Add 'overwrite' attribute to evsel to mark whether this event is set overwritable. Following commits will support syntax like # perf record -e cycles/overwrite/ ...
Overwritable evsel require kernel support write_backward. Add it to perf_missing_feature. Signed-off-by: Wang Nan <[email protected]> Cc: He Kuang <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Zefan Li <[email protected]> Cc: [email protected] --- tools/perf/util/evsel.c | 13 +++++++++++++ tools/perf/util/evsel.h | 1 + 2 files changed, 14 insertions(+) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index a23f547..ed74ae4 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -37,6 +37,7 @@ static struct { bool clockid; bool clockid_wrong; bool lbr_flags; + bool write_backward; } perf_missing_features; static clockid_t clockid; @@ -1376,6 +1377,8 @@ fallback_missing_features: if (perf_missing_features.lbr_flags) evsel->attr.branch_sample_type &= ~(PERF_SAMPLE_BRANCH_NO_FLAGS | PERF_SAMPLE_BRANCH_NO_CYCLES); + if (perf_missing_features.write_backward) + evsel->attr.write_backward = false; retry_sample_id: if (perf_missing_features.sample_id_all) evsel->attr.sample_id_all = 0; @@ -1438,6 +1441,12 @@ retry_open: err = -EINVAL; goto out_close; } + + if (evsel->overwrite && + perf_missing_features.write_backward) { + err = -EINVAL; + goto out_close; + } } } @@ -1500,6 +1509,10 @@ try_fallback: PERF_SAMPLE_BRANCH_NO_FLAGS))) { perf_missing_features.lbr_flags = true; goto fallback_missing_features; + } else if (!perf_missing_features.write_backward && + evsel->attr.write_backward) { + perf_missing_features.write_backward = true; + goto fallback_missing_features; } out_close: diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index 8a644fe..c1f1015 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -112,6 +112,7 @@ struct perf_evsel { bool tracking; bool per_pkg; bool precise_max; + bool overwrite; /* parse modifier helper */ int exclude_GH; int nr_members; -- 1.8.3.4
