[PATCH 5.9 108/757] perf/x86/intel/uncore: Fix the scale of the IMC free-running events

Greg Kroah-Hartman
2020-10-27T15:30:32Z

From: Kan Liang <kan.liang@linux.intel.com>

[ Upstream commit 8191016a026b8dfbb14dea64efc8e723ee99fe65 ]

The "MiB" result of the IMC free-running bandwidth events,
uncore_imc_free_running/read/ and uncore_imc_free_running/write/ are 16
times too small.

The "MiB" value equals the raw IMC free-running bandwidth counter value
times a "scale" which is inaccurate.

The IMC free-running bandwidth events should be incremented per 64B
cache line, not DWs (4 bytes). The "scale" should be 6.103515625e-5.
Fix the "scale" for both Snow Ridge and Ice Lake.

Fixes: 2b3b76b5ec67 ("perf/x86/intel/uncore: Add Ice Lake server uncore support")
Fixes: ee49532b38dd ("perf/x86/intel/uncore: Add IMC uncore support for Snow Ridge")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200928133240.12977-1-kan.liang@linux.intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/events/intel/uncore_snbep.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index ccfa1d6b6aa0d..4f5e78a4003be 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -4754,10 +4754,10 @@ static struct uncore_event_desc snr_uncore_imc_freerunning_events[] = {
INTEL_UNCORE_EVENT_DESC(dclk, "event=0xff,umask=0x10"),

INTEL_UNCORE_EVENT_DESC(read, "event=0xff,umask=0x20"),
- INTEL_UNCORE_EVENT_DESC(read.scale, "3.814697266e-6"),
+ INTEL_UNCORE_EVENT_DESC(read.scale, "6.103515625e-5"),
INTEL_UNCORE_EVENT_DESC(read.unit, "MiB"),
INTEL_UNCORE_EVENT_DESC(write, "event=0xff,umask=0x21"),
- INTEL_UNCORE_EVENT_DESC(write.scale, "3.814697266e-6"),
+ INTEL_UNCORE_EVENT_DESC(write.scale, "6.103515625e-5"),
INTEL_UNCORE_EVENT_DESC(write.unit, "MiB"),
{ /* end: all zeroes */ },
};
@@ -5215,17 +5215,17 @@ static struct uncore_event_desc icx_uncore_imc_freerunning_events[] = {
INTEL_UNCORE_EVENT_DESC(dclk, "event=0xff,umask=0x10"),

INTEL_UNCORE_EVENT_DESC(read, "event=0xff,umask=0x20"),
- INTEL_UNCORE_EVENT_DESC(read.scale, "3.814697266e-6"),
+ INTEL_UNCORE_EVENT_DESC(read.scale, "6.103515625e-5"),
INTEL_UNCORE_EVENT_DESC(read.unit, "MiB"),
INTEL_UNCORE_EVENT_DESC(write, "event=0xff,umask=0x21"),
- INTEL_UNCORE_EVENT_DESC(write.scale, "3.814697266e-6"),
+ INTEL_UNCORE_EVENT_DESC(write.scale, "6.103515625e-5"),
INTEL_UNCORE_EVENT_DESC(write.unit, "MiB"),

INTEL_UNCORE_EVENT_DESC(ddrt_read, "event=0xff,umask=0x30"),
- INTEL_UNCORE_EVENT_DESC(ddrt_read.scale, "3.814697266e-6"),
+ INTEL_UNCORE_EVENT_DESC(ddrt_read.scale, "6.103515625e-5"),
INTEL_UNCORE_EVENT_DESC(ddrt_read.unit, "MiB"),
INTEL_UNCORE_EVENT_DESC(ddrt_write, "event=0xff,umask=0x31"),
- INTEL_UNCORE_EVENT_DESC(ddrt_write.scale, "3.814697266e-6"),
+ INTEL_UNCORE_EVENT_DESC(ddrt_write.scale, "6.103515625e-5"),
INTEL_UNCORE_EVENT_DESC(ddrt_write.unit, "MiB"),
{ /* end: all zeroes */ },
};
--
2.25.1