[PATCH v4 0/3] Assorted fixes in RISC-V PMU driver
Atish Patra
atishp at rivosinc.com
Fri Jun 28 00:51:40 PDT 2024
This series contains 3 fixes out of which the first one is a new fix
for invalid event data reported in lkml[2]. The last two are v3 of Samuel's
patch[1]. I added the RB/TB/Fixes tag and moved 1 unrelated change
to its own patch. I also changed an error message in kvm vcpu_pmu from
pr_err to pr_debug to avoid redundant failure error messages generated
due to the boot time quering of events implemented in the patch[1]
Here is the original cover letter for the patch[1]
Before this patch:
$ perf list hw
List of pre-defined events (to be used in -e or -M):
branch-instructions OR branches [Hardware event]
branch-misses [Hardware event]
bus-cycles [Hardware event]
cache-misses [Hardware event]
cache-references [Hardware event]
cpu-cycles OR cycles [Hardware event]
instructions [Hardware event]
ref-cycles [Hardware event]
stalled-cycles-backend OR idle-cycles-backend [Hardware event]
stalled-cycles-frontend OR idle-cycles-frontend [Hardware event]
$ perf stat -ddd true
Performance counter stats for 'true':
4.36 msec task-clock # 0.744 CPUs utilized
1 context-switches # 229.325 /sec
0 cpu-migrations # 0.000 /sec
38 page-faults # 8.714 K/sec
4,375,694 cycles # 1.003 GHz (60.64%)
728,945 instructions # 0.17 insn per cycle
79,199 branches # 18.162 M/sec
17,709 branch-misses # 22.36% of all branches
181,734 L1-dcache-loads # 41.676 M/sec
5,547 L1-dcache-load-misses # 3.05% of all L1-dcache accesses
<not counted> LLC-loads (0.00%)
<not counted> LLC-load-misses (0.00%)
<not counted> L1-icache-loads (0.00%)
<not counted> L1-icache-load-misses (0.00%)
<not counted> dTLB-loads (0.00%)
<not counted> dTLB-load-misses (0.00%)
<not counted> iTLB-loads (0.00%)
<not counted> iTLB-load-misses (0.00%)
<not counted> L1-dcache-prefetches (0.00%)
<not counted> L1-dcache-prefetch-misses (0.00%)
0.005860375 seconds time elapsed
0.000000000 seconds user
0.010383000 seconds sys
After this patch:
$ perf list hw
List of pre-defined events (to be used in -e or -M):
branch-instructions OR branches [Hardware event]
branch-misses [Hardware event]
cache-misses [Hardware event]
cache-references [Hardware event]
cpu-cycles OR cycles [Hardware event]
instructions [Hardware event]
$ perf stat -ddd true
Performance counter stats for 'true':
5.16 msec task-clock # 0.848 CPUs utilized
1 context-switches # 193.817 /sec
0 cpu-migrations # 0.000 /sec
37 page-faults # 7.171 K/sec
5,183,625 cycles # 1.005 GHz
961,696 instructions # 0.19 insn per cycle
85,853 branches # 16.640 M/sec
20,462 branch-misses # 23.83% of all branches
243,545 L1-dcache-loads # 47.203 M/sec
5,974 L1-dcache-load-misses # 2.45% of all L1-dcache accesses
<not supported> LLC-loads
<not supported> LLC-load-misses
<not supported> L1-icache-loads
<not supported> L1-icache-load-misses
<not supported> dTLB-loads
19,619 dTLB-load-misses
<not supported> iTLB-loads
6,831 iTLB-load-misses
<not supported> L1-dcache-prefetches
<not supported> L1-dcache-prefetch-misses
0.006085625 seconds time elapsed
0.000000000 seconds user
0.013022000 seconds sys
Changes in v4:
- Added SoB tags.
- Improved the commit message in patch 1
- Link to v3: https://lore.kernel.org/r/20240626-misc_perf_fixes-v3-0-de3f8ed88dab@rivosinc.com
Changes in v3:
- Added one more fix
- Separated an unrelated change to its own patch.
- Rebase and Added RB/TB/Fixes tag.
- Changed a error message in kvm code to avoid unnecessary failures
at guest booting.
Changes in v2:
- Move the event checking to a workqueue to make it asynchronous
- Add more details to the commit message based on the v1 discussion
[1] https://lore.kernel.org/linux-riscv/20240418014652.1143466-1-samuel.holland@sifive.com/
[2] https://lore.kernel.org/all/CC51D53B-846C-4D81-86FC-FBF969D0A0D6@pku.edu.cn/
Signed-off-by: Atish Patra <atishp at rivosinc.com>
---
Atish Patra (1):
drivers/perf: riscv: Do not update the event data if uptodate
Samuel Holland (2):
drivers/perf: riscv: Reset the counter to hpmevent mapping while starting cpus
perf: RISC-V: Check standard event availability
arch/riscv/kvm/vcpu_pmu.c | 2 +-
drivers/perf/riscv_pmu.c | 2 +-
drivers/perf/riscv_pmu_sbi.c | 44 +++++++++++++++++++++++++++++++++++++++++---
3 files changed, 43 insertions(+), 5 deletions(-)
---
base-commit: 55027e689933ba2e64f3d245fb1ff185b3e7fc81
change-id: 20240625-misc_perf_fixes-5c57f555d828
--
Regards,
Atish patra
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