From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753833AbaGSXp4 (ORCPT ); Sat, 19 Jul 2014 19:45:56 -0400 Received: from mail-pa0-f47.google.com ([209.85.220.47]:60351 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752064AbaGSXpx (ORCPT ); Sat, 19 Jul 2014 19:45:53 -0400 Date: Sat, 19 Jul 2014 16:44:15 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Sasha Levin , Andrew Morton cc: Vlastimil Babka , Hugh Dickins , Konstantin Khlebnikov , Johannes Weiner , Michel Lespinasse , Lukas Czerner , Dave Jones , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] shmem: fix faulting into a hole while it's punched, take 3 In-Reply-To: <53C8FAA6.9050908@oracle.com> Message-ID: References: <53C7F55B.8030307@suse.cz> <53C7F5FF.7010006@oracle.com> <53C8FAA6.9050908@oracle.com> User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 18 Jul 2014, Sasha Levin wrote: > On 07/17/2014 12:12 PM, Sasha Levin wrote: > > On 07/17/2014 12:10 PM, Vlastimil Babka wrote: > >> > On 07/15/2014 12:28 PM, Hugh Dickins wrote: > >>> >> In the end I decided that we had better look at it as two problems, > >>> >> the trinity faulting starvation, and the indefinite punching loop, > >>> >> so 1/2 and 2/2 present both solutions: belt and braces. > >> > > >> > I tested that with my reproducer and it was OK, but as I already said, it's not trinity so I didn't observe the new problems in the first place. > > I've started seeing a new hang in the lru code, but I'm not sure if > > it's related to this patch or not (the locks are the same ones, but > > the location is very different). > > > > I'm looking into that. > > Hi Hugh, > > The new hang I'm seeing is much simpler to analyse (compared to shmem_fallocate) and > doesn't seem to be related. I'll send a separate mail and Cc you just in case, but > I don't think that this patchset has anything to do with it. Thanks for testing and following up, Sasha. I agree, that one is unrelated. I've just sent a suggestion in your lru_add_drain_all thread. > > Otherwise, I've been unable to reproduce the shmem_fallocate hang. Great. Andrew, I think we can say that it's now safe to send 1/2 shmem: fix faulting into a hole, not taking i_mutex 2/2 shmem: fix splicing from a hole while it's punched on to Linus whenever suits you. (You have some other patches in the mainline-later section of the mmotm/series file: they're okay too, but not in doubt as these two were.) Thanks, Hugh