[v3 00/10] Improve RISC-V Perf support using SBI PMU and sscofpmf extension

[Nikita Shubin]

On Fri, 10 Sep 2021 12:27:47 -0700
Atish Patra <atish.patra at wdc.com> wrote:

Hello Atish,

> Perf stat:
> =========
> 
> [root at fedora-riscv riscv]# perf stat -e r8000000000000005 -e
> r8000000000000007 -e r8000000000000006 -e r0000000000020002 -e
> r0000000000020004 -e branch-misses -e cache-misses -e
> dTLB-load-misses -e dTLB-store-misses -e iTLB-load-misses -e cycles
> -e instructions ./hackbench -pipe 15 process Running with 15*40 (==
> 600) tasks. Time: 6.578
> 
>  Performance counter stats for './hackbench -pipe 15 process':
> 
>              6,491      r8000000000000005      (52.59%) -->
> SBI_PMU_FW_SET_TIMER 20,433      r8000000000000007      (60.74%) -->
> SBI_PMU_FW_IPI_RECVD 21,271      r8000000000000006      (68.71%) -->
> SBI_PMU_FW_IPI_SENT 0      r0000000000020002      (76.55%)
>      <not counted>      r0000000000020004      (0.00%)
>      <not counted>      branch-misses          (0.00%)
>      <not counted>      cache-misses           (0.00%)
>         57,537,853      dTLB-load-misses       (9.49%)
>          2,821,147      dTLB-store-misses      (18.64%)
>         52,928,130      iTLB-load-misses       (27.53%)
>     89,521,791,110      cycles                 (36.08%)
>     90,678,132,464      instructions #    1.01  insn per cycle
> (44.44%)
> 
>        6.975908032 seconds time elapsed
> 
>        3.130950000 seconds user
>       24.353310000 seconds sys
> 

Tested your patch series with qemu and got results as expected:

perf stat -e r8000000000000005 -e r8000000000000007 \
-e r8000000000000006 -e r0000000000020002 -e r0000000000020004 -e
branch-misses \ -e cache-misses -e dTLB-load-misses -e
dTLB-store-misses -e iTLB-load-misses \ -e cycles -e instructions
./hackbench -pipe 15 process

Running with 15*40 (== 600) tasks.nch -pipe 15 process
Time: 20.027

 Performance counter stats for './hackbench -pipe 15 process':

              4896      r8000000000000005
                            (53.34%) 0      r8000000000000007
                                                (61.20%) 0
              r8000000000000006
                  (68.88%) 0      r0000000000020002
                                      (76.53%) <not counted>
              r0000000000020004
                  (0.00%) <not counted>      branch-misses
                                                 (0.00%) <not counted>
                  cache-misses
                      (0.00%) 48414917      dTLB-load-misses
                                                (9.87%) 2427413
              dTLB-store-misses
                  (19.43%) 46958092      iTLB-load-misses
                                             (28.58%) 69245163600
              cycles
                  (37.09%) 70334279943      instructions              #
                 1.02  insn per cycle           (45.24%)

      20.895871900 seconds time elapsed

       2.724942000 seconds user
      18.126277000 seconds sys

perf top/record also works.

Tested-by: Nikita Shubin <n.shubin at yadro.com>

Yours,
Nikita Shubin