From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755762Ab2JQJvq (ORCPT ); Wed, 17 Oct 2012 05:51:46 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:42559 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752101Ab2JQJvo (ORCPT ); Wed, 17 Oct 2012 05:51:44 -0400 Date: Wed, 17 Oct 2012 10:56:35 +0100 From: Alan Cox To: Linus Torvalds Cc: Mikulas Patocka , Jens Axboe , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [PATCH] percpu-rwsem: use barrier in unlock path Message-ID: <20121017105635.7623af47@pyramind.ukuu.org.uk> In-Reply-To: References: X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > a later stores, and stores are viewed in program order, so all x86 > stores have "release consistency" modulo the theoretical PPro bugs > (that I don't think we actually ever saw in practice). We did seem the for real. The PPro is on its way out however so I hardly thing we care about optimising for that case. Alan