linux-toradex.git/kernel/watchdog.c, branch v2.6.36.4

watchdog: Don't change watchdog state on read of sysctl

2011-02-17T22:47:22+00:00

commit 9ffdc6c37df131f89d52001e0ef03091b158826f upstream.

Signed-off-by: Marcin Slusarz 
[ add {}'s to fix a warning ]
Signed-off-by: Don Zickus 
Cc: Peter Zijlstra 
Cc: Frederic Weisbecker 
LKML-Reference: <1296230433-6261-3-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

watchdog: Fix sysctl consistency

2011-02-17T22:47:22+00:00

commit 397357666de6b5b6adb5fa99f9758ec8cf30ac34 upstream.

If it was not possible to enable watchdog for any cpu, switch
watchdog_enabled back to 0, because it's visible via
kernel.watchdog sysctl.

Signed-off-by: Marcin Slusarz 
Signed-off-by: Don Zickus 
Cc: Peter Zijlstra 
Cc: Frederic Weisbecker 
LKML-Reference: <1296230433-6261-2-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

watchdog: Improve initialisation error message and documentation

2011-01-07T21:58:43+00:00

commit 551423748a4eba55f2eb0fc250d757986471f187 upstream.

The error message 'NMI watchdog failed to create perf event...'
does not make it clear that this is a fatal error for the
watchdog.  It also currently prints the error value as a
pointer, rather than extracting the error code with PTR_ERR().
Fix that.

Add a note to the description of the 'nowatchdog' kernel
parameter to associate it with this message.

Reported-by: Cesare Leonardi 
Signed-off-by: Ben Hutchings 
Cc: 599368@bugs.debian.org
Cc: 608138@bugs.debian.org
Cc: Don Zickus 
Cc: Frederic Weisbecker 
LKML-Reference: <1294009362.3167.126.camel@localhost>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

lockup_detector: Sync touch_*_watchdog back to old semantics

2010-09-01T08:02:28+00:00

During my rewrite, the semantics of touch_nmi_watchdog and
touch_softlockup_watchdog changed enough to break some drivers
(mostly over preemptable regions).

These are cases where long delays on one CPU (due to
print_delay for example) can cause long delays on other
CPUs - so we must 'touch' the nmi_watchdog flag of those
other CPUs as well.

This change brings those touch_*_watchdog() functions back in line
with to how they used to work.

Signed-off-by: Don Zickus 
Acked-by: Cyrill Gorcunov 
Cc: peterz@infradead.org
Cc: fweisbec@gmail.com
LKML-Reference: <1283310009-22168-2-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar

watchdog: Don't throttle the watchdog

2010-08-23T08:48:05+00:00

Stephane reported that when the machine locks up, the regular ticks,
which are responsible to resetting the throttle count, stop too.

Hence the NMI watchdog can end up being throttled before it reports on
the locked up state, and we end up being sad..

Cure this by having the watchdog overflow reset its own throttle count.

Reported-by: Stephane Eranian 
Tested-by: Stephane Eranian 
Cc: Don Zickus 
Cc: Frederic Weisbecker 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <1282215916.1926.4696.camel@laptop>
Signed-off-by: Ingo Molnar

kernel/watchdog: Initialize 'result'

2010-07-07T06:46:42+00:00

Variable on the stack is not initialized to zero, do it
explicitly.

This bug was found by a compiler warning:

 kernel/watchdog.c:463: warning: 'result' may be used uninitialized in this function

Signed-off-by: Kulikov Vasiliy 
Acked-by: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Peter Zijlstra 
Cc: Arnaldo Carvalho de Melo 
Cc: Frederic Weisbecker 
Cc: Paul Mackerras 
Cc: Mike Galbraith 
Cc: Steven Rostedt 
LKML-Reference: <1278316854-28442-1-git-send-email-segooon@gmail.com>
Signed-off-by: Ingo Molnar

lockup_detector: Convert per_cpu to __get_cpu_var for readability

2010-05-19T09:32:14+00:00

Just a bunch of conversions as suggested by Frederic W.
__get_cpu_var() provides preemption disabled checks.

Plus it gives more readability as it makes it obvious
we are dealing locally now with these vars.

Signed-off-by: Don Zickus 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Don Zickus 
Cc: Cyrill Gorcunov 
LKML-Reference: <1274133966-18415-2-git-send-email-dzickus@redhat.com>
Signed-off-by: Frederic Weisbecker

lockup_detector: Cross arch compile fixes

2010-05-16T02:25:14+00:00

Combining the softlockup and hardlockup code causes watchdog.c
to build even without the hardlockup detection support.

So if an arch, that has the previous and the new nmi watchdog
implementations cohabiting, wants to know if the generic one
is in use, CONFIG_LOCKUP_DETECTOR is not a reliable check.
We need to use CONFIG_HARDLOCKUP_DETECTOR instead.

Fixes:
	kernel/built-in.o: In function `touch_nmi_watchdog':
	(.text+0x449bc): multiple definition of `touch_nmi_watchdog'
	arch/sparc/kernel/built-in.o:(.text+0x11b28): first defined here

Signed-off-by: Don Zickus 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Don Zickus 
Cc: Cyrill Gorcunov 
LKML-Reference: <20100514151121.GR15159@redhat.com>
[ use CONFIG_HARDLOCKUP_DETECTOR instead of CONFIG_PERF_EVENTS_NMI]
Signed-off-by: Frederic Weisbecker

lockup_detector: Introduce CONFIG_HARDLOCKUP_DETECTOR

2010-05-15T23:57:42+00:00

This new config is deemed to simplify even more the lockup detector
dependencies and can make it easier to bring a smooth sorting
between archs that support the new generic lockup detector and those
that still have their own, especially for those that are in the
middle of this migration.

Instead of checking whether we have CONFIG_LOCKUP_DETECTOR +
CONFIG_PERF_EVENTS_NMI each time an arch wants to know if it needs
to build its own lockup detector, take a shortcut with this new
config. It is enabled only if the hardlockup detection part of
the whole lockup detector is on.

Signed-off-by: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Don Zickus 
Cc: Cyrill Gorcunov

watchdog: Export touch_softlockup_watchdog

2010-05-13T06:53:33+00:00

There are modules that rely on it:

  ERROR: "touch_softlockup_watchdog" [drivers/video/nvidia/nvidiafb.ko] undefined!

Cc: Frederic Weisbecker 
Cc: Don Zickus 
Cc: Peter Zijlstra 
Cc: Cyrill Gorcunov 
LKML-Reference: <1273713674-8434-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar