From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B614CC10F13 for ; Tue, 9 Apr 2019 02:03:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F433213F2 for ; Tue, 9 Apr 2019 02:03:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726730AbfDICD6 (ORCPT ); Mon, 8 Apr 2019 22:03:58 -0400 Received: from mga04.intel.com ([192.55.52.120]:35761 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726133AbfDICD5 (ORCPT ); Mon, 8 Apr 2019 22:03:57 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Apr 2019 19:03:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,327,1549958400"; d="scan'208";a="221741672" Received: from ranerica-svr.sc.intel.com ([172.25.110.23]) by orsmga001.jf.intel.com with ESMTP; 08 Apr 2019 19:03:56 -0700 Date: Mon, 8 Apr 2019 19:02:47 -0700 From: Ricardo Neri To: Thomas Gleixner Cc: Ingo Molnar , Borislav Petkov , Ashok Raj , Andi Kleen , Peter Zijlstra , "Ravi V. Shankar" , x86@kernel.org, linux-kernel@vger.kernel.org, Ricardo Neri , "H. Peter Anvin" , Tony Luck , Clemens Ladisch , Arnd Bergmann , Philippe Ombredanne , Kate Stewart , "Rafael J. Wysocki" , Mimi Zohar , Jan Kiszka , Nick Desaulniers , Masahiro Yamada , Nayna Jain Subject: Re: [RFC PATCH v2 12/14] x86/watchdog/hardlockup/hpet: Determine if HPET timer caused NMI Message-ID: <20190409020247.GA7008@ranerica-svr.sc.intel.com> References: <1551283518-18922-1-git-send-email-ricardo.neri-calderon@linux.intel.com> <1551283518-18922-13-git-send-email-ricardo.neri-calderon@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 26, 2019 at 09:55:35PM +0100, Thomas Gleixner wrote: > On Wed, 27 Feb 2019, Ricardo Neri wrote: > > @@ -62,7 +67,18 @@ static inline void set_comparator(struct hpet_hld_data *hdata, > > static void kick_timer(struct hpet_hld_data *hdata, bool force) > > { > > bool kick_needed = force || !(hdata->flags & HPET_DEV_PERI_CAP); > > - unsigned long new_compare, count; > > + unsigned long tsc_curr, tsc_delta, new_compare, count; > > + > > + /* Start obtaining the current TSC and HPET counts. */ > > + tsc_curr = rdtsc(); > > + > > + if (kick_needed) > > + count = get_count(); > > Can you please keep the TSC code in one block and the HPET block in the > next one? Having this inbetween is really bad to follow. > > It really does not matter whether you read the HPET counter before or after > the calculation. This is a crystal ball estimation anyway so a few cyles > more or less are completely irrelevant. Sure! I will implement this change. Thanks and BR, Ricardo > > > + tsc_delta = (unsigned long)watchdog_thresh * (unsigned long)tsc_khz > > + * 1000L; > > + hdata->tsc_next = tsc_curr + tsc_delta; > > + hdata->tsc_next_error = tsc_delta >> 6; > > Thanks, > > tglx