From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e6.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m1KEsdTB012647 for ; Wed, 20 Feb 2008 09:54:39 -0500 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m1KEqgv6234012 for ; Wed, 20 Feb 2008 09:52:42 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m1KEqgiD015177 for ; Wed, 20 Feb 2008 09:52:42 -0500 Subject: Re: [PATCH] hugetlb: ensure we do not reference a surplus page after handing it to buddy From: Adam Litke In-Reply-To: <20080219153037.ec336fd2.akpm@linux-foundation.org> References: <1203445688.0@pinky> <1203446512.11987.36.camel@localhost.localdomain> <20080219153037.ec336fd2.akpm@linux-foundation.org> Content-Type: text/plain Date: Wed, 20 Feb 2008 08:59:34 -0600 Message-Id: <1203519574.11987.67.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Andy Whitcroft , Nishanth Aravamudan , William Irwin , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Tue, 2008-02-19 at 15:30 -0800, Andrew Morton wrote: > On Tue, 19 Feb 2008 12:41:51 -0600 Adam Litke wrote: > > > Indeed. I'll take credit for this thinko... > > > > On Tue, 2008-02-19 at 18:28 +0000, Andy Whitcroft wrote: > > > When we free a page via free_huge_page and we detect that we are in > > > surplus the page will be returned to the buddy. After this we no longer > > > own the page. However at the end free_huge_page we clear out our mapping > > > pointer from page private. Even where the page is not a surplus we > > > free the page to the hugepage pool, drop the pool locks and then clear > > > page private. In either case the page may have been reallocated. BAD. > > > > > > Make sure we clear out page private before we free the page. > > > > > > Signed-off-by: Andy Whitcroft > > > > Acked-by: Adam Litke > > Was I right to assume that this is also needed in 2.6.24.x? Yep. Thanks Andrew. -- Adam Litke - (agl at us.ibm.com) IBM Linux Technology Center -- 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