Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1424376AbWLBSsY (ORCPT ); Sat, 2 Dec 2006 13:48:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1424370AbWLBSsY (ORCPT ); Sat, 2 Dec 2006 13:48:24 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:47549 "EHLO ZenIV.linux.org.uk") by vger.kernel.org with ESMTP id S1424349AbWLBSsX (ORCPT ); Sat, 2 Dec 2006 13:48:23 -0500 Date: Sat, 2 Dec 2006 18:48:21 +0000 From: Al Viro To: Thomas Gleixner Cc: Matthew Wilcox , Linus Torvalds , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] timers, pointers to functions and type safety Message-ID: <20061202184821.GM3078@ftp.linux.org.uk> References: <20061201172149.GC3078@ftp.linux.org.uk> <1165064370.24604.36.camel@localhost.localdomain> <20061202140521.GJ3078@ftp.linux.org.uk> <1165070713.24604.50.camel@localhost.localdomain> <20061202160252.GQ14076@parisc-linux.org> <1165082803.24604.54.camel@localhost.localdomain> <20061202181957.GK3078@ftp.linux.org.uk> <1165084076.24604.56.camel@localhost.localdomain> <20061202184035.GL3078@ftp.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061202184035.GL3078@ftp.linux.org.uk> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1379 Lines: 38 On Sat, Dec 02, 2006 at 06:40:35PM +0000, Al Viro wrote: > On Sat, Dec 02, 2006 at 07:27:56PM +0100, Thomas Gleixner wrote: > > On Sat, 2006-12-02 at 18:19 +0000, Al Viro wrote: > > > > This is going to make a lot of data structures smaller, when the > > > > timer_list is embedded in the structure itself and for the lot, which > > > > ignores the timer callback argument anyway. > > > > > > container_of => still lousy type safety. All over the sodding place. > > > > Not less than timer->data, where timer data is void * > > RTFPosting. It might be void *, but it's set via SETUP_TIMER which > does type checks before casting to void *. > > IOW, I don't want _any_ typecasts/container_of necessary in the code. > > Sane variant is > > void foo_timer(struct net_device *dev) > { > ... > } > > struct foo_dev *p = netdev_priv(dev); > SETUP_TIMER(&p->timer, foo_timer, dev); > > etc. > > With warning generated if foo_timer(dev) would not be type safe. Without > typecasts. Without container_of(). Without any bleeding cruft at all. BTW, the same goes for tasklets and for work_struct. Separate series, obviously... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/