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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C584C4332F for ; Thu, 13 Oct 2022 16:05:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229948AbiJMQFt (ORCPT ); Thu, 13 Oct 2022 12:05:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229552AbiJMQFr (ORCPT ); Thu, 13 Oct 2022 12:05:47 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D247AE085 for ; Thu, 13 Oct 2022 09:05:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1665677146; x=1697213146; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=2JjVQsMb4D2fizdgIfbXopLKa+DgIUyh/kLuROOfp7I=; b=nf61IkTFcMnxRBRKEw9V/ACBty9sU8g7gRBQQMBsyq8xY/VjGQjnG75o DQq9w+vDQOyOrNC3Dv0q0DY0xfXR2cEWeFYwtG6mfCqcSAO6TXl/r0wHV /f/QZXgnpslC+H+kQ0l0Ehmcg6fU/eRAl2u25XjAtVY+Bep+aQf9PRs9F Onk5jYNc9XDmGV+LHS2Kdwtrnp6JZdxT8iF3Qf1oSF0jLszGtd4FwckB0 hkIa0D0cCQd/6lifedCDY+50H1oNoXZWUqY5m73a8z4yORL7zYESPlttU ZNUjdfU0DaeOpCYb9pTFlA4A9b/zsTak449zRjTxQ+lvCrp8I/w/LknyM A==; X-IronPort-AV: E=McAfee;i="6500,9779,10499"; a="302735515" X-IronPort-AV: E=Sophos;i="5.95,182,1661842800"; d="scan'208";a="302735515" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2022 09:02:55 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10499"; a="716396818" X-IronPort-AV: E=Sophos;i="5.95,182,1661842800"; d="scan'208";a="716396818" Received: from mkucejko-mobl.ger.corp.intel.com (HELO [10.213.24.166]) ([10.213.24.166]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2022 09:02:48 -0700 Message-ID: Date: Thu, 13 Oct 2022 09:02:43 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v2] x86/tsc: Extend watchdog check exemption to 4-Sockets platform Content-Language: en-US To: Feng Tang , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Peter Zijlstra , x86@kernel.org, linux-kernel@vger.kernel.org Cc: rui.zhang@intel.com, tim.c.chen@intel.com, Xiongfeng Wang , Yu Liao References: <20221013131200.973649-1-feng.tang@intel.com> From: Dave Hansen In-Reply-To: <20221013131200.973649-1-feng.tang@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/13/22 06:12, Feng Tang wrote: > @@ -1217,7 +1217,7 @@ static void __init check_system_tsc_reliable(void) > if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && > boot_cpu_has(X86_FEATURE_NONSTOP_TSC) && > boot_cpu_has(X86_FEATURE_TSC_ADJUST) && > - nr_online_nodes <= 2) > + nr_online_nodes <= 4) > tsc_disable_clocksource_watchdog(); I still don't think we should perpetuate this hack. This just plain doesn't work in numa=off numa=fake=... or presumably in cases where NUMA is disabled in the firmware and memory is interleaved across all sockets. It also presumably doesn't work on two-socket systems that have Cluster-on-Die or Sub-NUMA-Clustering where a single socket is chopped up into multiple nodes.