From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263295AbTFTQXz (ORCPT ); Fri, 20 Jun 2003 12:23:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263298AbTFTQXz (ORCPT ); Fri, 20 Jun 2003 12:23:55 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:13472 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S263295AbTFTQXy (ORCPT ); Fri, 20 Jun 2003 12:23:54 -0400 Date: Fri, 20 Jun 2003 17:37:55 +0100 From: viro@parcelfarce.linux.theplanet.co.uk To: David Howells Cc: Linus Torvalds , Kernel Mailing List Subject: Re: [PATCH] VFS autmounter support v3 Message-ID: <20030620163755.GH6754@parcelfarce.linux.theplanet.co.uk> References: <25482.1056125836@warthog.warthog> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <25482.1056125836@warthog.warthog> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 20, 2003 at 05:17:16PM +0100, David Howells wrote: > (2) Automatic mount point expiry. This allows any mountpoint to be given a > timeout, such that when mntput() detects that the vfsmount is only used > by its parent, a work chitty will be enqueued to cause the containing > namespace to be vacuumed later for dead mounts. Broken. a) it doesn't scale. A single expirable mountpoint and we will be walking potentially very long list. b) the logics is wrong - you are scheduling "let's go and expire stuff" when ->mnt_count drops far enough; put something like /usr/share on a separate fs and observe what happens to ->mnt_count. It will touch the trigger value very often. Better yet, do that with /usr/include and start a big build. You will have your expiry code triggered all the time, even though fs is in very active use.