From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752458AbaHTJwy (ORCPT ); Wed, 20 Aug 2014 05:52:54 -0400 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:37072 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751258AbaHTJww (ORCPT ); Wed, 20 Aug 2014 05:52:52 -0400 X-Sasl-enc: SDtvOM95qA9XW0uVfWOSFiXDL+pWW9GsvMeXj/yhNCWg 1408528371 Message-ID: <1408528367.11028.44.camel@perseus.themaw.net> Subject: Re: [PATCH 0/5] RCU-walk support for autofs From: Ian Kent To: NeilBrown Cc: autofs@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 20 Aug 2014 17:52:47 +0800 In-Reply-To: <1408506167.11028.32.camel@perseus.themaw.net> References: <20140818062844.9860.43007.stgit@notabene.brown> <1408350340.2533.3.camel@perseus.fritz.box> <1408442547.11314.9.camel@perseus.themaw.net> <20140819211654.5ec3853a@notabene.brown> <1408451815.11314.15.camel@perseus.themaw.net> <20140820131352.2aad3ca5@notabene.brown> <1408506167.11028.32.camel@perseus.themaw.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 (3.10.4-3.fc20) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2014-08-20 at 11:42 +0800, Ian Kent wrote: > Great minds think alike. > I have basically the exact same patch and I'm testing now. > It probably should be folded into "autofs4: avoid taking fs_lock during > rcu-walk". > > It takes ages though, the test has two configurations to test and each > one takes about 70 minutes. > > fyi, my criteria for the test is if it runs through to completion once > then that's essentially a pass. If not then there is a race that needs > to be fixed before merge. If it fails on runs two or three then there's > a hard to find race that needs attention but is not serious enough to > block merging. I usually stop after three runs but if fails are seen > later then, they too need to be resolved in the fullness of time. > > The reason for this is that in heavy use sites we rarely see more than > about three processes concurrently accessing mount points and the test > run uses 10 client instances (currently on a 6 CPU machine) that all > access the mount tree at the same time so that should be somewhat more > pressure than is seen under heavy use. > > And indeed this rule of has proven reliable so far. I've run my test three times now. The first time I had debug logging enabled. I disabled it for the second and third runs as that sometimes makes a difference. All three runs went through fine. The only thing I noticed was that the test took a little longer (two and a half to three minutes longer, of 70) to complete than without the patch series but I've seen that sort of variation in kernels at different times in the past. So I think the series is fine and should be merged. Please feel free to add any of my acked, reviewed and tested by to them. Ian