From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f44.google.com (mail-qg0-f44.google.com [209.85.192.44]) by kanga.kvack.org (Postfix) with ESMTP id D53306B0031 for ; Thu, 19 Jun 2014 10:29:55 -0400 (EDT) Received: by mail-qg0-f44.google.com with SMTP id j107so2185136qga.3 for ; Thu, 19 Jun 2014 07:29:55 -0700 (PDT) Received: from qmta01.emeryville.ca.mail.comcast.net (qmta01.emeryville.ca.mail.comcast.net. [2001:558:fe2d:43:76:96:30:16]) by mx.google.com with ESMTP id o5si6520366qck.6.2014.06.19.07.29.54 for ; Thu, 19 Jun 2014 07:29:55 -0700 (PDT) Date: Thu, 19 Jun 2014 09:29:52 -0500 (CDT) From: Christoph Lameter 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: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Rasmus Villemoes , linux-mm@kvack.org, 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org