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From: Peter Zijlstra <peterz@infradead.org>
To: Yong Zhang <yong.zhang0@gmail.com>
Cc: Venkatesh Pallipadi <venki@google.com>,
	Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Balbir Singh <balbir@linux.vnet.ibm.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	linux-kernel@vger.kernel.org, Paul Turner <pjt@google.com>,
	Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH 8/8] Call tick_check_idle before __irq_enter
Date: Mon, 18 Oct 2010 11:15:27 +0200	[thread overview]
Message-ID: <1287393327.29097.1542.camel@twins> (raw)
In-Reply-To: <20101017090545.GA3468@zhy>

On Sun, 2010-10-17 at 17:05 +0800, Yong Zhang wrote:
> On Mon, Oct 04, 2010 at 05:03:23PM -0700, Venkatesh Pallipadi wrote:
> > diff --git a/kernel/softirq.c b/kernel/softirq.c
> > index 267f7b7..6bb7e19 100644
> > --- a/kernel/softirq.c
> > +++ b/kernel/softirq.c
> > @@ -296,10 +296,16 @@ void irq_enter(void)
> >  
> >  	rcu_irq_enter();
> >  	if (idle_cpu(cpu) && !in_interrupt()) {
> > -		__irq_enter();
> > +		/*
> > +		 * Prevent raise_softirq from needlessly waking up ksoftirqd
> > +		 * here, as softirq will be serviced on return from interrupt.
> > +		 */
> > +		local_bh_disable();
> >  		tick_check_idle(cpu);
> > -	} else
> > -		__irq_enter();
> > +		local_bh_enable();
> 
> 		_local_bh_enable()
> 
> local_bh_enable() could invoke do_softirq().

This seems to indeed cure that explosion.. Thanks!



  reply	other threads:[~2010-10-18  9:15 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-05  0:03 Proper kernel irq time accounting -v4 Venkatesh Pallipadi
2010-10-05  0:03 ` [PATCH 1/8] si time accounting accounts bh_disable'd time to si -v4 Venkatesh Pallipadi
2010-10-18 19:24   ` [tip:sched/core] sched: Fix softirq time accounting tip-bot for Venkatesh Pallipadi
2010-10-05  0:03 ` [PATCH 2/8] Consolidate account_system_vtime extern declaration -v4 Venkatesh Pallipadi
2010-10-18 19:24   ` [tip:sched/core] sched: Consolidate account_system_vtime extern declaration tip-bot for Venkatesh Pallipadi
2010-10-18 19:27   ` [tip:sched/core] sched: Export account_system_vtime() tip-bot for Ingo Molnar
2010-10-05  0:03 ` [PATCH 3/8] Add a PF flag for ksoftirqd identification Venkatesh Pallipadi
2010-10-15 14:26   ` Peter Zijlstra
2010-10-15 14:46   ` Eric Dumazet
2010-10-18 19:25   ` [tip:sched/core] sched: " tip-bot for Venkatesh Pallipadi
2010-10-05  0:03 ` [PATCH 4/8] Add IRQ_TIME_ACCOUNTING, finer accounting of irq time -v4 Venkatesh Pallipadi
2010-10-15 14:28   ` Peter Zijlstra
2010-10-18 19:25   ` [tip:sched/core] sched: Add IRQ_TIME_ACCOUNTING, finer accounting of irq time tip-bot for Venkatesh Pallipadi
2010-10-05  0:03 ` [PATCH 5/8] x86: Add IRQ_TIME_ACCOUNTING in x86 -v4 Venkatesh Pallipadi
2010-10-15 14:38   ` Peter Zijlstra
2010-10-18 19:26   ` [tip:sched/core] x86: Add IRQ_TIME_ACCOUNTING tip-bot for Venkatesh Pallipadi
2010-10-05  0:03 ` [PATCH 6/8] sched: Do not account irq time to current task -v4 Venkatesh Pallipadi
2010-10-18 19:26   ` [tip:sched/core] sched: Do not account irq time to current task tip-bot for Venkatesh Pallipadi
2010-11-29  8:45     ` Yong Zhang
2010-11-29 11:59       ` Peter Zijlstra
2010-11-29 14:22         ` Yong Zhang
2010-11-29 17:06           ` Raistlin
2010-11-30  5:57             ` Yong Zhang
2010-12-01 18:55               ` Venkatesh Pallipadi
2010-12-01 19:16                 ` Peter Zijlstra
2010-10-05  0:03 ` [PATCH 7/8] sched: Remove irq time from available CPU power -v4 Venkatesh Pallipadi
2010-10-18 19:26   ` [tip:sched/core] sched: Remove irq time from available CPU power tip-bot for Venkatesh Pallipadi
2010-10-05  0:03 ` [PATCH 8/8] Call tick_check_idle before __irq_enter Venkatesh Pallipadi
2010-10-17  9:05   ` Yong Zhang
2010-10-18  9:15     ` Peter Zijlstra [this message]
2010-10-18 19:27   ` [tip:sched/core] sched: " tip-bot for Venkatesh Pallipadi
2010-10-12 19:00 ` Proper kernel irq time accounting -v4 Venkatesh Pallipadi
2010-10-14 16:12 ` Shaun Ruffell
2010-10-14 18:19   ` Venkatesh Pallipadi
2010-10-14 20:00     ` Shaun Ruffell
2010-10-15 15:11 ` Peter Zijlstra
2010-10-15 15:27   ` Peter Zijlstra
2010-10-15 17:13     ` Venkatesh Pallipadi
2010-10-15 17:20       ` Peter Zijlstra
2010-10-17  9:11       ` Yong Zhang

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