From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932561Ab3AJAUq (ORCPT ); Wed, 9 Jan 2013 19:20:46 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:36059 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932441Ab3AJAUo (ORCPT ); Wed, 9 Jan 2013 19:20:44 -0500 Date: Wed, 9 Jan 2013 16:20:42 -0800 From: Andrew Morton To: Minchan Kim Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dan Magenheimer , Sonny Rao , Bryan Freed , Hugh Dickins , Rik van Riel , Johannes Weiner Subject: Re: [PATCH 1/2] mm: prevent to add a page to swap if may_writepage is unset Message-Id: <20130109162042.79a9fedd.akpm@linux-foundation.org> In-Reply-To: <1357712474-27595-2-git-send-email-minchan@kernel.org> References: <1357712474-27595-1-git-send-email-minchan@kernel.org> <1357712474-27595-2-git-send-email-minchan@kernel.org> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 9 Jan 2013 15:21:13 +0900 Minchan Kim wrote: > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -780,6 +780,8 @@ static unsigned long shrink_page_list(struct list_head *page_list, > if (PageAnon(page) && !PageSwapCache(page)) { > if (!(sc->gfp_mask & __GFP_IO)) > goto keep_locked; > + if (!sc->may_writepage) > + goto keep_locked; > if (!add_to_swap(page)) > goto activate_locked; > may_enter_fs = 1; We should add a comment here explaining what's going on. But I can't suggest anything which sounds rational because this looks so wrong :(