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[209.132.180.67]) by mx.google.com with ESMTP id m3si16773609pfi.8.2016.03.31.15.32.38 for ; Thu, 31 Mar 2016 15:32:38 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-watchdog-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-watchdog-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-watchdog-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757395AbcCaWch (ORCPT ); Thu, 31 Mar 2016 18:32:37 -0400 Received: from g9t1613g.houston.hp.com ([15.240.0.71]:51049 "EHLO g9t1613g.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755647AbcCaWcg convert rfc822-to-8bit (ORCPT ); Thu, 31 Mar 2016 18:32:36 -0400 Received: from g1t5424.austin.hp.com (g1t5424.austin.hp.com [15.216.225.54]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by g9t1613g.houston.hp.com (Postfix) with ESMTPS id D4A8A60955 for ; Thu, 31 Mar 2016 22:32:35 +0000 (UTC) Received: from G2W6309.americas.hpqcorp.net (g2w6309.austin.hp.com [16.197.64.51]) (using TLSv1.2 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by g1t5424.austin.hp.com (Postfix) with ESMTPS id 3BDD644; Thu, 31 Mar 2016 22:32:34 +0000 (UTC) Received: from G2W6309.americas.hpqcorp.net (16.197.64.51) by G2W6309.americas.hpqcorp.net (16.197.64.51) with Microsoft SMTP Server (TLS) id 15.0.1076.9; Thu, 31 Mar 2016 22:32:33 +0000 Received: from G4W6305.americas.hpqcorp.net (16.210.26.230) by G2W6309.americas.hpqcorp.net (16.197.64.51) with Microsoft SMTP Server (TLS) id 15.0.1076.9 via Frontend Transport; Thu, 31 Mar 2016 22:32:33 +0000 Received: from G9W0735.americas.hpqcorp.net ([169.254.11.159]) by G4W6305.americas.hpqcorp.net ([16.210.26.230]) with mapi id 14.03.0169.001; Thu, 31 Mar 2016 22:32:33 +0000 From: "Croxon, Nigel" To: "wim@iguana.be" , "linux-watchdog@vger.kernel.org" Subject: [PATCH] watchdog: hpwdt: Adjust documentation to match kernel module parameters Thread-Topic: [PATCH] watchdog: hpwdt: Adjust documentation to match kernel module parameters Thread-Index: AdGLnF2icMcvJYlbQ+6E7B1ytIncLQ== Date: Thu, 31 Mar 2016 22:32:32 +0000 Message-ID: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [16.210.48.17] MIME-Version: 1.0 Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Nigel Croxon Date: Thu, 31 Mar 2016 09:54:56 -0400 Subject: [PATCH] watchdog: hpwdt: Adjust documentation to match latest kernel module parameters. Adjust documentation to match latest kernel module parameters. Signed-off-by: Nigel Croxon Signed-off-by: Thomas Mingarelli --- Documentation/watchdog/hpwdt.txt | 55 ++++++++++++++++++++------------------ 1 files changed, 29 insertions(+), 26 deletions(-) -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/Documentation/watchdog/hpwdt.txt b/Documentation/watchdog/hpwdt.txt index 9488078..0cb6c16 100644 --- a/Documentation/watchdog/hpwdt.txt +++ b/Documentation/watchdog/hpwdt.txt @@ -1,64 +1,67 @@ -Last reviewed: 06/02/2009 +Last reviewed: 03/31/2016 - HP iLO2 NMI Watchdog Driver - NMI sourcing for iLO2 based ProLiant Servers + HPE iLO NMI Watchdog Driver + NMI sourcing for iLO based ProLiant Servers Documentation and Driver by - Thomas Mingarelli + Thomas Mingarelli - The HP iLO2 NMI Watchdog driver is a kernel module that provides basic + The HPE iLO NMI Watchdog driver is a kernel module that provides basic watchdog functionality and the added benefit of NMI sourcing. Both the watchdog functionality and the NMI sourcing capability need to be enabled by the user. Remember that the two modes are not dependent on one another. A user can have the NMI sourcing without the watchdog timer and vice-versa. + All references to iLO in this document imply it also works on iLO2 and all + subsequent generations. Watchdog functionality is enabled like any other common watchdog driver. That is, an application needs to