[PATCH AUTOSEL 3.18 44/98] perf/x86/intel: Fix bug for "cycles:p" and "cycles:pp" on SLM

From: Sasha Levin
Date: Thu Oct 25 2018 - 10:26:04 EST

From: Kan Liang <kan.liang@xxxxxxxxx>

[ Upstream commit 33636732dcd7cc738a5913bb730d663c6b03c8fb ]

cycles:p and cycles:pp do not work on SLM since commit:

86a04461a99f ("perf/x86: Revamp PEBS event selection")

UOPS_RETIRED.ALL is not a PEBS capable event, so it should not be used
to count cycle number.

Actually SLM calls intel_pebs_aliases_core2() which uses INST_RETIRED.ANY_P
to count the number of cycles. It's a PEBS capable event. But inv and
cmask must be set to count cycles.

Considering SLM allows all events as PEBS with no flags, only
INST_RETIRED.ANY_P, inv=1, cmask=16 needs to handled specially.

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1421084541-31639-1-git-send-email-kan.liang@xxxxxxxxx
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
arch/x86/kernel/cpu/perf_event_intel_ds.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 46211bcc813e..423cbd9bea3e 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -568,8 +568,8 @@ struct event_constraint intel_atom_pebs_event_constraints[] = {

struct event_constraint intel_slm_pebs_event_constraints[] = {
- /* UOPS_RETIRED.ALL, inv=1, cmask=16 (cycles:p). */
+ /* INST_RETIRED.ANY_P, inv=1, cmask=16 (cycles:p). */
/* Allow all events as PEBS with no flags */