Re: [PATCH 10/26] perf tools: Enable mmap3 map event when supported

Arnaldo Carvalho de Melo
2020-09-14T16:16:39Z

Em Sun, Sep 13, 2020 at 11:02:57PM +0200, Jiri Olsa escreveu:
> Enabling mmap3 map event when supported and adding
> its disable fallback when it fails.
>
> Also adding mmap3 bit to verbose open output:

This should check if the user disabled build id collection, i.e. if its
not something the user is interest on.

- Arnaldo

> $ perf record -vv kill
> perf_event_attr:
> size 120
> { sample_period, sample_freq } 4000
> ...
> bpf_event 1
> mmap3 1
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> tools/perf/util/evsel.c | 9 ++++++++-
> tools/perf/util/evsel.h | 1 +
> tools/perf/util/perf_event_attr_fprintf.c | 1 +
> 3 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 14baf8542b40..c2cc9b4b30bf 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -1065,6 +1065,7 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
> attr->task = track;
> attr->mmap = track;
> attr->mmap2 = track && !perf_missing_features.mmap2;
> + attr->mmap3 = track && !perf_missing_features.mmap3;
> attr->comm = track;
> /*
> * ksymbol is tracked separately with text poke because it needs to be
> @@ -1657,6 +1658,8 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
> evsel->core.attr.bpf_event = 0;
> if (perf_missing_features.branch_hw_idx)
> evsel->core.attr.branch_sample_type &= ~PERF_SAMPLE_BRANCH_HW_INDEX;
> + if (perf_missing_features.mmap3)
> + evsel->core.attr.mmap3 = 0;
> retry_sample_id:
> if (perf_missing_features.sample_id_all)
> evsel->core.attr.sample_id_all = 0;
> @@ -1770,7 +1773,11 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
> * Must probe features in the order they were added to the
> * perf_event_attr interface.
> */
> - if (!perf_missing_features.cgroup && evsel->core.attr.cgroup) {
> + if (!perf_missing_features.mmap3 && evsel->core.attr.mmap3) {
> + perf_missing_features.mmap3 = true;
> + pr_debug2("switching off mmap3\n");
> + goto fallback_missing_features;
> + } else if (!perf_missing_features.cgroup && evsel->core.attr.cgroup) {
> perf_missing_features.cgroup = true;
> pr_debug2_peo("Kernel has no cgroup sampling support, bailing out\n");
> goto out_close;
> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> index 35e3f6d66085..d49922b22eca 100644
> --- a/tools/perf/util/evsel.h
> +++ b/tools/perf/util/evsel.h
> @@ -119,6 +119,7 @@ struct perf_missing_features {
> bool sample_id_all;
> bool exclude_guest;
> bool mmap2;
> + bool mmap3;
> bool cloexec;
> bool clockid;
> bool clockid_wrong;
> diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c
> index e67a227c0ce7..3c52c081693d 100644
> --- a/tools/perf/util/perf_event_attr_fprintf.c
> +++ b/tools/perf/util/perf_event_attr_fprintf.c
> @@ -134,6 +134,7 @@ int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
> PRINT_ATTRf(bpf_event, p_unsigned);
> PRINT_ATTRf(aux_output, p_unsigned);
> PRINT_ATTRf(cgroup, p_unsigned);
> + PRINT_ATTRf(mmap3, p_unsigned);
>
> PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned);
> PRINT_ATTRf(bp_type, p_unsigned);
> --
> 2.26.2
>

--

- Arnaldo