From: Aristeu Rozanski <aris@redhat.com>
To: Randy Dunlap <randy.dunlap@oracle.com>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>
Subject: [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation v2
Date: Thu, 30 Oct 2008 13:08:50 -0400 [thread overview]
Message-ID: <20081030170850.GQ771@redhat.com> (raw)
In-Reply-To: <20081030091921.79c04ec6.randy.dunlap@oracle.com>
This patch updates the /proc/sys/kernel/nmi_watchdog documentation.
Updated: included Randy Dunlap's corrections.
Signed-off-by: Aristeu Rozanski <aris@redhat.com>
---
Documentation/filesystems/proc.txt | 11 +++++++----
Documentation/nmi_watchdog.txt | 5 +++++
2 files changed, 12 insertions(+), 4 deletions(-)
--- linus-2.6.orig/Documentation/nmi_watchdog.txt 2008-10-24 11:41:30.000000000 -0400
+++ linus-2.6/Documentation/nmi_watchdog.txt 2008-10-30 13:05:46.000000000 -0400
@@ -69,6 +69,11 @@ to the overall system performance.
On x86 nmi_watchdog is disabled by default so you have to enable it with
a boot time parameter.
+It's possible to disable the NMI watchdog in run-time by writing "0" to
+/proc/sys/kernel/nmi_watchdog. Writing "1" to the same file will re-enable
+the NMI watchdog. Notice that you still need to use "nmi_watchdog=" parameter
+at boot time.
+
NOTE: In kernels prior to 2.4.2-ac18 the NMI-oopser is enabled unconditionally
on x86 SMP boxes.
--- linus-2.6.orig/Documentation/filesystems/proc.txt 2008-10-24 11:41:28.000000000 -0400
+++ linus-2.6/Documentation/filesystems/proc.txt 2008-10-30 13:05:31.000000000 -0400
@@ -1338,10 +1338,13 @@ nmi_watchdog
Enables/Disables the NMI watchdog on x86 systems. When the value is non-zero
the NMI watchdog is enabled and will continuously test all online cpus to
-determine whether or not they are still functioning properly.
-
-Because the NMI watchdog shares registers with oprofile, by disabling the NMI
-watchdog, oprofile may have more registers to utilize.
+determine whether or not they are still functioning properly. Currently,
+passing "nmi_watchdog=" parameter at boot time is required for this function
+to work.
+
+If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel parameter), the
+NMI watchdog shares registers with oprofile. By disabling the NMI watchdog,
+oprofile may have more registers to utilize.
msgmni
------
next prev parent reply other threads:[~2008-10-30 17:08 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-30 15:17 [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation Aristeu Rozanski
2008-10-30 15:45 ` Cyrill Gorcunov
2008-10-30 15:51 ` Aristeu Rozanski
2008-10-30 15:51 ` Cyrill Gorcunov
2008-10-30 16:19 ` Randy Dunlap
2008-10-30 17:08 ` Aristeu Rozanski [this message]
2008-10-30 17:13 ` [PATCH] nmi_watchdog: update procfs nmi_watchdog file documentation v2 Randy Dunlap
2008-10-30 18:07 ` Ingo Molnar
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