scheduler policy change > From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> > Date: Thu Mar 12 15:01:02 CET 2009 > > Ensure RT tasks have 0 timer slack. > > Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> > --- > kernel/sched.c | 2 ++ > 1 file changed, 2 insertions(+) > > Index: linux-2.6/kernel/sched.c > =================================================================== > --- linux-2.6.orig/kernel/sched.c > +++ linux-2.6/kernel/sched.c > @@ -5511,10 +5511,12 @@ __setscheduler(struct rq *rq, struct tas > case SCHED_NORMAL: > case SCHED_BATCH: > case SCHED_IDLE: > + p->timer_slack_ns = p->default_timer_slack_ns; > p->sched_class = &fair_sched_class; > break; > case SCHED_FIFO: > case SCHED_RR: > + p->timer_slack_ns = 0; > p->sched_class = &rt_sched_class; > break; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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