Re: [PATCH v8 1/2] perf: Reveal PMU type in fdinfo

[Peter Zijlstra]

On Tue, Jun 02, 2026 at 11:13:48AM -0700, Chun-Tse Shao wrote:
> It gives useful info on knowing which PMUs are reserved by this process.
> Also add config which would be useful.
> Testing cycles:
> 
>   $ ./perf stat -e cycles &
>   $ cat /proc/`pidof perf`/fdinfo/3
>   pos:    0
>   flags:  02000002
>   mnt_id: 16
>   ino:    3081
>   perf_event_attr.type:   0
>   perf_event_attr.config: 0x0
>   perf_event_attr.config1:        0x0
>   perf_event_attr.config2:        0x0
>   perf_event_attr.config3:        0x0
>   perf_event_attr.config4:        0x0
> 
> Testing L1-dcache-load-misses:
> 
>   $ ./perf stat -e L1-dcache-load-misses &
>   $ cat /proc/`pidof perf`/fdinfo/3
>   pos:    0
>   flags:  02000002
>   mnt_id: 16
>   ino:    1072
>   perf_event_attr.type:   3
>   perf_event_attr.config: 0x10000
>   perf_event_attr.config1:        0x0
>   perf_event_attr.config2:        0x0
>   perf_event_attr.config3:        0x0
>   perf_event_attr.config4:        0x0
> 
> Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
> Signed-off-by: Chun-Tse Shao <ctshao@xxxxxxxxxx>
> Assisted-by: Gemini:gemini-3.1-pro-preview
> ---

Yeah, I suppose I'll take this. But I'm not sure about the wording here.
PMUs aren't really reserved as such.