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Date: Thu, 7 Apr 2016 09:38:40 +0200
From: Michal Hocko <mhocko@kernel.org>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: LKML <linux-kernel@vger.kernel.org>, Peter Zijlstra <peterz@infradead.org>,
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Subject: Re: [PATCH 03/11] locking, rwsem: introduce basis for
 down_write_killable
Message-ID: <20160407073840.GA32755@dhcp22.suse.cz>
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On Wed 06-04-16 23:58:07, Davidlohr Bueso wrote:
> On Mon, 04 Apr 2016, Michal Hocko wrote:
> 
> >Not sure I got your point here.
> 
> You set current to TASK_KILLABLE in the sleep loop, why do you want to change
> it here to TASK_RUNNING if its about to be killed?

Wouldn't it be unexpected to return from a lock with something else than
TASK_RUNNING?

> At least in the case of
> UNINTERRUPTABLE we do it merely as a redundancy after the breaking out of the
> loop. Of course we also acquired the lock in the first place by that time and
> we _better_ be running.

I guess the reason was that rwsem_try_write_lock might suceed and we do
not want to return with TASK_UNINTERRUPTIBLE in that case.

-- 
Michal Hocko
SUSE Labs