From: Huang Ying <ying.huang@intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>, "H.PeterA" <"nvin hpa"@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Andi Kleen <andi@firstfloor.org>
Subject: Re: [RFC][PATCH] irq_work
Date: Thu, 24 Jun 2010 15:04:29 +0800 [thread overview]
Message-ID: <1277363069.3947.30.camel@yhuang-dev.sh.intel.com> (raw)
In-Reply-To: <1277362680.1875.845.camel@laptop>
On Thu, 2010-06-24 at 14:58 +0800, Peter Zijlstra wrote:
> On Thu, 2010-06-24 at 14:50 +0800, Huang Ying wrote:
> > On Thu, 2010-06-24 at 14:47 +0800, Peter Zijlstra wrote:
> > > On Thu, 2010-06-24 at 14:43 +0800, Huang Ying wrote:
> > > > Hi, Peter,
> > >
> > > > I fact I uses exactly the similar method in my patches, just trigger it
> > > > with soft_irq instead of IRQ. Please take a look at
> > > > nmi_return_notifier_schedule in
> > >
> > > But then why still use softirq? Once you have this its completely
> > > useless.
> >
> > Some systems have no self interrupt, for example the system without
> > APIC. We need to provide a fallback for them. soft_irq can help here.
>
> So there's systems that don't have self-ipi but do have NMI context?
Yes. NMI is there from 8259 age.
> Can't we run the callbacks from the tick or something for such legacy
> muck? I really don't like the whole softirq mess.
That is possible. But in NO_HZ system, we have no tick to rely on.
soft_irq is better here, because it will be triggered for any interrupt.
Best Regards,
Huang Ying
next prev parent reply other threads:[~2010-06-24 7:04 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-24 3:04 [RFC 1/5] Make soft_irq NMI safe Huang Ying
2010-06-24 3:04 ` [RFC 2/5] NMI return notifier Huang Ying
2010-06-24 3:04 ` [RFC 3/5] x86, trigger NMI return notifier soft_irq earlier Huang Ying
2010-06-24 6:03 ` Peter Zijlstra
2010-06-24 3:04 ` [RFC 4/5] x86, Use NMI return notifier in MCE Huang Ying
2010-06-24 10:00 ` Andi Kleen
2010-06-24 3:04 ` [RFC 5/5] Use NMI return notifier in perf pending Huang Ying
2010-06-24 6:00 ` Peter Zijlstra
2010-06-24 6:09 ` [RFC 1/5] Make soft_irq NMI safe Peter Zijlstra
2010-06-24 6:45 ` Huang Ying
2010-06-24 6:35 ` [RFC][PATCH] irq_work Peter Zijlstra
2010-06-24 6:43 ` Huang Ying
2010-06-24 6:47 ` Peter Zijlstra
2010-06-24 6:50 ` Huang Ying
2010-06-24 6:58 ` Peter Zijlstra
2010-06-24 7:04 ` Huang Ying [this message]
2010-06-24 7:19 ` Peter Zijlstra
2010-06-24 7:27 ` Huang Ying
2010-06-24 7:32 ` Peter Zijlstra
2010-06-24 10:27 ` Andi Kleen
2010-06-24 10:30 ` Peter Zijlstra
2010-06-24 10:52 ` Andi Kleen
2010-06-24 10:58 ` Peter Zijlstra
2010-06-24 11:08 ` Andi Kleen
2010-06-24 11:10 ` Peter Zijlstra
2010-06-24 11:20 ` Andi Kleen
2010-06-24 11:33 ` Peter Zijlstra
2010-06-24 11:55 ` Andi Kleen
2010-06-24 11:57 ` Peter Zijlstra
2010-06-24 12:02 ` Andi Kleen
2010-06-24 12:18 ` Peter Zijlstra
2010-06-24 12:38 ` Andi Kleen
2010-06-25 10:38 ` Peter Zijlstra
2010-06-24 11:42 ` Peter Zijlstra
2010-06-24 11:58 ` Andi Kleen
2010-06-24 12:02 ` Peter Zijlstra
2010-06-24 11:23 ` Ingo Molnar
2010-06-24 11:34 ` Peter Zijlstra
2010-06-24 12:35 ` Ingo Molnar
2010-06-24 13:02 ` Andi Kleen
2010-06-24 13:20 ` Borislav Petkov
2010-06-24 13:33 ` Andi Kleen
2010-06-24 13:42 ` Ingo Molnar
2010-06-24 13:46 ` Ingo Molnar
2010-06-24 14:01 ` Andi Kleen
2010-06-24 15:41 ` Borislav Petkov
2010-06-24 16:09 ` Andi Kleen
2010-06-25 2:12 ` Huang Ying
2010-06-25 7:48 ` Peter Zijlstra
2010-06-25 9:17 ` Huang Ying
2010-06-25 9:23 ` Frederic Weisbecker
2010-06-25 9:30 ` Huang Ying
2010-06-25 9:44 ` Frederic Weisbecker
2010-06-25 9:30 ` Peter Zijlstra
2010-06-25 11:58 ` huang ying
2010-06-25 9:08 ` Andi Kleen
2010-06-25 18:30 ` [RFC][PATCH] irq_work -v2 Peter Zijlstra
2010-06-25 19:30 ` Andi Kleen
2010-06-25 19:39 ` Peter Zijlstra
2010-06-25 19:49 ` Peter Zijlstra
2010-06-25 22:29 ` Andi Kleen
2010-06-26 8:36 ` Peter Zijlstra
2010-06-26 10:08 ` Andi Kleen
2010-06-26 10:32 ` Peter Zijlstra
2010-06-25 19:47 ` Peter Zijlstra
2010-06-26 1:26 ` huang ying
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