Re: [PATCH] perf record/arm-spe: Override attr->sample_period for non-libpfm4 events

[German Gomez]

Hi James,

On 17/01/2022 09:59, James Clark wrote:
>
> On 14/01/2022 21:21, German Gomez wrote:
>> A previous commit preventing attr->sample_period values from being
>> overridden in pfm events changed a related behaviour in arm_spe.
>>
>> Before this patch:
>> perf record -c 10000 -e arm_spe_0// -- sleep 1
>>
>> Would not yield an SPE event with period=10000, because the arm-spe code
> Just to clarify, this seems like it should say "Would yield", not "Would not yield",
> as in it was previously working?

"this patch" refers to the patch I'm sending, not the one it's fixing.
I might have to rewrite this to make it more clear. How about:

===
A previous patch preventing "attr->sample_period" values from being
overridden in pfm events changed a related behaviour in arm-spe.

Before said patch:
perf record -c 10000 -e arm_spe_0// -- sleep 1

Would yield an SPE event with period=10000. After the patch, the period
in "-c 10000" was being ignored because the arm-spe code initializes
sample_period to a non-zero value.

This patch restores the previous behaviour for non-libpfm4 events.
===

Thanks for the review,
German