Messages in this thread Patch in this message | | | Date | Wed, 29 Dec 2021 23:19:42 -0800 | Subject | [PATCH v3 01/48] libperf: Add comments to perf_cpu_map. | From | Ian Rogers <> |
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A particular observed problem is confusing the index with the CPU value, documentation should hopefully reduce this type of problem.
Reviewed-by: James Clark <james.clark@arm.com> Signed-off-by: Ian Rogers <irogers@google.com> --- tools/lib/perf/include/internal/cpumap.h | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/tools/lib/perf/include/internal/cpumap.h b/tools/lib/perf/include/internal/cpumap.h index 840d4032587b..4054169c12c5 100644 --- a/tools/lib/perf/include/internal/cpumap.h +++ b/tools/lib/perf/include/internal/cpumap.h @@ -4,9 +4,18 @@ #include <linux/refcount.h> +/** + * A sized, reference counted, sorted array of integers representing CPU + * numbers. This is commonly used to capture which CPUs a PMU is associated + * with. The indices into the cpumap are frequently used as they avoid having + * gaps if CPU numbers were used. For events associated with a pid, rather than + * a CPU, a single dummy map with an entry of -1 is used. + */ struct perf_cpu_map { refcount_t refcnt; + /** Length of the map array. */ int nr; + /** The CPU values. */ int map[]; }; -- 2.34.1.448.ga2b2bfdf31-goog
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