From: Chris Metcalf <cmetcalf@tilera•com>
To: Pete Zaitcev <zaitcev@redhat•com>
Cc: Evgeniy Polyakov <zbr@ioremap•net>, Erik Jacobson <erikj@sgi•com>,
Andrew Morton <akpm@osdl•org>, Matt Helsley <matthltc@us•ibm.com>,
<netdev@vger•kernel.org>, <linux-kernel@vger•kernel.org>
Subject: Re: [PATCH] connector: improved unaligned access error fix
Date: Thu, 14 Nov 2013 16:22:32 -0500 [thread overview]
Message-ID: <52853F18.4040605@tilera.com> (raw)
In-Reply-To: <20131114124549.7b5f3a7b@lembas.zaitcev.lan>
On 11/14/2013 2:45 PM, Pete Zaitcev wrote:
> On Thu, 14 Nov 2013 12:09:21 -0500
> Chris Metcalf <cmetcalf@tilera•com> wrote:
>
>> - __u8 buffer[CN_PROC_MSG_SIZE];
>> + __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
>> - msg = (struct cn_msg *)buffer;
>> + msg = buffer_to_cn_msg(buffer);
>> ev = (struct proc_event *)msg->data;
>> memset(&ev->event_data, 0, sizeof(ev->event_data));
> Why is memset(buffer,0,CN_PROC_MSG_SIZE) not acceptable?
That would be fine from a correctness point of view; I'm happy
either way. My patch nominally has better performance, for
what that's worth, since the memset() call is for a smaller
range (24 bytes instead of 60). It also avoids the need for
put_unaligned(), which even on platforms that allow unaligned
stores can still be slower.
I can certainly do a v2 with the larger memset() instead if
that's the consensus.
--
Chris Metcalf, Tilera Corp.
http://www.tilera.com
next prev parent reply other threads:[~2013-11-14 21:22 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-14 17:09 [PATCH] connector: improved unaligned access error fix Chris Metcalf
2013-11-14 19:45 ` Pete Zaitcev
2013-11-14 21:22 ` Chris Metcalf [this message]
2013-11-14 22:20 ` David Miller
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