From: Johannes Weiner <hannes@cmpxchg.org>
To: Xiaotian Feng <dfeng@redhat.com>
Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] block: slightly optimize blkdev_ioctl BLKRA{SET,GET}
Date: Tue, 14 Jul 2009 16:08:39 +0200 [thread overview]
Message-ID: <20090714140839.GA18146@cmpxchg.org> (raw)
In-Reply-To: <1247572794-24107-1-git-send-email-dfeng@redhat.com>
On Tue, Jul 14, 2009 at 07:59:54PM +0800, Xiaotian Feng wrote:
> Slightly optimize blkdev_ioctl by using shift instead of multiply
> and divide.
Does it make an actual difference in the object code for you? I don't
have a single multiplication in that function after compilation.
Hannes
next prev parent reply other threads:[~2009-07-14 14:09 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-14 11:59 [RFC PATCH] block: slightly optimize blkdev_ioctl BLKRA{SET,GET} Xiaotian Feng
2009-07-14 13:48 ` Américo Wang
2009-07-14 14:08 ` Johannes Weiner [this message]
[not found] <1247572395-24021-1-git-send-email-dfeng@redhat.com>
2009-07-14 14:12 ` Xiaotian Feng
2009-07-17 5:03 ` Tejun Heo
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