From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932514AbWALR4u (ORCPT ); Thu, 12 Jan 2006 12:56:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932523AbWALR4u (ORCPT ); Thu, 12 Jan 2006 12:56:50 -0500 Received: from liaag2aa.mx.compuserve.com ([149.174.40.154]:37287 "EHLO liaag2aa.mx.compuserve.com") by vger.kernel.org with ESMTP id S932514AbWALR4t (ORCPT ); Thu, 12 Jan 2006 12:56:49 -0500 Date: Thu, 12 Jan 2006 12:53:08 -0500 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: Re: [patch] fix i386 mutex fastpath on FRAME_POINTER && !DEBUG_MUTEXES To: Ingo Molnar Cc: linux-kernel , Linus Torvalds , Hugh Dickins , Ingo Molnar Message-ID: <200601121256_MC3-1-B5C3-FDE0@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In-Reply-To: On Wed, 11 Jan 2006, Ingo Molnar wrote: > On Wed, 11 Jan 2006, Chuck Ebbert wrote: > > > > > LOCK " decl (%%eax) \n" \ > > " jns 1f \n" \ > > " call "#fail_fn" \n" \ > > "1: \n" \ > > \ > > :"=a" (dummy) \ > > : "a" (count) \ > > > > > > Will the extra taken forward conditional jump in the fastpath cause much > > of a slowdown? > > yeah - the fastpath is much more common than the slowpath. But that's how the spinlock code does it. Should that be changed to put the spinloops in .text.lock and make the fastpaths a fall-through? -- Chuck Currently reading: _Olympos_ by Dan Simmons