From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] hardlockup: detect hard lockups without NMIs using secondary cpus
Date: Thu, 10 Jan 2013 14:22:45 +0000 [thread overview]
Message-ID: <20130110142245.GE19944@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20130110140215.GP88797@redhat.com>
On Thu, Jan 10, 2013 at 09:02:15AM -0500, Don Zickus wrote:
> On Wed, Jan 09, 2013 at 05:57:39PM -0800, Colin Cross wrote:
> > Emulate NMIs on systems where they are not available by using timer
> > interrupts on other cpus. Each cpu will use its softlockup hrtimer
> > to check that the next cpu is processing hrtimer interrupts by
> > verifying that a counter is increasing.
> >
> > This patch is useful on systems where the hardlockup detector is not
> > available due to a lack of NMIs, for example most ARM SoCs.
>
> I have seen other cpus, like Sparc I think, create a 'virtual NMI' by
> reserving an IRQ line as 'special' (can not be masked). Not sure if that
> is something worth looking at here (or even possible).
No it isn't, because that assumes that things like spin_lock_irqsave()
won't mask that interrupt. We don't have the facility to do that.
next prev parent reply other threads:[~2013-01-10 14:22 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-10 1:57 [PATCH] hardlockup: detect hard lockups without NMIs using secondary cpus Colin Cross
2013-01-10 14:02 ` Don Zickus
2013-01-10 14:22 ` Russell King - ARM Linux [this message]
2013-01-10 16:18 ` Frederic Weisbecker
2013-01-10 17:00 ` Russell King - ARM Linux
2013-01-10 17:27 ` Colin Cross
2013-01-10 18:17 ` Don Zickus
2013-01-10 20:38 ` Tony Lindgren
2013-01-10 22:34 ` Colin Cross
2013-01-10 23:42 ` Tony Lindgren
2013-01-11 1:39 ` Liu, Chuansheng
2013-01-11 5:34 ` Colin Cross
2013-01-11 5:57 ` Liu, Chuansheng
2013-01-11 6:17 ` Colin Cross
2013-01-11 6:27 ` Liu, Chuansheng
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