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Message-Id: <20250506164740.1317237-1-kan.liang@linux.intel.com>
Date: Tue, 6 May 2025 09:47:25 -0700
From: kan.liang@...ux.intel.com
To: peterz@...radead.org,
mingo@...hat.com,
namhyung@...nel.org,
irogers@...gle.com,
mark.rutland@....com,
linux-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org
Cc: eranian@...gle.com,
ctshao@...gle.com,
tmricht@...ux.ibm.com,
Kan Liang <kan.liang@...ux.intel.com>
Subject: [RFC PATCH 00/15] perf: Fix the throttle logic for group
From: Kan Liang <kan.liang@...ux.intel.com>
The sampling read doesn't work well with a group.
The issue was originally found by the 'Basic leader sampling test' case
failed on s390.
https://lore.kernel.org/all/20250228062241.303309-1-tmricht@linux.ibm.com/
Stephane debugged it and found it was caused by the throttling logic.
https://lore.kernel.org/all/CABPqkBQzCMNS_PfLZBWVuX9o8Z55PovwJvpVWMWzyeExFJ5R4Q@mail.gmail.com/
The throttle logic is generic and shared by all ARCHs.
It also impacts other ARCHs, e.g., X86.
On an Intel GNR machine,
$ perf record -e "{cycles,cycles}:S" ...
$ perf report -D | grep THROTTLE | tail -2
THROTTLE events: 426 ( 9.0%)
UNTHROTTLE events: 425 ( 9.0%)
$ perf report -D | grep PERF_RECORD_SAMPLE -a4 | tail -n 5
0 1020120874009167 0x74970 [0x68]: PERF_RECORD_SAMPLE(IP, 0x1):
... sample_read:
.... group nr 2
..... id 0000000000000327, value 000000000cbb993a, lost 0
..... id 0000000000000328, value 00000002211c26df, lost 0
The patch set tries to provide a generic fix for the group throttle
support. So the buggy driver-specific implementation can be removed.
The patch set is only verified on newer Intel platforms.
Kan Liang (15):
perf: Fix the throttle logic for a group
perf/x86/intel: Remove driver-specific throttle support
perf/x86/amd: Remove driver-specific throttle support
perf/x86/zhaoxin: Remove driver-specific throttle support
powerpc/perf: Remove driver-specific throttle support
s390/perf: Remove driver-specific throttle support
perf/arm: Remove driver-specific throttle support
perf/apple_m1: Remove driver-specific throttle support
alpha/perf: Remove driver-specific throttle support
arc/perf: Remove driver-specific throttle support
csky/perf: Remove driver-specific throttle support
loongarch/perf: Remove driver-specific throttle support
sparc/perf: Remove driver-specific throttle support
xtensa/perf: Remove driver-specific throttle support
mips/perf: Remove driver-specific throttle support
arch/alpha/kernel/perf_event.c | 11 ++----
arch/arc/kernel/perf_event.c | 6 +--
arch/csky/kernel/perf_event.c | 3 +-
arch/loongarch/kernel/perf_event.c | 3 +-
arch/mips/kernel/perf_event_mipsxx.c | 3 +-
arch/powerpc/perf/core-book3s.c | 6 +--
arch/powerpc/perf/core-fsl-emb.c | 3 +-
arch/s390/kernel/perf_cpum_cf.c | 2 -
arch/s390/kernel/perf_cpum_sf.c | 5 +--
arch/sparc/kernel/perf_event.c | 3 +-
arch/x86/events/amd/core.c | 3 +-
arch/x86/events/amd/ibs.c | 4 +-
arch/x86/events/core.c | 3 +-
arch/x86/events/intel/core.c | 6 +--
arch/x86/events/intel/ds.c | 7 ++--
arch/x86/events/intel/knc.c | 3 +-
arch/x86/events/intel/p4.c | 3 +-
arch/x86/events/zhaoxin/core.c | 3 +-
arch/xtensa/kernel/perf_event.c | 3 +-
drivers/perf/apple_m1_cpu_pmu.c | 3 +-
drivers/perf/arm_pmuv3.c | 3 +-
drivers/perf/arm_v6_pmu.c | 3 +-
drivers/perf/arm_v7_pmu.c | 3 +-
drivers/perf/arm_xscale_pmu.c | 6 +--
kernel/events/core.c | 55 +++++++++++++++++++++-------
25 files changed, 72 insertions(+), 81 deletions(-)
--
2.38.1
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