lkml.org 
[lkml]   [2019]   [Mar]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:core/urgent] watchdog: Respect watchdog cpumask on CPU hotplug
Commit-ID:  7dd47617114921fdd8c095509e5e7b4373cc44a1
Gitweb: https://git.kernel.org/tip/7dd47617114921fdd8c095509e5e7b4373cc44a1
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 26 Mar 2019 22:51:02 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 28 Mar 2019 13:32:01 +0100

watchdog: Respect watchdog cpumask on CPU hotplug

The rework of the watchdog core to use cpu_stop_work broke the watchdog
cpumask on CPU hotplug.

The watchdog_enable/disable() functions are now called unconditionally from
the hotplug callback, i.e. even on CPUs which are not in the watchdog
cpumask. As a consequence the watchdog can become unstoppable.

Only invoke them when the plugged CPU is in the watchdog cpumask.

Fixes: 9cf57731b63e ("watchdog/softlockup: Replace "watchdog/%u" threads with cpu_stop_work")
Reported-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1903262245490.1789@nanos.tec.linutronix.de

---
kernel/watchdog.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 403c9bd90413..6a5787233113 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -554,13 +554,15 @@ static void softlockup_start_all(void)

int lockup_detector_online_cpu(unsigned int cpu)
{
- watchdog_enable(cpu);
+ if (cpumask_test_cpu(cpu, &watchdog_allowed_mask))
+ watchdog_enable(cpu);
return 0;
}

int lockup_detector_offline_cpu(unsigned int cpu)
{
- watchdog_disable(cpu);
+ if (cpumask_test_cpu(cpu, &watchdog_allowed_mask))
+ watchdog_disable(cpu);
return 0;
}

\
 
 \ /
  Last update: 2019-03-28 13:39    [W:0.065 / U:34.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site