From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keith Owens <kaos@ocs.com.au>
Subject: Re: [PATCH 1/10] Add generic helpers for arch IPI function calls
Date: Fri, 02 May 2008 22:50:44 +1000
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In-reply-to: Your message of "Fri, 02 May 2008 05:29:55 MST."
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Cc: Nick Piggin <npiggin@suse.de>, Jens Axboe <jens.axboe@oracle.com>, linux-kernel@vger.kernel.org, peterz@infradead.org, linux-arch@vger.kernel.org, jeremy@goop.org, mingo@elte.hu

"Paul E. McKenney" (on Fri, 2 May 2008 05:29:55 -0700) wrote:
>OK -- for some reason, I was thinking that it was illegal to
>invoke smp_call_function() with irqs disabled...
>
>Ah, I see it -- smp_call_function_mask() says:
>
> * You must not call this function with disabled interrupts or from a
> * hardware interrupt handler or from a bottom half handler.
>
>So we have no problem with smp_call_function, then.
>
>OK, so smp_call_function() -can- be invoked with irqs disabled?
>Hmmm...  I will give this some thought.

Doing any smp_call_function with interrupts disabled is a potential
deadlock.  See http://lkml.org/lkml/2004/5/2/116.