Re: [PATCH v2 0/3] Use BPF filters for a "perf top -u" workaround

[Namhyung Kim]

On Mon, May 20, 2024 at 6:04 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> Allow uid and gid to be terms in BPF filters by first breaking the
> connection between filter terms and PERF_SAMPLE_xx values. Calculate
> the uid and gid using the bpf_get_current_uid_gid helper, rather than
> from a value in the sample. Allow filters to be passed to perf top, this allows:
>
> $ perf top -e cycles:P --filter "uid == $(id -u)"
>
> to work as a "perf top -u" workaround, as "perf top -u" usually fails
> due to processes/threads terminating between the /proc scan and the
> perf_event_open.
>
> v2. Allow PERF_SAMPLE_xx to be computed from the PBF_TERM_xx value
>     using a shift as requested by Namhyung.
>
> Ian Rogers (3):
>   perf bpf filter: Give terms their own enum
>   perf bpf filter: Add uid and gid terms
>   perf top: Allow filters on events

Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>

Thanks,
Namhyung

>
>  tools/perf/Documentation/perf-record.txt     |  2 +-
>  tools/perf/Documentation/perf-top.txt        |  4 ++
>  tools/perf/builtin-top.c                     |  9 +++
>  tools/perf/util/bpf-filter.c                 | 33 ++++++----
>  tools/perf/util/bpf-filter.h                 |  5 +-
>  tools/perf/util/bpf-filter.l                 | 66 ++++++++++----------
>  tools/perf/util/bpf-filter.y                 |  7 ++-
>  tools/perf/util/bpf_skel/sample-filter.h     | 61 +++++++++++++++++-
>  tools/perf/util/bpf_skel/sample_filter.bpf.c | 54 +++++++++++-----
>  9 files changed, 171 insertions(+), 70 deletions(-)
>
> --
> 2.45.0.rc1.225.g2a3ae87e7f-goog
>