From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Subject: Re: [patch 00/27] [rfc] vfs scalability patchset Date: Thu, 30 Apr 2009 08:14:54 +0200 Message-ID: <20090430061454.GE23746@wotan.suse.de> References: <20090425012020.457460929@suse.de> <20090425041829.GX8633@ZenIV.linux.org.uk> <20090425080143.GA29033@infradead.org> <20090425080649.GA8633@ZenIV.linux.org.uk> <20090428090930.GA14638@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , Al Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Zijlstra To: "Eric W. Biederman" Return-path: Received: from cantor2.suse.de ([195.135.220.15]:39955 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753416AbZD3GOz (ORCPT ); Thu, 30 Apr 2009 02:14:55 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, Apr 28, 2009 at 04:32:13AM -0700, Eric W. Biederman wrote: > Christoph Hellwig writes: > > > 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. > > The plan is to post my updated patches tomorrow after I have slept. > > What I am looking at is that the tty layer is not a special case. Any > subsystem that wants any revoke kind of functionality starts wanting > the list of files that are open. My current list where we have > something like this is: sysfs, proc, sysctl, tun, tty, sound. How's this coming along? It would be good to get this change out and reviewed ASAP, and ahead of the rest of your patchset IMO. Hopefully we can get it into Al's tree for 2.6.31 if it all falls out nicely. BTW. I would just keep the single files_lock spinlock in the first patch that would move to per-inode lists, and then a 2nd patch could swap out the locking without making any other changes (or else you could just leave the locking global and we can evaluate it in the context of the rest of the vfs scalability work).