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Date: Thu, 04 Jul 2013 11:08:37 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Linus Torvalds <torvalds@linux-foundation.org>
CC: Dave Jones <davej@redhat.com>, Linux Kernel <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: scheduling while atomic & hang.
References: <20130704015525.GA8486@redhat.com> <CA+55aFykwkTVtZuoCEvwpF+5q1LUscw1shkWNPtGdHu+1DgDJA@mail.gmail.com>
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On 07/03/2013 07:49 PM, Linus Torvalds wrote:
>>  [<ffffffff816f42bf>] __schedule+0x94f/0x9c0
>>  [<ffffffff816f487e>] schedule_user+0x2e/0x70
>>  [<ffffffff816f6de4>] retint_careful+0x12/0x2e

This call trace does indeed indicate that we took a hardware interrupt 
which caused a reschedule.  It doesn't necessarily have to be a quantum 
expiration interrupt, it could just as easily be an I/O completion 
interrupt.

	-hpa