be started that kicks off the watchdog timer. A basic application exists in the Documentation/watchdog/src directory called watchdog-test.c. Simply compile the C file and kick it off. If the system - gets into a bad state and hangs, the HP ProLiant iLO 2 timer register will + gets into a bad state and hangs, the HPE ProLiant iLO timer register will not be updated in a timely fashion and a hardware system reset (also known as an Automatic Server Recovery (ASR)) event will occur. - The hpwdt driver also has four (4) module parameters. They are the following: + The hpwdt driver also has three (3) module parameters. They are the following: - soft_margin - allows the user to set the watchdog timer value - allow_kdump - allows the user to save off a kernel dump image after an NMI + soft_margin - allows the user to set the watchdog timer value. + Default value is 30 seconds. + allow_kdump - allows the user to save off a kernel dump image after an NMI. + Default value is 1/ON nowayout - basic watchdog parameter that does not allow the timer to be restarted or an impending ASR to be escaped. - priority - determines whether or not the hpwdt driver is first on the - die_notify list to handle NMIs or last. The default value - for this module parameter is 0 or LAST. If the user wants to - enable NMI sourcing then reload the hpwdt driver with - priority=1 (and boot with nmi_watchdog=0). + Default valus is set when compiling the kernel. If it is set + to "Y", then there is not way of disabling the watchdog once + it has been started. NOTE: More information about watchdog drivers in general, including the ioctl interface to /dev/watchdog can be found in Documentation/watchdog/watchdog-api.txt and Documentation/IPMI.txt. - The priority parameter was introduced due to other kernel software that relied - on handling NMIs (like oprofile). Keeping hpwdt's priority at 0 (or LAST) - enables the users of NMIs for non critical events to be work as expected. - The NMI sourcing capability is disabled by default due to the inability to distinguish between "NMI Watchdog Ticks" and "HW generated NMI events" in the Linux kernel. What this means is that the hpwdt nmi handler code is called each time the NMI signal fires off. This could amount to several thousands of NMIs in a matter of seconds. If a user sees the Linux kernel's "dazed and confused" message in the logs or if the system gets into a hung state, then - the hpwdt driver can be reloaded with the "priority" module parameter set - (priority=1). + the hpwdt driver can be reloaded. 1. If the kernel has not been booted with nmi_watchdog turned off then - edit /boot/grub/menu.lst and place the nmi_watchdog=0 at the end of the - currently booting kernel line. + edit and place the nmi_watchdog=0 at the end of the currently booting + kernel line. Depending on your Linux distribution and platform setup: + For non-UEFI systems + /boot/grub/grub.conf or + /boot/grub/menu.lst + For UEFI systems + /boot/efi/EFI/distroname/grub.conf or + /boot/efi/efi/distroname/elilo.conf 2. reboot the sever 3. Once the system comes up perform a rmmod hpwdt - 4. insmod /lib/modules/`uname -r`/kernel/drivers/char/watchdog/hpwdt.ko priority=1 + 4. insmod /lib/modules/`uname -r`/kernel/drivers/watchdog/hpwdt.ko Now, the hpwdt can successfully receive and source the NMI and provide a log - message that details the reason for the NMI (as determined by the HP BIOS). + message that details the reason for the NMI (as determined by the HPE BIOS). - Below is a list of NMIs the HP BIOS understands along with the associated + Below is a list of NMIs the HPE BIOS understands along with the associated code (reason): No source found 00h @@ -92,4 +95,4 @@ Last reviewed: 06/02/2009 -- Tom Mingarelli - (thomas.mingarelli@hp.com) + (thomas.mingarelli@hpe.com)