From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f54.google.com (mail-pb0-f54.google.com [209.85.160.54]) by kanga.kvack.org (Postfix) with ESMTP id 6A7146B0035 for ; Mon, 3 Feb 2014 21:15:35 -0500 (EST) Received: by mail-pb0-f54.google.com with SMTP id uo5so7840895pbc.13 for ; Mon, 03 Feb 2014 18:15:35 -0800 (PST) Received: from lgemrelse7q.lge.com (LGEMRELSE7Q.lge.com. [156.147.1.151]) by mx.google.com with ESMTP id l8si22609105pao.268.2014.02.03.18.15.31 for ; Mon, 03 Feb 2014 18:15:33 -0800 (PST) Date: Tue, 4 Feb 2014 11:15:33 +0900 From: Joonsoo Kim Subject: Re: [patch] mm, compaction: avoid isolating pinned pages fix Message-ID: <20140204021533.GA14924@lge.com> References: <20140203095329.GH6732@suse.de> <20140204000237.GA17331@lge.com> <20140204015332.GA14779@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Mel Gorman , Andrew Morton , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Mon, Feb 03, 2014 at 06:00:56PM -0800, David Rientjes wrote: > On Tue, 4 Feb 2014, Joonsoo Kim wrote: > > > Okay. It can't fix your situation. Anyway, *normal* anon pages may be mapped > > and have positive page_count(), so your code such as > > '!page_mapping(page) && page_count(page)' makes compaction skip these *normal* > > anon pages and this is incorrect behaviour. > > > > So how does that work with migrate_page_move_mapping() which demands > page_count(page) == 1 and the get_page_unless_zero() in > __isolate_lru_page()? Before doing migrate_page_move_mapping(), try_to_unmap() is called so that all mapping is unmapped. Then, remained page_count() is 1 which is grabbed by __isolate_lru_page(). Am I missing something? Thanks. -- 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