Re: [PATCH 03/11] locking, rwsem: introduce basis for down_write_killable

From	Michal Hocko <mhocko@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 03/11] locking, rwsem: introduce basis for down_write_killable
Date	2016-04-07 09:40 +0200
Message-ID	<rlcHL-pI-7@gated-at.bofh.it> (permalink)
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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

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Re: [PATCH 03/11] locking, rwsem: introduce basis for  down_write_killable Michal Hocko <mhocko@kernel.org> - 2016-04-04 11:20 +0200
  Re: [PATCH 03/11] locking, rwsem: introduce basis for  down_write_killable Peter Zijlstra <peterz@infradead.org> - 2016-04-04 11:30 +0200
  Re: [PATCH 03/11] locking, rwsem: introduce basis for  down_write_killable Davidlohr Bueso <dave@stgolabs.net> - 2016-04-07 09:00 +0200
    Re: [PATCH 03/11] locking, rwsem: introduce basis for  down_write_killable Michal Hocko <mhocko@kernel.org> - 2016-04-07 09:40 +0200

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