From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f54.google.com (mail-qg0-f54.google.com [209.85.192.54]) by kanga.kvack.org (Postfix) with ESMTP id 92A1E6B0036 for ; Fri, 9 May 2014 04:44:45 -0400 (EDT) Received: by mail-qg0-f54.google.com with SMTP id q108so4025372qgd.41 for ; Fri, 09 May 2014 01:44:45 -0700 (PDT) Received: from mail-qa0-x230.google.com (mail-qa0-x230.google.com [2607:f8b0:400d:c00::230]) by mx.google.com with ESMTPS id l110si1740556qgf.59.2014.05.09.01.44.44 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 09 May 2014 01:44:45 -0700 (PDT) Received: by mail-qa0-f48.google.com with SMTP id i13so3732022qae.21 for ; Fri, 09 May 2014 01:44:43 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20140508181416.GN19914@cmpxchg.org> References: <1399328011-15317-1-git-send-email-kirill.shutemov@linux.intel.com> <20140506130655.GE19914@cmpxchg.org> <20140508181416.GN19914@cmpxchg.org> Date: Fri, 9 May 2014 01:44:43 -0700 Message-ID: Subject: Re: [PATCH] mm, thp: close race between mremap() and split_huge_page() From: Michel Lespinasse Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: "Kirill A. Shutemov" , Andrew Morton , linux-mm@kvack.org, Andrea Arcangeli , Rik van Riel , Dave Jones , stable@vger.kernel.org On Thu, May 8, 2014 at 11:14 AM, Johannes Weiner wrote: > On Wed, May 07, 2014 at 05:13:32PM -0700, Michel Lespinasse wrote: >> On Tue, May 6, 2014 at 6:06 AM, Johannes Weiner wrote: >> > Fixes: 108d6642ad81 ("mm anon rmap: remove anon_vma_moveto_tail") >> >> I think 108d6642ad81 on its own was OK (as it always took the locks); >> but the attempt to not take them in the common case in 38a76013ad80 is >> where I forgot to consider the THP case. > > 108d6642ad81 replaced the chain ordering with an explicit lock, but I > see the unconditional locking only in move_ptes(), which isn't called > for THP pmds. Ah yes, you are right. -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies. -- 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