Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758053AbYH2RGs (ORCPT ); Fri, 29 Aug 2008 13:06:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758078AbYH2RGL (ORCPT ); Fri, 29 Aug 2008 13:06:11 -0400 Received: from one.firstfloor.org ([213.235.205.2]:54892 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757519AbYH2RGK (ORCPT ); Fri, 29 Aug 2008 13:06:10 -0400 Date: Fri, 29 Aug 2008 19:08:51 +0200 From: Andi Kleen To: Gregory Haskins Cc: Andi Kleen , Gregory Haskins , mingo@elte.hu, rostedt@goodmis.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org Subject: Re: [PATCH] seqlock: serialize against writers Message-ID: <20080829170851.GZ26610@one.firstfloor.org> References: <20080829154237.1196.66825.stgit@dev.haskins.net> <87abevpzv7.fsf@basil.nowhere.org> <48B81F60.3080409@gmail.com> <20080829162216.GW26610@one.firstfloor.org> <48B823F6.1010509@novell.com> <20080829163749.GX26610@one.firstfloor.org> <48B826BD.9000308@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48B826BD.9000308@novell.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 646 Lines: 18 No idea on the problem itself because I don't understand it, just: > Given that, we either need to address the const requirement > for userspace, alter userspace's usage, or find another way to address > the deadlock. Any ideas? In the worst case you can always disable the vsyscall gtod() and thus the need for a user space safe seqlock_t, but it will hurt some workloads significantly. -Andi -- 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/