Re: [PATCH] perf/x86/intel: fix ICL/SPR INST_RETIRED.PREC_DIST encodings

From: Andi Kleen
Date: Wed Oct 13 2021 - 20:39:00 EST



On 10/13/2021 5:12 PM, Stephane Eranian wrote:
This patch fixes the encoding for INST_RETIRED.PREC_DIST as published by Intel
(download.01.org/perfmon/) for Icelake. The official encoding
is event code 0x00 umask 0x1, a change from Skylake where it was code 0xc0
umask 0x1.

With this patch applied it is possible to run:
$ perf record -a -e cpu/event=0x00,umask=0x1/pp .....

Whereas before this would fail.

To avoid problems with tools which may use the old code, we maintain the old
encoding for Icelake.

Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>


Make sense.

Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>


-Andi