Re: [PATCH v4 4/4] perf mem: Support HITM for when mem_lvl_num is any

Ali Saidi
2022-03-26T19:15:23Z

On Sat, 26 Mar 2022 22:23:03 +0000, Leo Yan wrote:
> On Thu, Mar 24, 2022 at 06:33:23PM +0000, Ali Saidi wrote:
> > For loads that hit in a the LLC snoop filter and are fulfilled from a
> > higher level cache on arm64 Neoverse cores, it's not usually clear what
> > the true level of the cache the data came from (i.e. a transfer from a
> > core could come from it's L1 or L2). Instead of making an assumption of
> > where the line came from, add support for incrementing HITM if the
> > source is CACHE_ANY.A
[snip]
>
> This might break the memory profiling result for x86, see file
> arch/x86/events/intel/ds.c:
>
> 97 void __init intel_pmu_pebs_data_source_skl(bool pmem)
> 98 {
> 99 u64 pmem_or_l4 = pmem ? LEVEL(PMEM) : LEVEL(L4);
> ...
> 105 pebs_data_source[0x0d] = OP_LH | LEVEL(ANY_CACHE) | REM | P(SNOOP, HITM);
> 106 }
>

Thanks for catching this Leo, I'll add your fix.

Ali