Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755913Ab1FGPMw (ORCPT ); Tue, 7 Jun 2011 11:12:52 -0400 Received: from mail-pw0-f46.google.com ([209.85.160.46]:54609 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752048Ab1FGPMv (ORCPT ); Tue, 7 Jun 2011 11:12:51 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=P9m4BMOEu7ect4A2q3xdlyqoH1Wb4PfF/NEftVHpBUlJ+0SnC9j91NKllT4c6kTN5b hixZGBCrMQEZx0BhpGavKkIGWdcgPMIoYnJlrXO3IGjecQyv8Ni+NDq7T3rOrxCrjUNR xS62tf8UEVdW1n9KqJobFOWe6fu4769jgRqA8= Date: Wed, 8 Jun 2011 00:12:42 +0900 From: Minchan Kim To: Mel Gorman Cc: Andrew Morton , Andrea Arcangeli , 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: <20110607151242.GI1686@barrios-laptop> 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/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 829 Lines: 22 On Tue, Jun 07, 2011 at 04:07:03PM +0100, 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: Minchan Kim -- Kind regards Minchan Kim -- 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/