From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH v4 09/31] dio: create a dio_aligned() helper function Date: Tue, 4 Dec 2012 04:39:48 +0100 Message-ID: <20121204033948.GC16230@one.firstfloor.org> References: <50BD2283.2080809@oracle.com> <50BD6C3E.8020809@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: hch@infradead.org, linux-fsdevel@vger.kernel.org To: Dave Kleikamp Return-path: Received: from one.firstfloor.org ([213.235.205.2]:36345 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751418Ab2LDDjz (ORCPT ); Mon, 3 Dec 2012 22:39:55 -0500 Content-Disposition: inline In-Reply-To: <50BD6C3E.8020809@oracle.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Mon, Dec 03, 2012 at 09:21:34PM -0600, Dave Kleikamp wrote: > I'm not sure what's preferable here. As the comment states, the code is > making an effort to avoid a cache miss by avoiding the reference to bdev > when possible. If this micro-optimization is worth keeping, then it's a > question of which is uglier, this new function that modifies blkbits, or > duplicating this bit of code three times. The optimization was a quite measurable win on a large OLTP benchmark. I think it's worth keeping. -Andi -- ak@linux.intel.com -- Speaking for myself only.