From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757169Ab1IAJ7c (ORCPT ); Thu, 1 Sep 2011 05:59:32 -0400 Received: from www.linutronix.de ([62.245.132.108]:43721 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756087Ab1IAJ7a (ORCPT ); Thu, 1 Sep 2011 05:59:30 -0400 Date: Thu, 1 Sep 2011 11:59:18 +0200 (CEST) From: Thomas Gleixner To: Shan Hai cc: akpm@linux-foundation.org, eric.dumazet@gmail.com, vapier@gentoo.org, asharma@fb.com, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org Subject: Re: [PATCH V2 1/1] lib/atomic64 using raw_spin_lock_irq[save|resotre] for atomicity In-Reply-To: <1314847923-26428-2-git-send-email-haishan.bai@gmail.com> Message-ID: References: <1314847923-26428-1-git-send-email-haishan.bai@gmail.com> <1314847923-26428-2-git-send-email-haishan.bai@gmail.com> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 1 Sep 2011, Shan Hai wrote: > The spin_lock_irq[save|restore] could break the atomicity of the > atomic64_* operations in the PREEMPT-RT configuration, because > the spin_lock_irq[save|restore] themselves are preemptable in the > PREEMPT-RT, using raw variant of the spin lock could provide the > atomicity that atomic64_* need. Good catch. Queued for the next release. Thanks, tglx