Re: [PATCH v10 03/11] arm64: Make get_wchan() use arch_stack_walk()

From: Madhavan T. Venkataraman
Date: Thu Oct 21 2021 - 08:30:45 EST


I will take a look at what Peter has done and will coordinate with him.

Thanks.

Madhavan

On 10/20/21 11:10 AM, Mark Brown wrote:
> On Thu, Oct 14, 2021 at 09:58:39PM -0500, madvenka@xxxxxxxxxxxxxxxxxxx wrote:
>> From: "Madhavan T. Venkataraman" <madvenka@xxxxxxxxxxxxxxxxxxx>
>>
>> Currently, get_wchan() in ARM64 code walks the stack using start_backtrace()
>> and unwind_frame(). Make it use arch_stack_walk() instead. This makes
>> maintenance easier.
>
> This overlaps with some very similar updates that Peter Zijlstra is
> working on which addresses some existing problems with wchan:
>
> https://lore.kernel.org/all/20211008111527.438276127@xxxxxxxxxxxxx/
>
> It probably makes sense for you to coordinate with Peter here, some of
> that series is already merged up to his patch 6 which looks very
> similar to what you've got here. In that thread you'll see that Mark
> Rutland spotted an issue with the handling of __switch_to() on arm64
> which probably also applies to your change.
>
>
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