From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx201.postini.com [74.125.245.201]) by kanga.kvack.org (Postfix) with SMTP id AFBBA6B0032 for ; Fri, 2 Aug 2013 16:47:22 -0400 (EDT) Date: Fri, 2 Aug 2013 16:47:10 -0400 From: Johannes Weiner Subject: Re: [PATCH 1/4] mm, page_alloc: add likely macro to help compiler optimization Message-ID: <20130802204710.GX715@cmpxchg.org> References: <1375409279-16919-1-git-send-email-iamjoonsoo.kim@lge.com> <20130802162722.GA29220@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130802162722.GA29220@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Joonsoo Kim , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim , Minchan Kim , Mel Gorman , Rik van Riel On Fri, Aug 02, 2013 at 06:27:22PM +0200, Michal Hocko wrote: > On Fri 02-08-13 11:07:56, Joonsoo Kim wrote: > > We rarely allocate a page with ALLOC_NO_WATERMARKS and it is used > > in slow path. For making fast path more faster, add likely macro to > > help compiler optimization. > > The code is different in mmotm tree (see mm: page_alloc: rearrange > watermark checking in get_page_from_freelist) Yes, please rebase this on top. > Besides that, make sure you provide numbers which prove your claims > about performance optimizations. Isn't that a bit overkill? We know it's a likely path (we would deadlock constantly if a sizable portion of allocations were to ignore the watermarks). Does he have to justify that likely in general makes sense? -- 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