This is a note to let you know that I've just added the patch titled
perf/x86/intel/uncore: Fix the scale of the IMC free-running events
to the 5.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-x86-intel-uncore-fix-the-scale-of-the-imc-free-.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 58dc1b41b65a8a973ae9f0148ff2e21058f25f13
Author: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Date: Mon Sep 28 06:32:40 2020 -0700
perf/x86/intel/uncore: Fix the scale of the IMC free-running events
[ 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@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200928133240.12977-1-kan.liang@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 */ },
};
