From: Nicholas Mc Guire <der.herr@hofr.at>
To: Prarit Bhargava <prarit@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
Vinod Koul <vinod.koul@intel.com>,
dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] incorrect use of init_completion fixup
Date: Wed, 24 Dec 2014 20:11:07 +0100 [thread overview]
Message-ID: <20141224191107.GA24476@opentech.at> (raw)
In-Reply-To: <549B0DA5.3010700@redhat.com>
On Wed, 24 Dec 2014, Prarit Bhargava wrote:
>
>
> On 12/23/2014 12:52 PM, Nicholas Mc Guire wrote:
> > The successive init_completion calls should be reinit_completion here.
> >
>
> Hi Nicholas,
>
> I know enough about this code to break it ;) ... what condition did you hit that
> led you to this patch?
>
Was writing up documentation for completion (also posted today) and the
intended API is reinit_completion which is just resetting the counter but
not touching the related waitqueu. So the failure scenario would be
a race between accessing elements on the current wait-queue and the
init_completion reinitializing this very wait-queue.
Further if switching from init_completion -> reinit_completion brakes
anything then it really *is* broken now.
thx!
hofrat
next prev parent reply other threads:[~2014-12-24 19:11 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-23 17:52 [PATCH] incorrect use of init_completion fixup Nicholas Mc Guire
2014-12-24 19:01 ` Prarit Bhargava
2014-12-24 19:11 ` Nicholas Mc Guire [this message]
[not found] <49ea5f8dc52545d4a5df6b1ad8302410@HT17-E6.exg6.exghost.com>
2014-12-24 2:14 ` Ed Cashin
-- strict thread matches above, loose matches on Subject: below --
2014-12-23 17:44 Nicholas Mc Guire
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