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authorUlrich Obergfell <uobergfe@redhat.com>2014-08-11 10:49:25 -0400
committerIngo Molnar <mingo@kernel.org>2014-08-18 11:17:46 +0200
commitdf577149594cefacd62740e86de080c6336d699e (patch)
tree22dfb420cec7d57497ab875487e021bc5bd33794 /kernel/watchdog.c
parentf530504a063cfa028971e4b26ea8e0c32908de25 (diff)
watchdog: Fix print-once on enable
This patch avoids printing the message 'enabled on all CPUs, ...' multiple times. For example, the issue can occur in the following scenario: 1) watchdog_nmi_enable() fails to enable PMU counters and sets cpu0_err. 2) 'echo [0|1] > /proc/sys/kernel/nmi_watchdog' is executed to disable and re-enable the watchdog mechanism 'on the fly'. 3) If watchdog_nmi_enable() succeeds to enable PMU counters, each CPU will print the message because step1 left behind a non-zero cpu0_err. if (!IS_ERR(event)) { if (cpu == 0 || cpu0_err) pr_info("enabled on all CPUs, ...") The patch avoids this by clearing cpu0_err in watchdog_nmi_disable(). Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: pbonzini@redhat.com Link: http://lkml.kernel.org/r/1407768567-171794-4-git-send-email-dzickus@redhat.com [ Applied small cleanups. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/watchdog.c')
-rw-r--r--kernel/watchdog.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 4c2e11ce5425..df5494edf694 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -506,7 +506,10 @@ static void watchdog_nmi_disable(unsigned int cpu)
/* should be in cleanup, but blocks oprofile */
perf_event_release_kernel(event);
}
- return;
+ if (cpu == 0) {
+ /* watchdog_nmi_enable() expects this to be zero initially. */
+ cpu0_err = 0;
+ }
}
#else
static int watchdog_nmi_enable(unsigned int cpu) { return 0; }