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Date: Tue, 12 Aug 2008 20:49:00 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Huang Ying <ying.huang@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>, Pavel Machek <pavel@ucw.cz>,
       nigel@nigel.suspend2.net, "Rafael J. Wysocki" <rjw@sisk.pl>,
       Vivek Goyal <vgoyal@redhat.com>, mingo@elte.hu,
       Linus Torvalds <torvalds@linux-foundation.org>,
       linux-kernel@vger.kernel.org,
       Kexec Mailing List <kexec@lists.infradead.org>
Subject: Re: [PATCH -v3 1/7] kexec jump: clean up #ifdef and comments
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On Tue, 12 Aug 2008 11:14:21 +0800 Huang Ying <ying.huang@intel.com> wrote:

>  	xchg(&kexec_lock, 0);

kernel/kexec.c: In function 'kernel_kexec':
kernel/kexec.c:1501: warning: value computed is not used

Is there any reason why we cannot use the more conventional
test_and_set_bit() etc, rather than this peculiarity?

Or perhaps spin_trylock?