From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx135.postini.com [74.125.245.135]) by kanga.kvack.org (Postfix) with SMTP id 333336B003D for ; Mon, 17 Jun 2013 19:56:20 -0400 (EDT) Received: by mail-pa0-f53.google.com with SMTP id tj12so3371018pac.12 for ; Mon, 17 Jun 2013 16:56:19 -0700 (PDT) Date: Mon, 17 Jun 2013 16:56:17 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH] mm: Remove unlikely from the current_order test In-Reply-To: <51BF8860.7010909@gmail.com> Message-ID: References: <51BF8860.7010909@gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Zhang Yanfei Cc: Andrew Morton , Linux MM , "linux-kernel@vger.kernel.org" On Tue, 18 Jun 2013, Zhang Yanfei wrote: > From: Zhang Yanfei > > In __rmqueue_fallback(), current_order loops down from MAX_ORDER - 1 > to the order passed. MAX_ORDER is typically 11 and pageblock_order > is typically 9 on x86. Integer division truncates, so pageblock_order / 2 > is 4. For the first eight iterations, it's guaranteed that > current_order >= pageblock_order / 2 if it even gets that far! > > So just remove the unlikely(), it's completely bogus. > > Suggested-by: David Rientjes > Signed-off-by: Zhang Yanfei Acked-by: David Rientjes -- 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