linux-toradex.git/kernel/watchdog.c, branch v2.6.37.2

watchdog: Fix broken nowatchdog logic

2011-02-17T23:15:04+00:00

commit 4135038a582c20ffdadfcf6564852e0b72a20968 upstream.

Passing nowatchdog to kernel disables 2 things: creation of
watchdog threads AND initialization of percpu watchdog_hrtimer.
As hrtimers are initialized only at boot it's not possible to
enable watchdog later - for me all watchdog threads started to
eat 100% of CPU time, but they could just crash.

Additionally, even if these threads would start properly,
watchdog_disable_all_cpus was guarded by no_watchdog check, so
you couldn't disable watchdog.

To fix this, remove no_watchdog variable and use already
existing watchdog_enabled variable.

Signed-off-by: Marcin Slusarz 
[ removed another no_watchdog instance ]
Signed-off-by: Don Zickus 
Cc: Stephane Eranian 
Cc: Peter Zijlstra 
Cc: Frederic Weisbecker 
LKML-Reference: <1296230433-6261-1-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar

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

2011-02-17T23:14:45+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

2011-02-17T23:14:45+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

2011-01-03T04:25:52+00:00

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 
Cc:  # .37.x and later
LKML-Reference: <1294009362.3167.126.camel@localhost>
Signed-off-by: Ingo Molnar

watchdog: Fix section mismatch and potential undefined behavior.

2010-11-06T00:45:35+00:00

Commit d9ca07a05ce1 ("watchdog: Avoid kernel crash when disabling
watchdog") introduces a section mismatch.

Now that we reference no_watchdog from non-__init code it can no longer
be __initdata.

Signed-off-by: David Daney 
Cc: Stephane Eranian 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Signed-off-by: Linus Torvalds

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2010-10-21T19:54:49+00:00

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (163 commits)
  tracing: Fix compile issue for trace_sched_wakeup.c
  [S390] hardirq: remove pointless header file includes
  [IA64] Move local_softirq_pending() definition
  perf, powerpc: Fix power_pmu_event_init to not use event->ctx
  ftrace: Remove recursion between recordmcount and scripts/mod/empty
  jump_label: Add COND_STMT(), reducer wrappery
  perf: Optimize sw events
  perf: Use jump_labels to optimize the scheduler hooks
  jump_label: Add atomic_t interface
  jump_label: Use more consistent naming
  perf, hw_breakpoint: Fix crash in hw_breakpoint creation
  perf: Find task before event alloc
  perf: Fix task refcount bugs
  perf: Fix group moving
  irq_work: Add generic hardirq context callbacks
  perf_events: Fix transaction recovery in group_sched_in()
  perf_events: Fix bogus AMD64 generic TLB events
  perf_events: Fix bogus context time tracking
  tracing: Remove parent recording in latency tracer graph options
  tracing: Use one prologue for the preempt irqs off tracer function tracers
  ...

Merge branch 'linus' into core/locking

2010-10-12T15:27:28+00:00

Reason: Pull in the semaphore related changes

Signed-off-by: Thomas Gleixner

perf events: Clean up pid passing

2010-09-15T08:44:00+00:00

The kernel perf event creation path shouldn't use find_task_by_vpid()
because a vpid exists in a specific namespace. find_task_by_vpid() uses
current's pid namespace which isn't always the correct namespace to use
for the vpid in all the places perf_event_create_kernel_counter() (and
thus find_get_context()) is called.

The goal is to clean up pid namespace handling and prevent bugs like:

	https://bugzilla.kernel.org/show_bug.cgi?id=17281

Instead of using pids switch find_get_context() to use task struct
pointers directly. The syscall is responsible for resolving the pid to
a task struct. This moves the pid namespace resolution into the syscall
much like every other syscall that takes pid parameters.

Signed-off-by: Matt Helsley 
Signed-off-by: Peter Zijlstra 
Cc: Robin Green 
Cc: Prasad 
Cc: Arnaldo Carvalho de Melo 
Cc: Steven Rostedt 
Cc: Will Deacon 
Cc: Mahesh Salgaonkar 
LKML-Reference: 
Signed-off-by: Ingo Molnar

watchdog: Avoid kernel crash when disabling watchdog

2010-09-15T08:43:58+00:00

In case you boot with the watchdog disabled, i.e., nowatchdog, then,
if you try to disable it via /proc/sys/kernel/watchdog, you get
a kernel crash. The reason is that you are trying to cancel a hrtimer
which has never been initialized.

This patch fixes this by skipping execution of
watchdog_disable_all_cpus() when the watchdog is marked
disabled from boot.

Signed-off-by: Stephane Eranian 
Signed-off-by: Peter Zijlstra 
LKML-Reference: <4c8f7a23.cae9d80a.2c11.0bb4@mx.google.com>
Signed-off-by: Ingo Molnar

Merge branch 'perf/urgent' into perf/core

2010-09-09T18:40:08+00:00

Merge reason: Pick up pending fixes before applying dependent new changes.

Signed-off-by: Ingo Molnar