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Groups > linux.kernel > #1270272
| From | Thomas Gleixner <tglx@linutronix.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 2/4] timer: relax tick stop in idle entry |
| Date | 2015-11-16 16:10 +0100 |
| Message-ID | <qvtzQ-sT-25@gated-at.bofh.it> (permalink) |
| References | <qusFP-2eI-3@gated-at.bofh.it> <qusFP-2eI-1@gated-at.bofh.it> <qut8T-2FM-15@gated-at.bofh.it> <quv0Z-3RA-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Fri, 13 Nov 2015, Jacob Pan wrote:
> <idle>-0 [000] 30.093473: bprint: __tick_nohz_idle_enter: JPAN: __tick_nohz_idle_enter 803
> <idle>-0 [000] 30.093473: bprint: __tick_nohz_idle_enter: JPAN: can_stop_idle_tick 743
> [JP] can_stop_idle_tick() checks ok to stop tick
>
> <idle>-0 [000] 30.093474: bprint: __tick_nohz_idle_enter: JPAN: tick_nohz_stop_sched_tick 609 delta 1000000
> [JP] but sees delta is exactly 1 tick away. didn't stop tick.
If the delta is 1 tick then it is not supposed to stop it. Did you
ever try to figure out WHY it is 1 tick?
There are two code pathes which can set it to basemono + TICK_NSEC:
if (rcu_needs_cpu(basemono, &next_rcu) ||
arch_needs_cpu() || irq_work_needs_cpu()) {
next_tick = basemono + TICK_NSEC;
} else {
next_tmr = get_next_timer_interrupt(basejiff, basemono);
ts->next_timer = next_tmr;
/* Take the next rcu event into account */
next_tick = next_rcu < next_tmr ? next_rcu : next_tmr;
}
Can you please figure out WHY the tick is requested to continue
instead of blindly wreckaging the logic in that code?
Thanks,
tglx
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[PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-13 21:00 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Thomas Gleixner <tglx@linutronix.de> - 2015-11-13 21:30 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-13 23:30 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Thomas Gleixner <tglx@linutronix.de> - 2015-11-16 16:10 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-16 23:00 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Thomas Gleixner <tglx@linutronix.de> - 2015-11-16 23:10 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-17 01:20 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-19 18:50 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Peter Zijlstra <peterz@infradead.org> - 2015-11-19 20:10 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-19 20:30 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Peter Zijlstra <peterz@infradead.org> - 2015-11-19 21:00 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-20 00:50 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-11-16 23:40 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-17 00:10 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-17 00:20 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-11-17 00:30 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Arjan van de Ven <arjan@linux.intel.com> - 2015-11-17 00:40 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-17 00:50 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-11-17 01:10 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Josh Triplett <josh@joshtriplett.org> - 2015-11-16 23:40 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-11-17 00:30 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Josh Triplett <josh@joshtriplett.org> - 2015-11-17 02:50 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Arjan van de Ven <arjan@linux.intel.com> - 2015-11-17 04:00 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-11-17 06:10 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Peter Zijlstra <peterz@infradead.org> - 2015-11-17 11:30 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry Jacob Pan <jacob.jun.pan@linux.intel.com> - 2015-11-17 14:00 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-11-17 14:50 +0100
Re: [PATCH 2/4] timer: relax tick stop in idle entry "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2015-11-17 04:00 +0100
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