From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754338Ab2BTVaA (ORCPT ); Mon, 20 Feb 2012 16:30:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42697 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753911Ab2BTV37 (ORCPT ); Mon, 20 Feb 2012 16:29:59 -0500 Date: Mon, 20 Feb 2012 22:29:55 +0100 From: Andrea Arcangeli To: Dean Nelson Cc: linux-mm@kvack.org, Jin Dongming , linux-kernel@vger.kernel.org Subject: Re: [PATCH] thp: allow a hwpoisoned head page to be put back to LRU Message-ID: <20120220212955.GD10222@redhat.com> References: <20120220211040.8887.22420.email-sent-by-dnelson@aqua> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120220211040.8887.22420.email-sent-by-dnelson@aqua> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 20, 2012 at 04:10:40PM -0500, Dean Nelson wrote: > Andrea Arcangeli pointed out to me that a check in __memory_failure() which > was intended to prevent THP tail pages from being checked for the absence > of the PG_lru flag (something that is always the case), was also preventing > THP head pages from being checked. > > A THP head page could actually benefit from the call to shake_page() by > ending up being put back to a LRU, provided it had been waiting in a > pagevec array. > > Andrea suggested that the "!PageTransCompound(p)" in the if-statement > should be replaced by a "!PageTransTail(p)", thus allowing THP head pages > to be checked and possibly shaken. > > Signed-off-by: Dean Nelson Reviewed-by: Andrea Arcangeli