From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [patch 00/27] [rfc] vfs scalability patchset Date: Tue, 28 Apr 2009 05:09:30 -0400 Message-ID: <20090428090930.GA14638@infradead.org> References: <20090425012020.457460929@suse.de> <20090425041829.GX8633@ZenIV.linux.org.uk> <20090425080143.GA29033@infradead.org> <20090425080649.GA8633@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , npiggin@suse.de, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Zijlstra To: Al Viro Return-path: Received: from bombadil.infradead.org ([18.85.46.34]:60386 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753931AbZD1JJf (ORCPT ); Tue, 28 Apr 2009 05:09:35 -0400 Content-Disposition: inline In-Reply-To: <20090425080649.GA8633@ZenIV.linux.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Sat, Apr 25, 2009 at 09:06:49AM +0100, Al Viro wrote: > Maybe... What Eric proposed is essentially a reuse of s_list for per-inode > list of struct file. Presumably with something like i_lock for protection. > So that's not a conflict. But what do we actually want it for? Right now it's only used for ttys, which Nick has split out, and for remount r/o. For the normal remount r/o case it will go away once we have proper per-sb writer counts. And the fource remount r/o from sysrq is completely broken. A while ago Peter had patches for files_lock scalability that went even further than Nicks, and if I remember the arguments correctly just splitting the lock wasn't really enough and he required additional batching because there just were too many lock roundtrips. (Peter, do you remember the defails?)