LinuxLists.cc - [PATCH][v2] watchdog/hardlockup: reassign last

2019-10-15 07:08:26

Subject: [PATCH][v2] watchdog/hardlockup: reassign last_timestamp when enable nmi event

last_timestamp is not initialized and is zero after boot, or stop
to forward when nmi watchdog is disabled; and false positives still
is possible when restart NMI timer after stopping 120 seconds

so reassign last_timestamp always when enable nmi event

Fixes: 7edaeb6841df ("kernel/watchdog: Prevent false positives with turbo modes")
Signed-off-by: Li RongQing <[email protected]>
Signed-off-by: Zhang Yu <[email protected]>
---

v1-->v2: make it be able to be compiled on no CONFIG_HARDLOCKUP_CHECK_TIMESTAMP platform

kernel/watchdog_hld.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c
index 247bf0b1582c..f14d18280387 100644
--- a/kernel/watchdog_hld.c
+++ b/kernel/watchdog_hld.c
@@ -91,11 +91,24 @@ static bool watchdog_check_timestamp(void)
__this_cpu_write(last_timestamp, now);
return true;
}
+
+static void watchdog_touch_timestamp(int cpu)
+{
+
+ ktime_t now = ktime_get_mono_fast_ns();
+
+ per_cpu(last_timestamp, cpu) = now;
+}
#else
static inline bool watchdog_check_timestamp(void)
{
return true;
}
+
+static void watchdog_touch_timestamp(int cpu)
+{
+
+}
#endif

static struct perf_event_attr wd_hw_attr = {
@@ -196,6 +209,7 @@ void hardlockup_detector_perf_enable(void)
if (!atomic_fetch_inc(&watchdog_cpus))
pr_info("Enabled. Permanently consumes one hw-PMU counter.\n");

+ watchdog_touch_timestamp(smp_processor_id());
perf_event_enable(this_cpu_read(watchdog_ev));
}

@@ -274,8 +288,10 @@ void __init hardlockup_detector_perf_restart(void)
for_each_online_cpu(cpu) {
struct perf_event *event = per_cpu(watchdog_ev, cpu);

- if (event)
+ if (event) {
+ watchdog_touch_timestamp(cpu);
perf_event_enable(event);
+ }
}
}

--
2.16.2

2019-10-22 13:23:42

by Li RongQing

[permalink] [raw]

Subject: 答复: [PATCH][v2] watchdog/hardlockup: reassi gn last_timestamp when enable nmi event

Ping

Thanks

-Li

> -----?ʼ?ԭ??-----
> ??????: [email protected]
> [mailto:[email protected]] ???? Li RongQing
> ????ʱ??: 2019??10??15?? 14:34
> ?ռ???: [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]
> ????: [PATCH][v2] watchdog/hardlockup: reassign last_timestamp when
> enable nmi event
>
> last_timestamp is not initialized and is zero after boot, or stop to forward when
> nmi watchdog is disabled; and false positives still is possible when restart NMI
> timer after stopping 120 seconds
>
> so reassign last_timestamp always when enable nmi event
>
> Fixes: 7edaeb6841df ("kernel/watchdog: Prevent false positives with turbo
> modes")
> Signed-off-by: Li RongQing <[email protected]>
> Signed-off-by: Zhang Yu <[email protected]>
> ---
>
> v1-->v2: make it be able to be compiled on no
> v1-->CONFIG_HARDLOCKUP_CHECK_TIMESTAMP platform
>
> kernel/watchdog_hld.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index
> 247bf0b1582c..f14d18280387 100644
> --- a/kernel/watchdog_hld.c
> +++ b/kernel/watchdog_hld.c
> @@ -91,11 +91,24 @@ static bool watchdog_check_timestamp(void)
> __this_cpu_write(last_timestamp, now);
> return true;
> }
> +
> +static void watchdog_touch_timestamp(int cpu) {
> +
> + ktime_t now = ktime_get_mono_fast_ns();
> +
> + per_cpu(last_timestamp, cpu) = now;
> +}
> #else
> static inline bool watchdog_check_timestamp(void) {
> return true;
> }
> +
> +static void watchdog_touch_timestamp(int cpu) {
> +
> +}
> #endif
>
> static struct perf_event_attr wd_hw_attr = { @@ -196,6 +209,7 @@ void
> hardlockup_detector_perf_enable(void)
> if (!atomic_fetch_inc(&watchdog_cpus))
> pr_info("Enabled. Permanently consumes one hw-PMU counter.\n");
>
> + watchdog_touch_timestamp(smp_processor_id());
> perf_event_enable(this_cpu_read(watchdog_ev));
> }
>
> @@ -274,8 +288,10 @@ void __init hardlockup_detector_perf_restart(void)
> for_each_online_cpu(cpu) {
> struct perf_event *event = per_cpu(watchdog_ev, cpu);
>
> - if (event)
> + if (event) {
> + watchdog_touch_timestamp(cpu);
> perf_event_enable(event);
> + }
> }
> }
>
> --
> 2.16.2

2019-11-07 11:13:26

by Li RongQing

[permalink] [raw]

Subject: 答复: [PATCH][v2] watchdog/hardlockup: reassi gn last_timestamp when enable nmi event

2019-11-22 11:16:11

by Li RongQing

[permalink] [raw]

Subject: 答复: [PATCH][v2] watchdog/hardlockup: reassi gn last_timestamp when enable nmi event

