From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx168.postini.com [74.125.245.168]) by kanga.kvack.org (Postfix) with SMTP id 85E516B0032 for ; Wed, 31 Jul 2013 10:45:35 -0400 (EDT) Received: by mail-pd0-f175.google.com with SMTP id 5so834508pdd.6 for ; Wed, 31 Jul 2013 07:45:34 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <51F7ED29.7080606@intel.com> References: <1375022906-1164-1-git-send-email-waydi1@gmail.com> <51F6F087.9060109@linux.intel.com> <51F70A9F.2000309@linux.vnet.ibm.com> <51F714D4.9070005@linux.vnet.ibm.com> <51F7ED29.7080606@intel.com> Date: Wed, 31 Jul 2013 23:45:34 +0900 Message-ID: Subject: Re: [PATCH 2/2] mm: page_alloc: Add unlikely for MAX_ORDER check From: =?EUC-KR?B?wMy9wsjG?= Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: Cody P Schafer , Dave Hansen , linux-mm@kvack.org, KOSAKI Motohiro , David Rientjes , xinxing2zhou@gmail.com I submit the patch to make sure "order >= MAX_ORDER" happen unlikely. But, I couldn't think generated code by compiler. I think I was wrong. Thanks your comments. 2013/7/31 Dave Hansen : > Cody, it's a good point that we shouldn't be looking at something as > simplistic as the file sizes. I also used whole vmlinux's and turned > off debuginfo: > > text data bss dec hex filename > 10064322 1980968 3051520 15096810 e65bea vmlinux.nothing > 10064451 1980968 3051520 15096939 e65c6b vmlinux.unlikely > > So it still cost ~130 bytes of text. Also, perusing the vmlinux > objdump, adding the unlikely() does look to take > __alloc_pages_direct_compact and move it _closer_ to the page allocation > code. > > What does this all mean? Hell if I know. It's up to the patch > submitter to explain the implications of the patch. ;) > > -- 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