Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758021AbaFSO35 (ORCPT ); Thu, 19 Jun 2014 10:29:57 -0400 Received: from qmta10.emeryville.ca.mail.comcast.net ([76.96.30.17]:58329 "EHLO qmta10.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757944AbaFSO3z (ORCPT ); Thu, 19 Jun 2014 10:29:55 -0400 Date: Thu, 19 Jun 2014 09:29:52 -0500 (CDT) From: Christoph Lameter To: Tejun Heo cc: Rasmus Villemoes , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: percpu: micro-optimize round-to-even In-Reply-To: <20140619132536.GF11042@htj.dyndns.org> Message-ID: References: <1403172149-25353-1-git-send-email-linux@rasmusvillemoes.dk> <20140619132536.GF11042@htj.dyndns.org> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 19 Jun 2014, Tejun Heo wrote: > On Thu, Jun 19, 2014 at 12:02:29PM +0200, Rasmus Villemoes wrote: > > This change shaves a few bytes off the generated code. > > > > Signed-off-by: Rasmus Villemoes > > --- > > mm/percpu.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/mm/percpu.c b/mm/percpu.c > > index 2ddf9a9..978097f 100644 > > --- a/mm/percpu.c > > +++ b/mm/percpu.c > > @@ -720,8 +720,7 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved) > > if (unlikely(align < 2)) > > align = 2; > > > > - if (unlikely(size & 1)) > > - size++; > > + size += size & 1; > > I'm not gonna apply this. This isn't that hot a path. It's not > worthwhile to micro optimize code like this. Dont we have an ALIGN() macro for this? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/