Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752724AbaKDWeX (ORCPT ); Tue, 4 Nov 2014 17:34:23 -0500 Received: from ozlabs.org ([103.22.144.67]:52866 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752056AbaKDWeW (ORCPT ); Tue, 4 Nov 2014 17:34:22 -0500 Date: Wed, 5 Nov 2014 09:34:20 +1100 From: Anton Blanchard To: uobergfe@redhat.com, drjones@redhat.com, dzickus@redhat.com, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org Subject: Confusing behaviour with /proc/sys/kernel/nmi_watchdog Message-ID: <20141105093420.1c7500d8@kryten> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, commit 9919e39a1738 ("kvm: ensure hard lockup detection is disabled by default") provided a way for the kernel to disable the hard lockup detector at runtime. I'm using it on ppc64 but notice some weird behaviour with the nmi_watchdog procfs variable. At boot, that the hard lockup detector appears to be enabled even when we disable it via watchdog_enable_hardlockup_detector(false): # cat /proc/sys/kernel/nmi_watchdog 1 I have to echo 0 to it then echo 1 again to enable it. Anton -- 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/