From: Andrew Morton <akpm@osdl.org>
To: Ingo Molnar <mingo@redhat.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>,
lkml <linux-kernel@vger.kernel.org>,
ak@suse.de
Subject: Re: [PATCH -mm] x86_64 UP needs smp_call_function_single
Date: Thu, 30 Nov 2006 01:35:31 -0800 [thread overview]
Message-ID: <20061130013531.6bb73f53.akpm@osdl.org> (raw)
In-Reply-To: <1164878540.11036.29.camel@earth>
On Thu, 30 Nov 2006 10:22:20 +0100
Ingo Molnar <mingo@redhat.com> wrote:
> >
> > btw, does anyone know why the SMP versions of this function use
> > spin_lock_bh(&call_lock)?
>
> that makes no sense (neither the get_cpu()/put_cpu() gymnastics) if this
> is called with irqs disabled all the time.
smp_call_function_single() must be called with local interrupts ENabled.
But why isn't it just spin_lock()?
<looks>
Eric simply copied that code from ia64, which added the spin_lock_bh()
in 2.4.8. Ho-hum.
next prev parent reply other threads:[~2006-11-30 9:35 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-30 1:01 [PATCH -mm] x86_64 UP needs smp_call_function_single Randy Dunlap
2006-11-30 1:45 ` Andrew Morton
2006-11-30 7:00 ` Ingo Molnar
2006-11-30 7:54 ` Andrew Morton
2006-11-30 9:22 ` Ingo Molnar
2006-11-30 9:35 ` Andrew Morton [this message]
2006-11-30 22:11 ` Randy Dunlap
2006-11-30 22:27 ` Andrew Morton
2006-11-30 22:31 ` Randy Dunlap
2006-11-30 23:14 ` Randy Dunlap
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