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Date: Fri, 11 Mar 2005 02:07:17 -0800
From: Andrew Morton <akpm@osdl.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: arjan@infradead.org, pbadari@us.ibm.com, dhowells@redhat.com,
       torvalds@osdl.org, suparna@in.ibm.com, linux-aio@kvack.org,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH] rwsem: Make rwsems use interrupt disabling spinlocks
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Ingo Molnar <mingo@elte.hu> wrote:
>
> 
> * Arjan van de Ven <arjan@infradead.org> wrote:
> 
> > > Ingo, we already have a touch_nmi_watchdog() in the sysrq code.  It might be
> > > worth adding a touch_softlockup_watchdog() wherever we have a
> > > touch_nmi_watchdog().
> > 
> > ....or add touch_softlockup_watchdog to touch_nmi_watchdog() instead
> > and rename it tickle_watchdog() overtime.
> 
> you mean like:
> 
> +extern void touch_softlockup_watchdog(void);
> 
> in:
> 
>  http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.11/2.6.11-mm2/broken-out/detect-soft-lockups.patch
> 
> ?
> 

Nope.

This particular lockup happened because a huge stream of stuff was sent to
the serial console.

We already have a touch_nmi_watchdog() in that code.

We should arrange for touch_softlockup_watchdog() to be called whenever
touch_nmi_watchdog() is called.