[PATCH] D94395: [X86] AMD Znver3 Scheduler descriptions and llvm-mca tests

Wed Jan 27 04:32:43 PST 2021

ketling added a comment.

Hi,
I have the CPU (5900x) and I can help you to run some commands if you tell me exactly what to do.

There is a small catch right now that libpfm does not support Zen3 performance counters yet. So as a result llvm-exegesis throws the error "event not found - cannot create event cycles_not_in_halt" and fails. One has to patch/compile/install libpfm first. My simple stupid patch for libpfm below.

  diff -uNr libpfm-4.11.0/lib/pfmlib_amd64.c libpfm-4.11.0.p/lib/pfmlib_amd64.c
  --- libpfm-4.11.0/lib/pfmlib_amd64.c	2020-09-02 20:48:00.000000000 +0200
  +++ libpfm-4.11.0.p/lib/pfmlib_amd64.c	2021-01-27 12:50:10.536351642 +0100
  @@ -183,6 +183,8 @@
                   }
   	} else if (cfg->family == 22) { /* family 16h */
   		rev = PFM_PMU_AMD64_FAM16H;
  +	} else if (cfg->family == 25) { /* family 19h */
  +		rev = PFM_PMU_AMD64_FAM17H_ZEN2;
   	}

         cfg->revision = rev;

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D94395/new/

https://reviews.llvm.org/D94395