From: Oliver Neukum <oneukum@suse.de>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-kernel@vger.kernel.org
Subject: Re: question on read_barrier_depends
Date: Thu, 17 Apr 2014 17:16:07 +0200 [thread overview]
Message-ID: <1397747767.6428.4.camel@linux-fkkt.site> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1404161119490.1334-100000@iolanthe.rowland.org>
On Wed, 2014-04-16 at 11:26 -0400, Alan Stern wrote:
> In addition, the following code in kfifo_get() does this:
>
> *(typeof(__tmp->type))__val = \
> (__is_kfifo_ptr(__tmp) ? \
> ((typeof(__tmp->type))__kfifo->data) : \
> (__tmp->buf) \
> )[__kfifo->out & __tmp->kfifo.mask]; \
> smp_wmb(); \
> __kfifo->out++; \
>
> It looks like the smp_wmb() should really be smp_mb(), because it
> separates the _read_ for val from the _write_ of kfifo->out.
But where is kfifo->out read at all?
Regards
Oliver
next prev parent reply other threads:[~2014-04-17 15:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-16 7:47 Oliver Neukum
2014-04-16 15:26 ` Alan Stern
2014-04-17 15:16 ` Oliver Neukum [this message]
2014-04-17 15:50 ` Alan Stern
2014-04-18 14:02 ` Oliver Neukum
2014-04-18 18:16 ` Alan Stern
2014-04-18 17:17 ` Oliver Neukum
2014-04-21 9:40 ` Oliver Neukum
2014-04-21 14:03 ` Alan Stern
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