Messages in this thread | | | Date | Sat, 1 Oct 2011 09:35:33 -0700 | From | "Paul E. McKenney" <> | Subject | Re: linux-next-20110923: warning kernel/rcutree.c:1833 |
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On Sat, Oct 01, 2011 at 02:28:10PM +0200, Frederic Weisbecker wrote: > 2011/10/1 Frederic Weisbecker <fweisbec@gmail.com>: > > Yeah something like this (untested): > > > > diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c > > index d5097c4..ad3ecad 100644 > > --- a/kernel/time/tick-sched.c > > +++ b/kernel/time/tick-sched.c > > @@ -273,9 +273,12 @@ void tick_nohz_stop_sched_tick(int inidle) > > * updated. Thus, it must not be called in the event we are called from > > * irq_exit() with the prior state different than idle. > > */ > > - if (!inidle && !ts->inidle) > > + if (inidle) > > + rcu_idle_enter(); > > + else if (!ts->inidle) > > goto end; > > > > + > > /* > > * Set ts->inidle unconditionally. Even if the system did not > > * switch to NOHZ mode the cpu frequency governers rely on the > > @@ -409,7 +412,6 @@ void tick_nohz_stop_sched_tick(int inidle) > > ts->idle_tick = hrtimer_get_expires(&ts->sched_timer); > > ts->tick_stopped = 1; > > ts->idle_jiffies = last_jiffies; > > - rcu_enter_nohz(); > > } > > > > ts->idle_sleeps++; > > @@ -505,6 +507,9 @@ void tick_nohz_restart_sched_tick(void) > > ktime_t now; > > > > local_irq_disable(); > > + > > + rcu_idle_exit(); > > + > > if (ts->idle_active || (ts->inidle && ts->tick_stopped)) > > now = ktime_get(); > > > > @@ -519,8 +524,6 @@ void tick_nohz_restart_sched_tick(void) > > > > ts->inidle = 0; > > > > - rcu_exit_nohz(); > > - > > /* Update jiffies first */ > > select_nohz_load_balancer(0); > > tick_do_update_jiffies64(now); > > > > Ah I see you fixed it in the delta. Ok :)
But rcutorture still hates it. Possibly because of this boneheaded bug:
int rcu_is_cpu_rrupt_from_idle(void) { return (__get_cpu_var(rcu_dynticks).dynticks_nesting & 0x1) <= 1; }
Do you think that it might work better if I drop off the "& 0x1" that I copy-pasted from rcu_is_cpu_idle()? ;-)
Sigh!!! Giving it a try now.
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