Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759035Ab2FUXXO (ORCPT ); Thu, 21 Jun 2012 19:23:14 -0400 Received: from terminus.zytor.com ([198.137.202.10]:53917 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756920Ab2FUXXN (ORCPT ); Thu, 21 Jun 2012 19:23:13 -0400 Message-ID: <4FE3ACCA.5000705@zytor.com> Date: Thu, 21 Jun 2012 16:22:50 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Andrew Morton CC: mingo@kernel.org, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, torvalds@linux-foundation.org, zheng.z.yan@intel.com, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:perf/core] perf/x86: Add generic Intel uncore PMU support References: <1339741902-8449-6-git-send-email-zheng.z.yan@intel.com> <20120621154334.05a74517.akpm@linux-foundation.org> <4FE3A495.1030008@zytor.com> <20120621155159.239aa972.akpm@linux-foundation.org> <4FE3A9DF.20303@zytor.com> <20120621161558.824d7c6b.akpm@linux-foundation.org> <20120621161842.9319cb99.akpm@linux-foundation.org> In-Reply-To: <20120621161842.9319cb99.akpm@linux-foundation.org> X-Enigmail-Version: 1.4.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 691 Lines: 20 On 06/21/2012 04:18 PM, Andrew Morton wrote: >> >> So why is ktime_t unsigned? > > err, actually, it isn't. But lots of the APIs to manipulate ktime_t > use u64. Reason? > > I do agree that time quantities should be signed. No idea... probably because when representing an actual wall time since the POSIX epoch that can happen during the poweron time on the system, the number will be positive since the POSIX epoch predates Linux. -hpa -- 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/