Re: [PATCH v8 1/9] perf pmu: Add #slots literal support for arm64

John Garry
2023-01-17T08:46:17Z

On 17/01/2023 07:29, Jing Zhang wrote:
> The slots in each architecture may be different, so add #slots literal
> to obtain the slots of different architectures, and the #slots can be
> applied in the metric. Currently, The #slots just support for arm64,
> and other architectures will return NAN.
>
> On arm64, the value of slots is from the register PMMIR_EL1.SLOT, which
> I can read in /sys/bus/event_source/device/armv8_pmuv3_*/caps/slots.
> PMMIR_EL1.SLOT might read as zero if the PMU version is lower than
> ID_AA64DFR0_EL1_PMUVer_V3P4 or the STALL_SLOT event is not implemented.
>
> Signed-off-by: Jing Zhang<renyu.zj@linux.alibaba.com>