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From: Manfred Spraul <manfred@colorfullife.com>
To: Jia He <jiakernel@gmail.com>
Cc: Mike Galbraith <bitbucket@online.de>,
	linux-kernel@vger.kernel.org,
	Davidlohr Bueso <davidlohr.bueso@hp.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Rik van Riel <riel@redhat.com>, Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH] ipc/sem.c: fix update sem_otime when calling sem_op in semaphore initialization
Date: Wed, 25 Sep 2013 08:55:16 +0200	[thread overview]
Message-ID: <524288D4.9090407@colorfullife.com> (raw)
In-Reply-To: <52425316.8060101@gmail.com>

Hi Jia,

On 09/25/2013 05:05 AM, Jia He wrote:
>   Hi Manfred
> IIUC after reivewing your patch and src code, does it seem
> sem_otime lost the chance to be updated when calling
> semctl_main/semctl_setval?
> In old codes, even whendo_smart_update(sma, NULL, 0, 0, &tasks),
> the otime can be updated after several conditions checking.
The update is performed now performed inside perform_atomic_semop():

Old code:
perform_atomic_semop() does not update sem_otime. It just returns 0 for 
successfull operations.
This "0 returned" is passed upwards ("semop_completed") into 
do_smart_update()
do_smart_update() updates sem_otime.

New code:
perform_atomic_semop() updates sem_otime immediately (your change).
No need to keep track if a waiting operation was completed (my change).

I don't see a problem - perhaps I overlook something.
Which problem do you see?

--
     Manfred


  reply	other threads:[~2013-09-25  6:55 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-22  2:11 Jia He
2013-09-22  8:17 ` Mike Galbraith
2013-09-22  8:26   ` Mike Galbraith
2013-09-22  9:34     ` Jia He
2013-09-22 10:00       ` Mike Galbraith
2013-09-22 12:44         ` Jia He
2013-09-22 10:42     ` Manfred Spraul
2013-09-22 12:53       ` Jia He
2013-09-22 15:14       ` Jia He
2013-09-24 21:09         ` Manfred Spraul
2013-09-25  3:05           ` Jia He
2013-09-25  6:55             ` Manfred Spraul [this message]
2013-09-25  7:49               ` Jia He
2013-09-23  1:08       ` Mike Galbraith
2013-09-23  2:24         ` Jia He

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