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From: Stelian Pop <stelian@popies.net>
To: paulmck@us.ibm.com
Cc: Mike Christie <michaelc@cs.wisc.edu>,
	linux-kernel@vger.kernel.org, akpm@osdl.org, paulus@au1.ibm.com,
	anton@au1.ibm.com, open-iscsi@googlegroups.com,
	pradeep@us.ibm.com, mashirle@us.ibm.com
Subject: Re: [PATCH] memory ordering in __kfifo primitives
Date: Thu, 10 Aug 2006 16:26:53 +0200	[thread overview]
Message-ID: <1155220013.1108.4.camel@localhost.localdomain> (raw)
In-Reply-To: <20060810134135.GB1298@us.ibm.com>

Le jeudi 10 août 2006 à 06:41 -0700, Paul E. McKenney a écrit :

> I am happy to go either way -- the patch with the memory barriers
> (which does have the side-effect of slowing down kfifo_get() and
> kfifo_put(), by the way), or a patch removing the comments saying
> that it is OK to invoke __kfifo_get() and __kfifo_put() without
> locking.
> 
> Any other thoughts on which is better?  (1) the memory barriers or
> (2) requiring the caller hold appropriate locks across calls to
> __kfifo_get() and __kfifo_put()?

If someone wants to use explicit locking, he/she can go with kfifo_get()
instead of the __ version.

I'd rather keep the __kfifo_get() and __kfifo_put() functions lockless,
so I say go for (1) even if there is a tiny price to pay for corectness.

Stelian.
-- 
Stelian Pop <stelian@popies.net>


  reply	other threads:[~2006-08-10 14:26 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-08-10  0:18 [PATCH] memory ordering in __kfifo primitives Paul E. McKenney
2006-08-10  0:29 ` Andrew Morton
2006-08-10  1:01   ` Paul E. McKenney
2006-08-10  0:33 ` Paul E. McKenney
2006-08-10  5:48   ` Mike Christie
2006-08-10 13:41     ` Paul E. McKenney
2006-08-10 14:26       ` Stelian Pop [this message]
2006-08-10 15:39         ` Paul E. McKenney
2006-08-10 15:47           ` Stelian Pop
2006-08-10 16:11             ` Paul E. McKenney
2006-08-10 16:23               ` Stelian Pop
2006-08-10 16:47                 ` Paul E. McKenney
2006-08-10 20:27                   ` Stelian Pop
2006-08-10 20:54                     ` Paul E. McKenney

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