From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx146.postini.com [74.125.245.146]) by kanga.kvack.org (Postfix) with SMTP id 4A97E6B004D for ; Mon, 30 Jul 2012 15:30:38 -0400 (EDT) Date: Mon, 30 Jul 2012 14:30:35 -0500 (CDT) From: Christoph Lameter Subject: Re: [RESEND PATCH 2/4 v3] mm: fix possible incorrect return value of migrate_pages() syscall In-Reply-To: Message-ID: References: <1343411703-2720-1-git-send-email-js1304@gmail.com> <1343411703-2720-2-git-send-email-js1304@gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: JoonSoo Kim Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sasha Levin , Michael Kerrisk On Sat, 28 Jul 2012, JoonSoo Kim wrote: > 2012/7/28 Christoph Lameter : > > On Sat, 28 Jul 2012, Joonsoo Kim wrote: > > > >> do_migrate_pages() can return the number of pages not migrated. > >> Because migrate_pages() syscall return this value directly, > >> migrate_pages() syscall may return the number of pages not migrated. > >> In fail case in migrate_pages() syscall, we should return error value. > >> So change err to -EBUSY > > > > Lets leave this alone. This would change the migrate_pages semantics > > because a successful move of N out of M pages would be marked as a > > total failure although pages were in fact moved. > > > > Okay. > Then, do we need to fix man-page of migrate_pages() syscall? > According to man-page, only returning 0 or -1 is valid. > Without this patch, it can return positive value. Yes the manpage needs updating to say that it can return the number of pages not migrated. -- 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