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Date: Tue, 11 Oct 2011 14:54:41 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Manfred Spraul <manfred@colorfullife.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Thomas Gleixner <tglx@linutronix.de>,
        Mike Galbraith <efault@gmx.de>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH 2/3] ipc/sem.c: handle spurious wakeups
Message-Id: <20111011145441.228e4c94.akpm@linux-foundation.org>
In-Reply-To: <1316885831-11996-1-git-send-email-manfred@colorfullife.com>
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On Sat, 24 Sep 2011 19:37:11 +0200
Manfred Spraul <manfred@colorfullife.com> wrote:

> semtimedop() does not handle spurious wakeups, it returns -EINTR to user space.
> Most other schedule() users would just loop and not return to user space.
> The patch adds such a loop to semtimedop()

What is a "spurious wakeup" and how can a process receive one?

I'm wondering about the userspace-visible effects of this change, and
any compatibility issues?