Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760588Ab2FUWsI (ORCPT ); Thu, 21 Jun 2012 18:48:08 -0400 Received: from terminus.zytor.com ([198.137.202.10]:53689 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760462Ab2FUWsG (ORCPT ); Thu, 21 Jun 2012 18:48:06 -0400 Message-ID: <4FE3A495.1030008@zytor.com> Date: Thu, 21 Jun 2012 15:47:49 -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> In-Reply-To: <20120621154334.05a74517.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: 1102 Lines: 30 On 06/21/2012 03:43 PM, Andrew Morton wrote: > > Regardless of that, we have some head-scratching to do: > > > #define UNCORE_PMU_HRTIMER_INTERVAL (60 * NSEC_PER_SEC) > > and > > #define NSEC_PER_SEC 1000000000L > > and 60 billion doesn't fit in 32 bits. So do we fix the > perf_event_intel_uncore.c callsites? Or do we fix the > UNCORE_PMU_HRTIMER_INTERVAL definition? Or do we fix the NSEC_PER_SEC > definition? > > I'm thinking perhaps the latter. What *is* the type of a nanosecond in > Linux? include/linux/ktime.h is pretty insistent that it is u64. If > so, NSEC_PER_SEC should logically have type ULL. But changing both its > size and signedness is a pretty big change. We could change the size only. The range from 9223372036.854775808 to 18446744073.709551615 seconds (292-584 years) isn't really that significant. -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/