From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f175.google.com (mail-wi0-f175.google.com [209.85.212.175]) by kanga.kvack.org (Postfix) with ESMTP id 5BAB56B00BF for ; Tue, 4 Nov 2014 07:30:24 -0500 (EST) Received: by mail-wi0-f175.google.com with SMTP id ex7so9236034wid.14 for ; Tue, 04 Nov 2014 04:30:23 -0800 (PST) Received: from jenni1.inet.fi (mta-out1.inet.fi. [62.71.2.234]) by mx.google.com with ESMTP id jb20si12169253wic.97.2014.11.04.04.30.23 for ; Tue, 04 Nov 2014 04:30:23 -0800 (PST) Date: Tue, 4 Nov 2014 14:30:21 +0200 From: "Kirill A. Shutemov" Subject: Re: [PATCH] mremap: take anon_vma lock in shared mode Message-ID: <20141104123021.GB28274@node.dhcp.inet.fi> References: <1414507237-114852-1-git-send-email-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins , akpm@linux-foundation.org Cc: "Kirill A. Shutemov" , riel@redhat.com, walken@google.com, aarcange@redhat.com, linux-mm@kvack.org On Mon, Nov 03, 2014 at 10:08:31PM -0800, Hugh Dickins wrote: > On Tue, 28 Oct 2014, Kirill A. Shutemov wrote: > > > There's no modification to anon_vma interval tree. We only need to > > serialize against exclusive rmap walker who want s to catch all ptes the > > page is mapped with. Shared lock is enough for that. > > > > Suggested-by: Davidlohr Bueso > > Signed-off-by: Kirill A. Shutemov > > NAK: please read Michel's comment on need_rmap_locks again, there is > no point in using read locks on anon_vma (and i_mmap) here, those will > not exclude the read locks on anon_vma (and i_mmap) in the rmap walk, > while we move ptes around. > > Or am I confused? Andrew, please drop the patch. -- Kirill A. Shutemov -- 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