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| author | Ulrich Obergfell <uobergfe@redhat.com> | 2014-08-11 18:49:25 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-08-18 13:17:46 +0400 |
| commit | df577149594cefacd62740e86de080c6336d699e (patch) | |
| tree | 22dfb420cec7d57497ab875487e021bc5bd33794 /kernel/watchdog.c | |
| parent | f530504a063cfa028971e4b26ea8e0c32908de25 (diff) | |
| download | linux-df577149594cefacd62740e86de080c6336d699e.tar.xz | |
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.c | 5 |
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; } |