Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 29 Jan 2003 03:31:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 29 Jan 2003 03:31:59 -0500 Received: from packet.digeo.com ([12.110.80.53]:61430 "EHLO packet.digeo.com") by vger.kernel.org with ESMTP id ; Wed, 29 Jan 2003 03:31:57 -0500 Date: Wed, 29 Jan 2003 00:41:33 -0800 From: Andrew Morton To: Anton Blanchard Cc: shemminger@osdl.org, torvalds@transmeta.com, andrea@suse.de, ak@suse.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH] (1/4) 2.5.59 fast reader/writer lock for gettimeofday Message-Id: <20030129004133.33de30a8.akpm@digeo.com> In-Reply-To: <20030129072622.GA18250@krispykreme> References: <1043797341.10150.300.camel@dell_ss3.pdx.osdl.net> <20030128230639.A17385@twiddle.net> <20030129072622.GA18250@krispykreme> X-Mailer: Sylpheed version 0.8.9 (GTK+ 1.2.10; i586-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 29 Jan 2003 08:41:11.0963 (UTC) FILETIME=[2D471EB0:01C2C772] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Anton Blanchard wrote: > > > > These need to be mb(), not wmb(), if you want the bits in between > > to actually happen in between, as with your xtime example. At > > present there's nothing stoping xtime from being *read* before > > your read from pre_sequence happens. > > But with frlocks we synchronise writers with a spinlock, so shouldnt it > provide that synchronisation? > Richard is referring to the new fr_write_begin/end code, which doesn't take a spinlock because it assumes that writer serialisation has been provided by external means. - 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/