Messages in this thread | | | Date | Fri, 30 Nov 2012 12:36:35 +0100 (CET) | From | Lukáš Czerner <> | Subject | Re: [PATCH 1/2 v3] wait: add wait_event_lock_irq() interface |
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On Fri, 30 Nov 2012, Andrew Morton wrote:
> Date: Fri, 30 Nov 2012 02:48:42 -0800 > From: Andrew Morton <akpm@linux-foundation.org> > To: Lukas Czerner <lczerner@redhat.com> > Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, axboe@kernel.dk, > jmoyer@redhat.com, Neil Brown <neilb@suse.de>, > David Howells <dhowells@redhat.com>, Ingo Molnar <mingo@elte.hu>, > Peter Zijlstra <a.p.zijlstra@chello.nl> > Subject: Re: [PATCH 1/2 v3] wait: add wait_event_lock_irq() interface > > On Fri, 30 Nov 2012 11:42:40 +0100 Lukas Czerner <lczerner@redhat.com> wrote: > > > New wait_event{_interruptible}_lock_irq{_cmd} macros added. This commit > > moves the private wait_event_lock_irq() macro from MD to regular wait > > includes, introduces new macro wait_event_lock_irq_cmd() instead of using > > the old method with omitting cmd parameter which is ugly and makes a use > > of new macros in the MD. It also introduces the _interruptible_ variant. > > > > The use of new interface is when one have a special lock to protect data > > structures used in the condition, or one also needs to invoke "cmd" > > before putting it to sleep. > > > > All new macros are expected to be called with the lock taken. The lock > > is released before sleep and is reacquired afterwards. We will leave the > > macro with the lock held. > > > > Note to DM: IMO this should also fix theoretical race on waitqueue while > > using simultaneously wait_event_lock_irq() and wait_event() because of > > lack of locking around current state setting and wait queue removal. > > Does this fix the sparse warning which Fengguang just sent us?
Which report from Fengguang do you have in mind ? I do not see any on linux-kernel today.
/me going to see what spare reports
-Lukas
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