Ping

Thanks
-RongQing

> -----?ʼ?ԭ??-----
> ??????: Li,Rongqing
> ????ʱ??: 2019??11??7?? 18:54
> ?ռ???: Li,Rongqing <[email protected]>; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]
> ????: ????: [PATCH][v2] watchdog/hardlockup: reassign last_timestamp when
> enable nmi event
>
> Ping
>
> Thanks
>
> -Li
>
> > -----?ʼ?ԭ??-----
> > ??????: [email protected]
> > [mailto:[email protected]] ???? Li RongQing
> > ????ʱ??: 2019??10??15?? 14:34
> > ?ռ???: [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected]
> > ????: [PATCH][v2] watchdog/hardlockup: reassign last_timestamp when
> > enable nmi event
> >
> > last_timestamp is not initialized and is zero after boot, or stop to
> > forward when nmi watchdog is disabled; and false positives still is
> > possible when restart NMI timer after stopping 120 seconds
> >
> > so reassign last_timestamp always when enable nmi event
> >
> > Fixes: 7edaeb6841df ("kernel/watchdog: Prevent false positives with
> > turbo
> > modes")
> > Signed-off-by: Li RongQing <[email protected]>
> > Signed-off-by: Zhang Yu <[email protected]>
> > ---
> >
> > v1-->v2: make it be able to be compiled on no
> > v1-->CONFIG_HARDLOCKUP_CHECK_TIMESTAMP platform
> >
> > kernel/watchdog_hld.c | 18 +++++++++++++++++-
> > 1 file changed, 17 insertions(+), 1 deletion(-)
> >
> > diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index
> > 247bf0b1582c..f14d18280387 100644
> > --- a/kernel/watchdog_hld.c
> > +++ b/kernel/watchdog_hld.c
> > @@ -91,11 +91,24 @@ static bool watchdog_check_timestamp(void)
> > __this_cpu_write(last_timestamp, now);
> > return true;
> > }
> > +
> > +static void watchdog_touch_timestamp(int cpu) {
> > +
> > + ktime_t now = ktime_get_mono_fast_ns();
> > +
> > + per_cpu(last_timestamp, cpu) = now;
> > +}
> > #else
> > static inline bool watchdog_check_timestamp(void) {
> > return true;
> > }
> > +
> > +static void watchdog_touch_timestamp(int cpu) {
> > +
> > +}
> > #endif
> >
> > static struct perf_event_attr wd_hw_attr = { @@ -196,6 +209,7 @@ void
> > hardlockup_detector_perf_enable(void)
> > if (!atomic_fetch_inc(&watchdog_cpus))
> > pr_info("Enabled. Permanently consumes one hw-PMU counter.\n");
> >
> > + watchdog_touch_timestamp(smp_processor_id());
> > perf_event_enable(this_cpu_read(watchdog_ev));
> > }
> >
> > @@ -274,8 +288,10 @@ void __init hardlockup_detector_perf_restart(void)
> > for_each_online_cpu(cpu) {
> > struct perf_event *event = per_cpu(watchdog_ev, cpu);
> >
> > - if (event)
> > + if (event) {
> > + watchdog_touch_timestamp(cpu);
> > perf_event_enable(event);
> > + }
> > }
> > }
> >
> > --
> > 2.16.2

2019-12-05 10:20:43

by Li RongQing

[permalink] [raw]

Subject: 答复: [PATCH][v2] watchdog/hardlockup: reassi gn last_timestamp when enable nmi event

Ping

thanks

-Li

>> [PATCH][v2] watchdog/hardlockup: reassign last_timestamp when
> > enable nmi event
> >
> > last_timestamp is not initialized and is zero after boot, or stop to
> > forward when nmi watchdog is disabled; and false positives still is
> > possible when restart NMI timer after stopping 120 seconds
> >
> > so reassign last_timestamp always when enable nmi event
> >
> > Fixes: 7edaeb6841df ("kernel/watchdog: Prevent false positives with
> > turbo
> > modes")
> > Signed-off-by: Li RongQing <[email protected]>
> > Signed-off-by: Zhang Yu <[email protected]>
> > ---
> >
> > v1-->v2: make it be able to be compiled on no
> > v1-->CONFIG_HARDLOCKUP_CHECK_TIMESTAMP platform
> >
> > kernel/watchdog_hld.c | 18 +++++++++++++++++-
> > 1 file changed, 17 insertions(+), 1 deletion(-)
> >
> > diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index
> > 247bf0b1582c..f14d18280387 100644
> > --- a/kernel/watchdog_hld.c
> > +++ b/kernel/watchdog_hld.c
> > @@ -91,11 +91,24 @@ static bool watchdog_check_timestamp(void)
> > __this_cpu_write(last_timestamp, now);
> > return true;
> > }
> > +
> > +static void watchdog_touch_timestamp(int cpu) {
> > +
> > + ktime_t now = ktime_get_mono_fast_ns();
> > +
> > + per_cpu(last_timestamp, cpu) = now;
> > +}
> > #else
> > static inline bool watchdog_check_timestamp(void) {
> > return true;
> > }
> > +
> > +static void watchdog_touch_timestamp(int cpu) {
> > +
> > +}
> > #endif
> >
> > static struct perf_event_attr wd_hw_attr = { @@ -196,6 +209,7 @@ void
> > hardlockup_detector_perf_enable(void)
> > if (!atomic_fetch_inc(&watchdog_cpus))
> > pr_info("Enabled. Permanently consumes one hw-PMU counter.\n");
> >
> > + watchdog_touch_timestamp(smp_processor_id());
> > perf_event_enable(this_cpu_read(watchdog_ev));
> > }
> >
> > @@ -274,8 +288,10 @@ void __init hardlockup_detector_perf_restart(void)
> > for_each_online_cpu(cpu) {
> > struct perf_event *event = per_cpu(watchdog_ev, cpu);
> >
> > - if (event)
> > + if (event) {
> > + watchdog_touch_timestamp(cpu);
> > perf_event_enable(event);
> > + }
> > }
> > }
> >
> > --

> > 2.16.2