From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p67GSSOd182580 for ; Thu, 7 Jul 2011 11:28:28 -0500 Date: Thu, 7 Jul 2011 12:28:24 -0400 From: Christoph Hellwig Subject: Re: [PATCH 23/28] xfs: byteswap constants instead of variables Message-ID: <20110707162824.GA7830@infradead.org> References: <20110707110535.205001532@bombadil.infradead.org> <20110707110645.046387162@bombadil.infradead.org> <1310055860.1980.23.camel@doink> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1310055860.1980.23.camel@doink> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Alex Elder Cc: Christoph Hellwig , xfs@oss.sgi.com On Thu, Jul 07, 2011 at 11:24:20AM -0500, Alex Elder wrote: > On Thu, 2011-07-07 at 07:05 -0400, Christoph Hellwig wrote: > > Micro-optimize various comparisms by always byteswapping the constant > > instead of the variable, which allows to do the swap at compile instead > > of runtime. > > > > Signed-off-by: Christoph Hellwig > > Ha!!! You missed one! File "fs/xfs/xfs_dir2_node.c" > lines 412-413 (after applying this patch): > > ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC); I left a few where we are doing the same byteswap a little later again, but this one doesn't seem to fall into the category. Oh, I see why now: my grep only found the _MAGIC and the byteswap on the same line. > Also, xfs_magics[] in "fs/xfs/xfs_btree.c" could be > initialized with the pre-byte-swapped versions of > the constants (and the array should be given static > scope as well). Yeah, but let's keep this patch simple for now. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs