From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755513Ab1GQBEb (ORCPT ); Sat, 16 Jul 2011 21:04:31 -0400 Received: from palinux.external.hp.com ([192.25.206.14]:45691 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754700Ab1GQBEa (ORCPT ); Sat, 16 Jul 2011 21:04:30 -0400 Date: Sat, 16 Jul 2011 19:04:28 -0600 From: Matthew Wilcox To: Anton Blanchard Cc: npiggin@kernel.dk, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andi Kleen , Tim Chen Subject: Re: vfsmount lock issues on very large ppc64 box Message-ID: <20110717010427.GC5359@parisc-linux.org> References: <20110717105027.53cc3ca4@kryten> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110717105027.53cc3ca4@kryten> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jul 17, 2011 at 10:50:27AM +1000, Anton Blanchard wrote: > Looking closer, all of these calls are in pipefs and sockfs. > Since we never mount either filesystem they never get a long term > reference and we always end up in the very slow write brlock path > that takes a lock for each online CPU. > > Here is a quick hack that takes a long term reference on pipefs > and sockfs which fixes the problem. Any thoughts on how we should > fix it properly? I know Tim and Andi have been looking into this ... I forget what their fix was though. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."