From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id F34BF600068 for ; Sun, 3 Jan 2010 23:10:23 -0500 (EST) Received: by yxe36 with SMTP id 36so15932981yxe.11 for ; Sun, 03 Jan 2010 20:10:22 -0800 (PST) Message-ID: <4B416A28.70806@gmail.com> Date: Mon, 04 Jan 2010 12:10:16 +0800 From: shijie8 MIME-Version: 1.0 Subject: Re: [PATCH] mm : add check for the return value References: <1262571730-2778-1-git-send-email-shijie8@gmail.com> <20100104122138.f54b7659.minchan.kim@barrios-desktop> In-Reply-To: <20100104122138.f54b7659.minchan.kim@barrios-desktop> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: akpm@linux-foundation.org, mel@csn.ul.ie, linux-mm@kvack.org List-ID: > I think it's not desirable to add new branch in hot-path even though > we could avoid that. > > How about this? > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 4e4b5b3..87976ad 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1244,6 +1244,9 @@ again: > return page; > > failed: > you miss anther place where also uses "goto failed". > + spin_lock(&zone->lock); > + __mod_zone_page_state(zone, NR_FREE_PAGES, 1<< order); > + spin_unlock(&zone->lock); > local_irq_restore(flags); > put_cpu(); > return NULL; > > I also thought over your method before I sent the patch, but there already exits a "if (!page)" , I not sure whether my patch adds too much delay in hot-path. -- 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