Re: [PATCH 3/5] kernel/watchdog_hld: Ensure CPU-bound context when creating hardlockup detector event
From: Petr Mladek
Date: Fri Feb 25 2022 - 08:15:54 EST
On Sat 2022-02-12 18:43:47, Lecopzer Chen wrote:
> From: Pingfan Liu <kernelfans@xxxxxxxxx>
>
> from: Pingfan Liu <kernelfans@xxxxxxxxx>
>
> hardlockup_detector_event_create() should create perf_event on the
> current CPU. Preemption could not get disabled because
> perf_event_create_kernel_counter() allocates memory. Instead,
> the CPU locality is achieved by processing the code in a per-CPU
> bound kthread.
>
> Add a check to prevent mistakes when calling the code in another
> code path.
>
> Signed-off-by: Pingfan Liu <kernelfans@xxxxxxxxx>
> Co-developed-by: Lecopzer Chen <lecopzer.chen@xxxxxxxxxxxx>
> Signed-off-by: Lecopzer Chen <lecopzer.chen@xxxxxxxxxxxx>
Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
Best Regards,
Petr