Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756009Ab2JJRvP (ORCPT ); Wed, 10 Oct 2012 13:51:15 -0400 Received: from casper.infradead.org ([85.118.1.10]:47259 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750948Ab2JJRvO convert rfc822-to-8bit (ORCPT ); Wed, 10 Oct 2012 13:51:14 -0400 Message-ID: <1349891458.1279.23.camel@twins> Subject: Re: [PATCH V2] task_work: avoid unneeded cmpxchg() in task_work_run() From: Peter Zijlstra To: Oleg Nesterov Cc: Lai Jiangshan , LKML , Al Viro , Ingo Molnar , Eric Dumazet Date: Wed, 10 Oct 2012 19:50:58 +0200 In-Reply-To: <20121010175032.GA22642@redhat.com> References: <50729A78.9090601@cn.fujitsu.com> <20121008123815.GA847@redhat.com> <1349780697.7880.14.camel@twins> <5075098E.9090808@cn.fujitsu.com> <20121010175032.GA22642@redhat.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 511 Lines: 12 On Wed, 2012-10-10 at 19:50 +0200, Oleg Nesterov wrote: > > But you did not answer, and I am curious. What was your original > motivation? Is xchg really faster than cmpxchg? And is this true over multiple architectures? Or are we optimizing for x86_64 (again) ? -- 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/