Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261429AbVE3LJR (ORCPT ); Mon, 30 May 2005 07:09:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261441AbVE3LJB (ORCPT ); Mon, 30 May 2005 07:09:01 -0400 Received: from one.firstfloor.org ([213.235.205.2]:49042 "EHLO one.firstfloor.org") by vger.kernel.org with ESMTP id S261433AbVE3LG6 (ORCPT ); Mon, 30 May 2005 07:06:58 -0400 To: Kyle Moffett Cc: john cooper , linux-kernel@vger.kernel.org Subject: Re: spinaphore conceptual draft References: <934f64a205052715315c21d722@mail.gmail.com> From: Andi Kleen Date: Mon, 30 May 2005 13:06:57 +0200 In-Reply-To: (Kyle Moffett's message of "Fri, 27 May 2005 21:04:37 -0400") Message-ID: User-Agent: Gnus/5.110002 (No Gnus v0.2) Emacs/21.3 (gnu/linux) 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: 733 Lines: 18 Kyle Moffett writes: > if (unlikely(CONFIG_SPINAPHORE_CONTEXT_SWITCH < > ( queued*atomic_get(&sph->hold_time) - > fast_monotonic_count() - start_time On many architectures (including popular ones like AMD x86-64) there is no reliable fast monotonic (1) count unfortunately - except perhaps jiffies, but that would be far to coarse grained for your purpose. -Andi (1) reliable fast monotonic - chose any two instead. - 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/