Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263905AbTEOJ14 (ORCPT ); Thu, 15 May 2003 05:27:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263911AbTEOJ14 (ORCPT ); Thu, 15 May 2003 05:27:56 -0400 Received: from ppp-217-133-42-200.cust-adsl.tiscali.it ([217.133.42.200]:46471 "EHLO dualathlon.random") by vger.kernel.org with ESMTP id S263905AbTEOJ1x (ORCPT ); Thu, 15 May 2003 05:27:53 -0400 Date: Thu, 15 May 2003 11:40:41 +0200 From: Andrea Arcangeli To: Andrew Morton Cc: dmccr@us.ibm.com, mika.penttila@kolumbus.fi, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: Race between vmtruncate and mapped areas? Message-ID: <20030515094041.GA1429@dualathlon.random> References: <154080000.1052858685@baldur.austin.ibm.com> <20030513181018.4cbff906.akpm@digeo.com> <18240000.1052924530@baldur.austin.ibm.com> <20030514103421.197f177a.akpm@digeo.com> <82240000.1052934152@baldur.austin.ibm.com> <20030515004915.GR1429@dualathlon.random> <20030515013245.58bcaf8f.akpm@digeo.com> <20030515085519.GV1429@dualathlon.random> <20030515022000.0eb9db29.akpm@digeo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030515022000.0eb9db29.akpm@digeo.com> User-Agent: Mutt/1.4i X-GPG-Key: 1024D/68B9CB43 X-PGP-Key: 1024R/CB4660B9 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1148 Lines: 28 On Thu, May 15, 2003 at 02:20:00AM -0700, Andrew Morton wrote: > Andrea Arcangeli wrote: > > > > and it's still racy > > damn, and it just booted ;) > > I'm just a little bit concerned over the ever-expanding inode. Do you > think the dual sequence numbers can be replaced by a single generation > counter? yes, I wrote it as a single counter first, but was unreadable and it had more branches, so I added the other sequence number to make it cleaner. I don't mind another 4 bytes, that cacheline should be hot anyways. > I do think that we should push the revalidate operation over into the vm_ops. > That'll require an extra arg to ->nopage, but it has a spare one anyway (!). not sure why you need a callback, the lowlevel if needed can serialize using the same locking in the address space that vmtruncate uses. I would wait a real case need before adding a callback. Andrea - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/