Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753790Ab1FHJi3 (ORCPT ); Wed, 8 Jun 2011 05:38:29 -0400 Received: from cantor2.suse.de ([195.135.220.15]:53113 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753086Ab1FHJi2 (ORCPT ); Wed, 8 Jun 2011 05:38:28 -0400 Date: Wed, 8 Jun 2011 11:38:27 +0200 From: Michal Hocko To: Mel Gorman Cc: Andrew Morton , Andrea Arcangeli , Minchan Kim , Thomas Sattler , Ury Stankevich , Andi Kleen , linux-mm , linux-kernel Subject: Re: [PATCH 2/4] mm: vmscan: Do not use page_count without a page pin Message-ID: <20110608093827.GD6742@tiehlicka.suse.cz> References: <1307459225-4481-1-git-send-email-mgorman@suse.de> <1307459225-4481-3-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1307459225-4481-3-git-send-email-mgorman@suse.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 876 Lines: 26 On Tue 07-06-11 16:07:03, Mel Gorman wrote: > From: Andrea Arcangeli > > From: Andrea Arcangeli > > It is unsafe to run page_count during the physical pfn scan because > compound_head could trip on a dangling pointer when reading > page->first_page if the compound page is being freed by another CPU. > > [mgorman@suse.de: Split out patch] > Signed-off-by: Andrea Arcangeli > Signed-off-by: Mel Gorman Reviewed-by: Michal Hocko -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/