Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751058AbVJFOxM (ORCPT ); Thu, 6 Oct 2005 10:53:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751060AbVJFOxM (ORCPT ); Thu, 6 Oct 2005 10:53:12 -0400 Received: from smtp.osdl.org ([65.172.181.4]:7360 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751056AbVJFOxL (ORCPT ); Thu, 6 Oct 2005 10:53:11 -0400 Date: Thu, 6 Oct 2005 07:52:17 -0700 (PDT) From: Linus Torvalds To: Andrey Savochkin cc: Andi Kleen , Kirill Korotaev , linux-kernel@vger.kernel.org, Andrew Morton , xemul@sw.ru, st@sw.ru, discuss@x86-64.org Subject: Re: SMP syncronization on AMD processors (broken?) In-Reply-To: <20051006174604.B10342@castle.nmd.msu.ru> Message-ID: References: <434520FF.8050100@sw.ru> <20051006174604.B10342@castle.nmd.msu.ru> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 802 Lines: 23 On Thu, 6 Oct 2005, Andrey Savochkin wrote: > > Well, it's hard to swallow... > It's not about being not fully fair, it's about deadlocks that started > to appear after code changes inside retry loops... No, it's not about fairness. It's about BUGS IN YOUR CODE. If you need fairness, you need to implement that yourself. You can do so many ways. Either on top of spinlocks, by using an external side-band channel, or by using semaphores instead of spinlocks (semaphores are much higher cost, but part of the cost is that they _are_ fair). Linus - 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/