Re: [PATCH] perf/x86/intel/ds: fix precise store latency handling

From: Peter Zijlstra
Date: Thu Aug 18 2022 - 04:36:55 EST


On Wed, Aug 17, 2022 at 10:46:13PM -0700, Stephane Eranian wrote:
> With the existing code in store_latency_data(), the memory operation (mem_op)
> returned to the user is always OP_LOAD where in fact, it should be OP_STORE.
> This comes from the fact that the function is simply grabbing the information
> from a data source map which covers only load accesses. Intel 12th gen CPU
> offers precise store sampling that captures both the data source and latency.
> Therefore it can use the data source mapping table but must override the
> memory operation to reflect stores instead of loads.
>
> Fixes: 61b985e3e775 ("perf/x86/intel: Add perf core PMU support for Sapphire Rapids")
> Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>

Thanks