Messages in this thread | | | Date | Thu, 16 Sep 2021 10:29:04 +0200 | From | Petr Mladek <> | Subject | Re: [PATCH 3/5] kernel/watchdog: adapt the watchdog_hld interface for async model |
| |
On Wed 2021-09-15 11:51:01, Pingfan Liu wrote: > When lockup_detector_init()->watchdog_nmi_probe(), PMU may be not ready > yet. E.g. on arm64, PMU is not ready until > device_initcall(armv8_pmu_driver_init). And it is deeply integrated > with the driver model and cpuhp. Hence it is hard to push this > initialization before smp_init(). > > But it is easy to take an opposite approach by enabling watchdog_hld to > get the capability of PMU async.
This is another cryptic description. I have probably got it after looking at the 5th patch (was not Cc :-(
> The async model is achieved by introducing an extra parameter notifier > of watchdog_nmi_probe().
I would say that the code is horrible and looks too complex.
What about simply calling watchdog_nmi_probe() and lockup_detector_setup() once again when watchdog_nmi_probe() failed in lockup_detector_init()?
Or do not call lockup_detector_init() at all in kernel_init_freeable() when PMU is not ready yet.
Best Regards, Petr
| |