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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 302A3C433EF for ; Fri, 6 May 2022 00:16:31 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4KvWMK6Xxdz3chY for ; Fri, 6 May 2022 10:16:29 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=IaHhIg9X; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=linux.intel.com (client-ip=192.55.52.115; helo=mga14.intel.com; envelope-from=ricardo.neri-calderon@linux.intel.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=IaHhIg9X; dkim-atps=neutral Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4KvVzZ3yBHz3cDm for ; Fri, 6 May 2022 09:59:22 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1651795162; x=1683331162; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=OMAzr1b+gR0ghYqlTvIkOvlFxefky6ROYu4/AGgKvYI=; b=IaHhIg9X7GE/Oomz0cSUED3mAGy/5t9hE3RmNeJDZK3Mx3YWH5yYYwR0 WOi0oJkZq3zCYQFfm9WpDK59u8ThjUyliYEQWvtEffZYiqyg8Lzs72pVp +JnTbxc8v1l4N7OToQtb8S3HsKlFuYqVqH2tJhnn5lCa+/i+sdGms2mGp SdSF8gB2BZCxr9rGxEYPyLX+Ie8CJBPFEYYECF61fdfP2pDJxYG723XWP 9d0bnlkMMKN8un0epCxXOAJQOrXxGQ07xyoWhGYAXQHkMjsNE1kgAifqN NGtsaF6OND1RWknEYnTvfhfV6+3ROPahpM919FQioHnOM3ZjXT0AxpnWk A==; X-IronPort-AV: E=McAfee;i="6400,9594,10338"; a="268437344" X-IronPort-AV: E=Sophos;i="5.91,203,1647327600"; d="scan'208";a="268437344" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2022 16:57:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.91,203,1647327600"; d="scan'208";a="694914455" Received: from ranerica-svr.sc.intel.com ([172.25.110.23]) by orsmga004.jf.intel.com with ESMTP; 05 May 2022 16:57:56 -0700 From: Ricardo Neri To: Thomas Gleixner , x86@kernel.org Subject: [PATCH v6 28/29] x86/tsc: Restart NMI watchdog after refining tsc_khz Date: Thu, 5 May 2022 17:00:07 -0700 Message-Id: <20220506000008.30892-29-ricardo.neri-calderon@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220506000008.30892-1-ricardo.neri-calderon@linux.intel.com> References: <20220506000008.30892-1-ricardo.neri-calderon@linux.intel.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Ravi V. Shankar" , Andi Kleen , linuxppc-dev@lists.ozlabs.org, Joerg Roedel , Ricardo Neri , Stephane Eranian , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Tony Luck , Nicholas Piggin , Suravee Suthikulpanit , Ricardo Neri , Andrew Morton , David Woodhouse , Lu Baolu Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" The HPET hardlockup detector relies on tsc_khz to estimate the value of that the TSC will have when its HPET channel fires. A refined tsc_khz helps to estimate better the expected TSC value. Using the early value of tsc_khz may lead to a large error in the expected TSC value. Restarting the NMI watchdog detector has the effect of kicking its HPET channel and make use of the refined tsc_khz. When the HPET hardlockup is not in use, restarting the NMI watchdog is a noop. Cc: Andi Kleen Cc: Stephane Eranian Cc: "Ravi V. Shankar" Cc: iommu@lists.linux-foundation.org Cc: linuxppc-dev@lists.ozlabs.org Cc: x86@kernel.org Signed-off-by: Ricardo Neri --- Changes since v5: * Introduced this patch Changes since v4 * N/A Changes since v3 * N/A Changes since v2: * N/A Changes since v1: * N/A --- arch/x86/kernel/tsc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index cafacb2e58cc..cc1843044d88 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1386,6 +1386,12 @@ static void tsc_refine_calibration_work(struct work_struct *work) /* Inform the TSC deadline clockevent devices about the recalibration */ lapic_update_tsc_freq(); + /* + * If in use, the HPET hardlockup detector relies on tsc_khz. + * Reconfigure it to make use of the refined tsc_khz. + */ + lockup_detector_reconfigure(); + /* Update the sched_clock() rate to match the clocksource one */ for_each_possible_cpu(cpu) set_cyc2ns_scale(tsc_khz, cpu, tsc_stop); -- 2.17.1