From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752078AbWFWVYl (ORCPT ); Fri, 23 Jun 2006 17:24:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752080AbWFWVYl (ORCPT ); Fri, 23 Jun 2006 17:24:41 -0400 Received: from smtp.osdl.org ([65.172.181.4]:14527 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1752078AbWFWVYk (ORCPT ); Fri, 23 Jun 2006 17:24:40 -0400 Date: Fri, 23 Jun 2006 14:24:30 -0700 From: Andrew Morton To: Jeff Garzik Cc: linux-kernel@vger.kernel.org, torvalds@osdl.org Subject: Re: [PATCH] ext3_clear_inode(): avoid kfree(NULL) Message-Id: <20060623142430.333dd666.akpm@osdl.org> In-Reply-To: <449C3817.2030802@garzik.org> References: <200606231502.k5NF2jfO007109@hera.kernel.org> <449C3817.2030802@garzik.org> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.17; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 23 Jun 2006 14:51:03 -0400 Jeff Garzik wrote: > Linux Kernel Mailing List wrote: > > commit e6022603b9aa7d61d20b392e69edcdbbc1789969 > > tree f94b059e312ea7b2f3c4d0b01939e868ed525fb0 > > parent 304c4c841a31c780a45d65e389b07706babf5d36 > > author Andrew Morton Fri, 23 Jun 2006 16:05:32 -0700 > > committer Linus Torvalds Fri, 23 Jun 2006 21:43:05 -0700 > > > > [PATCH] ext3_clear_inode(): avoid kfree(NULL) > > > > Steven Rostedt points out that `rsv' here is usually > > NULL, so we should avoid calling kfree(). > > > > Also, fix up some nearby whitespace damage. > > > > Signed-off-by: Andrew Morton > > Signed-off-by: Linus Torvalds > > Dumb question... why? kfree(NULL) has always been explicitly allowed. > Because at that callsite, NULL is the common case. We avoid a do-nothing function call most of the time. It's a nano-optimisation.