From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1751216Ab2F2Fbf (ORCPT <rfc822;w@1wt.eu>);
	Fri, 29 Jun 2012 01:31:35 -0400
Received: from e39.co.us.ibm.com ([32.97.110.160]:33908 "EHLO
	e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1750830Ab2F2Fbd (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Fri, 29 Jun 2012 01:31:33 -0400
Message-ID: <1340947838.2293.2.camel@falcor>
Subject: Re: [PATCH 0/4] Was: deferring __fput()
From: Mimi Zohar <zohar@linux.vnet.ibm.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        ". James Morris" <jmorris@namei.org>,
        linux-security-module@vger.kernel.org,
        linux-kernel <linux-kernel@vger.kernel.org>,
        David Howells <dhowells@redhat.com>
Date: Fri, 29 Jun 2012 01:30:38 -0400
In-Reply-To: <20120628043836.GW14083@ZenIV.linux.org.uk>
References: <1340369098.2464.20.camel@falcor>
	 <20120623092049.GH14083@ZenIV.linux.org.uk>
	 <20120623194505.GI14083@ZenIV.linux.org.uk>
	 <20120623203800.GA10306@redhat.com>
	 <20120623210141.GK14083@ZenIV.linux.org.uk>
	 <20120624041652.GN14083@ZenIV.linux.org.uk>
	 <20120624153310.GB24596@redhat.com>
	 <20120625060357.GT14083@ZenIV.linux.org.uk>
	 <20120625151812.GA16062@redhat.com> <20120627183721.GA23086@redhat.com>
	 <20120628043836.GW14083@ZenIV.linux.org.uk>
Content-Type: text/plain; charset="UTF-8"
X-Mailer: Evolution 3.2.3 (3.2.3-3.fc16) 
Content-Transfer-Encoding: 7bit
Mime-Version: 1.0
x-cbid: 12062905-4242-0000-0000-00000229B1C1
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Thu, 2012-06-28 at 05:38 +0100, Al Viro wrote:
> On Wed, Jun 27, 2012 at 08:37:21PM +0200, Oleg Nesterov wrote:
> > On 06/25, Oleg Nesterov wrote:
> > >
> > > And if it always takes ->pi_lock we do not need the new PF_ or something
> > > else, exit_task_work() can set task->task_works = NO_MORE under ->pi_lock
> > > (task_work_run() can check PF_EXITING), and task_work_add() ensures that
> > > task_works != NO_MORE.
> > >
> > > What do you think?
> > 
> > It is not clear to me if you agree or not. So I am simply sending the
> > patches I have.
> > 
> > Feel free to ignore or re-do.
> > 
> > Seriously, why should we add 2 pointers into task_struct? Sure, this
> > is minor, but still... But perhaps task_work.c should not play tricks
> > with the circular list, task_work_run() can reverse the list as you
> > initially suggested.
> > 
> > Also, I am not sure about "define rcu_head callback_head", this series
> > doesn't do this. But again, up to you.
> 
> Umm...  FWIW, my variant circa yesterday is in vfs.git#untested; it seems to survive
> on uml/amd64 at least.  I'll look through your patches and see what can be nicked.
> The list removal logics in mine looks really ugly ;-/

Still failing to boot.  Fails to boot starting with commit "b24dfa6
switch fput to task_work_add".

Mimi