From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761315AbYFTU6y (ORCPT ); Fri, 20 Jun 2008 16:58:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756230AbYFTU6q (ORCPT ); Fri, 20 Jun 2008 16:58:46 -0400 Received: from casper.infradead.org ([85.118.1.10]:40945 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752889AbYFTU6p (ORCPT ); Fri, 20 Jun 2008 16:58:45 -0400 Date: Fri, 20 Jun 2008 13:58:40 -0700 From: Arjan van de Ven To: Jonathan Corbet Cc: LKML , Linus Torvalds , Andi Kleen , Alan Cox , Al Viro Subject: Re: [PATCH, RFC] fasync() BKL pushdown Message-ID: <20080620135840.562dd4a5@infradead.org> In-Reply-To: <20080620112914.783be428@bike.lwn.net> References: <20080620112914.783be428@bike.lwn.net> Organization: Intel X-Mailer: Claws Mail 3.3.1 (GTK+ 2.12.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 20 Jun 2008 11:29:14 -0600 Jonathan Corbet wrote: > > The majority of fasync() functions just call fasync_helper() with a > pointer to an fasync_struct reachable from the file structure. Given > that (1) the struct file will not go away while fasync() is running, > and (2) the VFS-level fasync() stuff is protected with the Big Fasync > Lock, I contend that these simple implementations have no need for > the BKL. Once those are filtered out, there's really only a > half-dozen places which need to be fixed. > Jonathan Corbet (7): > mpt: fasync BKL pushdown > i2o: fasync BKL pushdown > tun: fasync BKL pushdown > tty_io: fasync BKL pushdown > Bluetooth VHCI: fasync BKL pushdown > ecryptfs: fasync BKL pushdown > Call fasync() functions without the BKL > > And the actual patch is appended. If nobody objects, I'll pull these > into the bkl-removal tree shortly. > looks good to me only question is if this one is really needed: + lock_kernel(); tty = (struct tty_struct *)filp->private_data; if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) - return 0; + goto out; retval = fasync_helper(fd, filp, on, &tty->fasync); if (retval <= 0) (given that it just calls the helper.. mostly and that Alan has been busy removing the BKL from the tty layer) -- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org