Re: [PATCH v10 02/11] arm64: Make perf_callchain_kernel() use arch_stack_walk()

From: Madhavan T. Venkataraman
Date: Sat Oct 23 2021 - 08:49:56 EST




On 10/22/21 1:11 PM, Mark Rutland wrote:
> On Thu, Oct 14, 2021 at 09:58:38PM -0500, madvenka@xxxxxxxxxxxxxxxxxxx wrote:
>> From: "Madhavan T. Venkataraman" <madvenka@xxxxxxxxxxxxxxxxxxx>
>>
>> Currently, perf_callchain_kernel() in ARM64 code walks the stack using
>> start_backtrace() and walk_stackframe(). Make it use arch_stack_walk()
>> instead. This makes maintenance easier.
>>
>> Signed-off-by: Madhavan T. Venkataraman <madvenka@xxxxxxxxxxxxxxxxxxx>
>
> This looks good to me; bailing out when perf_callchain_store() can't
> accept any more entries absolutely makes sense.
>
> I gave this a spin with:
>
> | # perf record -g -c1 ls
> | # perf report
>
> ... and the recorded callchains look sane.
>
> Reviewed-by: Mark Rutland <mark.rutland@xxxxxxx>
> Tested-by: Mark Rutland <mark.rutland@xxxxxxx>
>

Thanks a lot!

> As mentioned on patch 1, I'd like to get this rebased atop Peter's
> untangling of ARCH_STACKWALK from STACKTRACE.
>

Will do.

Thanks.

Madhavan