From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752373AbZIWWgZ (ORCPT ); Wed, 23 Sep 2009 18:36:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752275AbZIWWgX (ORCPT ); Wed, 23 Sep 2009 18:36:23 -0400 Received: from sj-iport-6.cisco.com ([171.71.176.117]:25638 "EHLO sj-iport-6.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752262AbZIWWgW (ORCPT ); Wed, 23 Sep 2009 18:36:22 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApoEADc/ukqrR7O6/2dsb2JhbAC+aYhPAY92BYQb X-IronPort-AV: E=Sophos;i="4.44,440,1249257600"; d="scan'208";a="394786026" From: Roland Dreier To: Ingo Molnar , Thomas Gleixner Cc: linux-kernel@vger.kernel.org Subject: [PATCH 1/2] x86: Reduce verbosity of "TSC is reliable" message X-Message-Flag: Warning: May contain useful information Date: Wed, 23 Sep 2009 15:33:23 -0700 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.91 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-OriginalArrivalTime: 23 Sep 2009 22:33:23.0896 (UTC) FILETIME=[DC6A3380:01CA3C9D] Authentication-Results: sj-dkim-2; header.From=rdreier@cisco.com; dkim=pass ( sig from cisco.com/sjdkim2002 verified; ); Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On modern systems, the kernel prints the message Skipping synchronization checks as TSC is reliable. once for every non-boot CPU. This gets kind of ridiculous on huge systems; for example, on a 64-thread system I was lucky enough to get: $ dmesg | grep 'TSC is reliable' | wc 63 567 4221 There's no point to doing this for every CPU, since the code is just checking the boot CPU anyway, so change this to a printk_once() to make the message appears only once. Signed-off-by: Roland Dreier --- arch/x86/kernel/tsc_sync.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/tsc_sync.c b/arch/x86/kernel/tsc_sync.c index 027b5b4..f379309 100644 --- a/arch/x86/kernel/tsc_sync.c +++ b/arch/x86/kernel/tsc_sync.c @@ -114,7 +114,7 @@ void __cpuinit check_tsc_sync_source(int cpu) return; if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE)) { - pr_info("Skipping synchronization checks as TSC is reliable.\n"); + printk_once(KERN_INFO "Skipping synchronization checks as TSC is reliable.\n"); return; }