Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755798AbaFBQaw (ORCPT ); Mon, 2 Jun 2014 12:30:52 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:49917 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753536AbaFBQav (ORCPT ); Mon, 2 Jun 2014 12:30:51 -0400 Date: Mon, 2 Jun 2014 18:30:32 +0200 From: Peter Zijlstra To: Mikulas Patocka Cc: Linus Torvalds , jejb@parisc-linux.org, deller@gmx.de, John David Anglin , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, chegu_vinod@hp.com, Waiman.Long@hp.com, tglx@linutronix.de, riel@redhat.com, akpm@linux-foundation.org, davidlohr@hp.com, hpa@zytor.com, andi@firstfloor.org, aswin@hp.com, scott.norton@hp.com, Jason Low Subject: Re: [PATCH v2] introduce atomic_pointer to fix a race condition in cancelable mcs spinlocks Message-ID: <20140602163032.GI16155@laptop.programming.kicks-ass.net> References: <20140602162525.GH16155@laptop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140602162525.GH16155@laptop.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 02, 2014 at 06:25:25PM +0200, Peter Zijlstra wrote: > I'm almost inclined to just exclude parisc from using opt spinning. > > That said, this patch still doesn't address the far more interesting > problem of actually finding these issues for these few weird archs. So why do these archs provide xchg() and cmpxchg() at all? Wouldn't it be much simpler if archs that cannot sanely do this, not provide these primitives at all? -- 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/