Messages in this thread Patch in this message | | | From | Andrew Jones <> | Subject | [PATCH 1/3] watchdog: fix print-once on enable | Date | Thu, 24 Jul 2014 12:13:29 +0200 |
| |
From: Ulrich Obergfell <uobergfe@redhat.com>
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> --- kernel/watchdog.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index c3319bd1b0408..c985a21926545 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -511,6 +511,9 @@ static void watchdog_nmi_disable(unsigned int cpu) /* should be in cleanup, but blocks oprofile */ perf_event_release_kernel(event); } + if (cpu == 0) + /* watchdog_nmi_enable() expects this to be zero initially. */ + cpu0_err = 0; return; } #else -- 1.9.3
| |