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 AEC5C6B0047 for ; Mon, 6 Sep 2010 10:18:17 -0400 (EDT) Received: by eyh5 with SMTP id 5so2661801eyh.14 for ; Mon, 06 Sep 2010 07:18:16 -0700 (PDT) Date: Mon, 6 Sep 2010 18:18:13 +0400 From: Kulikov Vasiliy Subject: Re: [PATCH 13/14] mm: mempolicy: Check return code of check_range Message-ID: <20100906141813.GB9632@albatros> References: <1283711588-7628-1-git-send-email-segooon@gmail.com> <20100906093610.C8B5.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: David Rientjes Cc: KOSAKI Motohiro , kernel-janitors@vger.kernel.org, Andrew Morton , Lee Schermerhorn , Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Mon, Sep 06, 2010 at 02:02 -0700, David Rientjes wrote: > On Mon, 6 Sep 2010, KOSAKI Motohiro wrote: > > > > From: Vasiliy Kulikov > > > > > > Function check_range may return ERR_PTR(...). Check for it. > > > > When happen this issue? > > > > afaik, check_range return error when following condition. > > 1) mm->mmap->vm_start argument is incorrect > > 2) don't have neigher MPOL_MF_STATS, MPOL_MF_MOVE and MPOL_MF_MOVE_ALL > > > > I think both case is not happen in real. Am I overlooking anything? > > > > There's no reason not to check the return value of a function when the > implementation of either could change at any time. migrate_to_node() is > certainly not in any fastpath where we can't sacrifice a branch for more > robust code. Agreed, if you know that the caller must check input data and must not check return code, it's better to make this function return void. -- Vasiliy -- 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