From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753677Ab0F3ILi (ORCPT ); Wed, 30 Jun 2010 04:11:38 -0400 Received: from casper.infradead.org ([85.118.1.10]:36238 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752252Ab0F3ILg convert rfc822-to-8bit (ORCPT ); Wed, 30 Jun 2010 04:11:36 -0400 Subject: Re: [PATCH 4/4, v2] x86: enlightenment for ticket spin locks - improve yield behavior on Xen From: Peter Zijlstra To: Jan Beulich Cc: mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com, jeremy.fitzhardinge@citrix.com, Ky Srinivasan , linux-kernel@vger.kernel.org In-Reply-To: <4C2A20E30200007800008A17@vpn.id2.novell.com> References: <4C2A20E30200007800008A17@vpn.id2.novell.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Wed, 30 Jun 2010 10:11:25 +0200 Message-ID: <1277885485.1868.74.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2010-06-29 at 15:35 +0100, Jan Beulich wrote: > > The (only) additional overhead this introduces for native execution is > the writing of the owning CPU in the lock acquire paths. Uhm, and growing the size of spinlock_t to 6 (or 8 bytes when aligned) bytes when NR_CPUS>256.