Re: [RFC PATCH v1 23/37] perf evsel: move bpf_counter__install_pe to success path in evsel__open_cpu

From: Arnaldo Carvalho de Melo
Date: Tue Aug 31 2021 - 15:50:30 EST


Em Sat, Aug 21, 2021 at 11:19:29AM +0200, Riccardo Mancini escreveu:
> I don't see why bpf_counter__install_pe should get called even if fd=-1,
> so I'm moving it to the success path.
>
> This will be useful in following patches to separate the actual open and
> the related operations from the fallback mechanisms.

Looks sane, applied.

Next time please use git blame to find the author and add him to the CC
list, like I just did, so that the mistery can be unveiled or a duh!
uttered :-)

- Arnaldo

> Signed-off-by: Riccardo Mancini <rickyman7@xxxxxxxxx>
> ---
> tools/perf/util/evsel.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index d2b0391569286080..3e556afed8dd396c 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -2009,8 +2009,6 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
>
> FD(evsel, cpu, thread) = fd;
>
> - bpf_counter__install_pe(evsel, cpu, fd);
> -
> if (fd < 0) {
> err = -errno;
>
> @@ -2019,6 +2017,8 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
> goto try_fallback;
> }
>
> + bpf_counter__install_pe(evsel, cpu, fd);
> +
> if (unlikely(test_attr__enabled)) {
> test_attr__open(&evsel->core.attr, pid, cpus->map[cpu],
> fd, group_fd, evsel->open_flags);
> --
> 2.31.1

--

- Arnaldo