Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754751Ab0AERZj (ORCPT ); Tue, 5 Jan 2010 12:25:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753978Ab0AERZi (ORCPT ); Tue, 5 Jan 2010 12:25:38 -0500 Received: from one.firstfloor.org ([213.235.205.2]:42924 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754214Ab0AERZi (ORCPT ); Tue, 5 Jan 2010 12:25:38 -0500 To: Linus Torvalds Cc: KAMEZAWA Hiroyuki , Minchan Kim , Peter Zijlstra , "Paul E. McKenney" , Peter Zijlstra , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , cl@linux-foundation.org, "hugh.dickins" , Nick Piggin , Ingo Molnar Subject: Re: [RFC][PATCH 6/8] mm: handle_speculative_fault() From: Andi Kleen References: <20100104182429.833180340@chello.nl> <20100104182813.753545361@chello.nl> <20100105092559.1de8b613.kamezawa.hiroyu@jp.fujitsu.com> <28c262361001042029w4b95f226lf54a3ed6a4291a3b@mail.gmail.com> <20100105134357.4bfb4951.kamezawa.hiroyu@jp.fujitsu.com> <20100105143046.73938ea2.kamezawa.hiroyu@jp.fujitsu.com> <20100105163939.a3f146fb.kamezawa.hiroyu@jp.fujitsu.com> Date: Tue, 05 Jan 2010 18:25:32 +0100 In-Reply-To: (Linus Torvalds's message of "Tue, 5 Jan 2010 08:14:51 -0800 (PST)") Message-ID: <87wrzwbh0z.fsf@basil.nowhere.org> User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/22.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 853 Lines: 23 Linus Torvalds writes: > > etc, because the x86-64 code has obviously never seen the optimized > call-paths, and they need the asm wrappers for full semantics. iirc Andrea ran benchmarks at some point and it didn't make too much difference on the systems back then (K8 era). Given K8 has fast atomics. > Oh well. Somebody who is bored might look at trying to make the wrapper > code in arch/x86/lib/semaphore_32.S work on x86-64 too. It should make the > successful rwsem cases much faster. Maybe, maybe not. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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/