The patch titled Subject: kernel/watchdog.c: fix print-once on enable has been added to the -mm tree. Its filename is watchdog-fix-print-once-on-enable.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/watchdog-fix-print-once-on-enable.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/watchdog-fix-print-once-on-enable.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Ulrich Obergfell <uobergfe@xxxxxxxxxx> Subject: kernel/watchdog.c: 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@xxxxxxxxxx> Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx> Signed-off-by: Don Zickus <dzickus@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/watchdog.c | 3 +++ 1 file changed, 3 insertions(+) diff -puN kernel/watchdog.c~watchdog-fix-print-once-on-enable kernel/watchdog.c --- a/kernel/watchdog.c~watchdog-fix-print-once-on-enable +++ a/kernel/watchdog.c @@ -525,6 +525,9 @@ static void watchdog_nmi_disable(unsigne /* 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 _ Patches currently in -mm which might be from uobergfe@xxxxxxxxxx are watchdog-fix-print-once-on-enable.patch watchdog-control-hard-lockup-detection-default.patch kvm-ensure-hard-lockup-detection-is-disabled-by-default.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html