From: jing zhang Subject: Re: [PATCH] ext4: remove unnecessary operation in ext4_mb_normalize_group_request() Date: Fri, 26 Mar 2010 21:44:33 +0800 Message-ID: References: <87wrwzv732.fsf@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-ext4 , "Theodore Ts'o" , Andreas Dilger , Dave Kleikamp To: "Aneesh Kumar K. V" Return-path: Received: from mail-yx0-f191.google.com ([209.85.210.191]:32795 "EHLO mail-yx0-f191.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754005Ab0CZNoi (ORCPT ); Fri, 26 Mar 2010 09:44:38 -0400 Received: by yxe29 with SMTP id 29so825322yxe.4 for ; Fri, 26 Mar 2010 06:44:34 -0700 (PDT) In-Reply-To: <87wrwzv732.fsf@linux.vnet.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 2010/3/26, Aneesh Kumar K. V : > On Thu, 25 Mar 2010 22:54:21 +0800, jing zhang wrote: >> From: Jing Zhang >> >> Date: Wed Mar 25 22:55:04 2010 >> >> Checking bug seems not at right place, and the function itself should >> be inlined. >> >> Cc: Theodore Ts'o >> Cc: Andreas Dilger >> Cc: Dave Kleikamp >> Cc: "Aneesh Kumar K. V" >> Signed-off-by: Jing Zhang >> >> --- >> >> --- linux-2.6.32/fs/ext4/mballoc.c 2009-12-03 11:51:22.000000000 +0800 >> +++ ext4_mm_leak/mballoc-10.c 2010-03-25 22:44:00.000000000 +0800 >> @@ -2786,9 +2786,7 @@ out_err: >> static void ext4_mb_normalize_group_request(struct >> ext4_allocation_context *ac) >> { >> struct super_block *sb = ac->ac_sb; >> - struct ext4_locality_group *lg = ac->ac_lg; >> >> - BUG_ON(lg == NULL); >> if (EXT4_SB(sb)->s_stripe) >> ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_stripe; >> else > > That BUG_ON is to ensure that the allocation context is actually having > a locality group which is needed for group allocation request. > > -aneesh > Please check 1, the 3 lines at the end of ext4_mb_group_or_file() 2, the function name of this patch - zj