From: Matthew Wilcox <matthew@wil.cx>
To: zwu.kernel@gmail.com
Cc: viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org,
Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Subject: Re: [PATCH] vfs: simply the code logic
Date: Sat, 21 Jul 2012 10:34:53 -0600 [thread overview]
Message-ID: <20120721163453.GB31693@parisc-linux.org> (raw)
In-Reply-To: <1342885099-22662-1-git-send-email-zwu.kernel@gmail.com>
On Sat, Jul 21, 2012 at 11:38:19PM +0800, zwu.kernel@gmail.com wrote:
> if (offset >= 0 && offset <= size) {
> - if (offset != file->f_pos) {
> - file->f_pos = offset;
> - }
> - retval = offset;
> + retval = file->f_pos = offset;
> }
But now you're writing to f_pos unconditionally. That may cause
cacheline bouncing. NAK.
Plus, you're now using a less-well-known feature of C, so while it's fewer
lines of code, it's not necessarily a simplification.
--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
prev parent reply other threads:[~2012-07-21 16:34 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-21 15:38 [PATCH] vfs: simply the code logic zwu.kernel
2012-07-21 16:34 ` Matthew Wilcox [this message]
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