Re: [PATCH v2 4/7] platform/x86/intel/ifs: Implement Array BIST test

From: Joseph, Jithu
Date: Wed Feb 22 2023 - 18:33:05 EST




On 2/22/2023 2:28 PM, Dave Hansen wrote:
> On 2/22/23 14:07, Joseph, Jithu wrote:
>> Since the trace has to be explicitly enabled (I thought it is okay to
>> add a more convenient custom one only to be enabled for detailed
>> analysis when required).
>
> man perf-script
>
> You should be able to write one to do exactly what you need in about 10
> minutes. No new tracepoints, no new kernel code to maintain. Knock

Thanks for the pointers. I gather that user level tools might be able to format the
msr trace output in a more convenient way (perhaps as generated by the custom driver trace)

There is still the other convenience of not having to look-up the
MSRs addresses corresponding to all the individual tests and setting the filter on them to
analyze IFS test activity (rather than enabling it via echo 1 > /sys/kernel/debug/tracing/events/intel_ifs/enable)

Agreed that for array test it is a single MSR. For other test, it is 2 separate MSRs ... there could be additional
tests in the future.


Jithu