From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [Lsf10-pc] Current MM topics for LSF10/MM Summit 8-9 August in Boston Date: Mon, 21 Jun 2010 17:31:41 +0300 Message-ID: <4C1F77CD.40509@redhat.com> References: <1276721459.2847.399.camel@mulgrave.site> <20100621120526.GA31679@laptop> <20100621131608.GW5787@random.random> <20100621132238.GK4689@redhat.com> <20100621140939.GY5787@random.random> <20100621141855.GN4689@redhat.com> <20100621142952.GZ5787@random.random> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , Nick Piggin , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, lsf10-pc@lists.linuxfoundation.org, linux-scsi@vger.kernel.org To: Andrea Arcangeli Return-path: Received: from mx1.redhat.com ([209.132.183.28]:8483 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757962Ab0FUObr (ORCPT ); Mon, 21 Jun 2010 10:31:47 -0400 In-Reply-To: <20100621142952.GZ5787@random.random> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 06/21/2010 05:29 PM, Andrea Arcangeli wrote: > On Mon, Jun 21, 2010 at 05:18:56PM +0300, Gleb Natapov wrote: > >> Avi did the fix. We discussed using MADV_DONTFORK for that, but calling >> madvise() from kernel deemed to be messy. >> > Agree that calling madvise looks messy. It's possible to set > VM_DONTCOPY under mmap_sem write mode and it'll work as well. > But we aren't guaranteed to get our own vma, yes? > But surely we can as well keep this quicker fix until the fork vs gup > race is fixed, and back it out later. > Right. Note kvm shouldn't be calling do_mmap() in any case. I let that in because it was simple and because we had a userspace interface relying on that, but that's no longer the case, so I'll make that page kernel owned. -- error compiling committee.c: too many arguments to function