lkml.org 
[lkml]   [2022]   [Jun]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v4 3/5] perf arch events: riscv arch std event files
On Fri, Jun 24, 2022 at 9:01 AM Nikita Shubin <nikita.shubin@maquefel.me> wrote:
>
> From: Nikita Shubin <n.shubin@yadro.com>
>
> cycles, time and instret counters are defined by RISC-V privileged
> spec and they should be available on any RISC-V implementation, epose them
> to arch std event files, so they can be reused by particular PMU
> bindings.
>
> Derived-from-code-by: João Mário Domingos <joao.mario@tecnico.ulisboa.pt>
> Signed-off-by: Nikita Shubin <n.shubin@yadro.com>

Why do we need this ? The PMU driver already parses the standard perf events.
So you can pass -e cycles -e instructions.

Even though time is described as a counter and accessibility
controlled by mcounteren, you can not start/stop it (no bit in
mcountinhibit).
Thus, it can't be used from perf.

> ---
> .../pmu-events/arch/riscv/riscv-generic.json | 20 +++++++++++++++++++
> 1 file changed, 20 insertions(+)
> create mode 100644 tools/perf/pmu-events/arch/riscv/riscv-generic.json
>
> diff --git a/tools/perf/pmu-events/arch/riscv/riscv-generic.json b/tools/perf/pmu-events/arch/riscv/riscv-generic.json
> new file mode 100644
> index 000000000000..a7ffbe87a0f7
> --- /dev/null
> +++ b/tools/perf/pmu-events/arch/riscv/riscv-generic.json
> @@ -0,0 +1,20 @@
> +[
> + {
> + "PublicDescription": "CPU Cycles",
> + "EventCode": "0x00",
> + "EventName": "riscv_cycles",
> + "BriefDescription": "CPU cycles RISC-V generic counter"
> + },
> + {
> + "PublicDescription": "CPU Time",
> + "EventCode": "0x01",
> + "EventName": "riscv_time",
> + "BriefDescription": "CPU time RISC-V generic counter"
> + },
> + {
> + "PublicDescription": "CPU Instructions",
> + "EventCode": "0x02",
> + "EventName": "riscv_instret",
> + "BriefDescription": "CPU retired instructions RISC-V generic counter"
> + }
> +]
> --
> 2.35.1
>


--
Regards,
Atish

\
 
 \ /
  Last update: 2022-06-24 19:04    [W:0.162 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site