From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932522AbVHZGHz (ORCPT ); Fri, 26 Aug 2005 02:07:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932523AbVHZGHz (ORCPT ); Fri, 26 Aug 2005 02:07:55 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:42217 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S932522AbVHZGHy (ORCPT ); Fri, 26 Aug 2005 02:07:54 -0400 Date: Fri, 26 Aug 2005 08:08:15 +0200 From: Ingo Molnar To: Steven Rostedt Cc: "Stephen C. Tweedie" , LKML Subject: Re: [patch] Real-Time Preemption, -RT-2.6.13-rc4-V0.7.52-01 Message-ID: <20050826060815.GB17783@elte.hu> References: <1123011928.1590.43.camel@localhost.localdomain> <1123025895.25712.7.camel@dhcp153.mvista.com> <1123027226.1590.59.camel@localhost.localdomain> <1123035909.11101.1.camel@c-67-188-6-232.hsd1.ca.comcast.net> <1123036936.1590.69.camel@localhost.localdomain> <1123037933.11101.11.camel@c-67-188-6-232.hsd1.ca.comcast.net> <1123080606.1590.119.camel@localhost.localdomain> <1123087447.1590.136.camel@localhost.localdomain> <20050812125844.GA13357@elte.hu> <1125030249.5365.23.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1125030249.5365.23.camel@localhost.localdomain> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL autolearn=disabled SpamAssassin version=3.0.3 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Steven Rostedt wrote: > So, the only other solutions that I can think of is: > > a) add yet another (bloat) lock to the buffer head. > > b) Still use your b_update_lock for the jbd_lock_bh_journal_head and > change the jbd_lock_bh_state to what I discussed earlier, and that > being the hash wait_on_bit code. could you try a), how clean does it get? Personally i'm much more in favor of cleanliness. On the vanilla kernel a spinlock is zero bytes on UP [the most RAM-sensitive platform], and it's a word on typical SMP. Ingo