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charset="UTF-8" In dsos__findnew_id(), try finding the DSO under the read lock first and only acquire the write lock when a new DSO must be inserted or an existing DSO needs its ID updated (checked via dso__needs_improve_id()). Signed-off-by: Ian Rogers --- tools/perf/util/dso.c | 16 +++++++++++++++- tools/perf/util/dso.h | 1 + tools/perf/util/dsos.c | 10 ++++++++++ 3 files changed, 26 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index f0e02062c09c..4dc518f7cb7d 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -1685,6 +1685,18 @@ const struct dso_id dso_id_empty = { } }; +bool dso__needs_improve_id(const struct dso *dso, const struct dso_id *id) +{ + const struct dso_id *dso_id = dso__id_const(dso); + + if (!id) + return false; + + return (id->mmap2_valid && !dso_id->mmap2_valid) || + (id->mmap2_ino_generation_valid && !dso_id->mmap2_ino_generation_valid) || + (build_id__is_defined(&id->build_id) && !build_id__is_defined(&dso_id->build_id)); +} + void __dso__improve_id(struct dso *dso, const struct dso_id *id) { struct dsos *dsos = dso__dsos(dso); @@ -1692,6 +1704,8 @@ void __dso__improve_id(struct dso *dso, const struct dso_id *id) bool changed = false; /* dsos write lock held by caller. */ + if (!id) + return; if (id->mmap2_valid && !dso_id->mmap2_valid) { dso_id->maj = id->maj; @@ -1715,7 +1729,7 @@ void __dso__improve_id(struct dso *dso, const struct dso_id *id) int dso_id__cmp(const struct dso_id *a, const struct dso_id *b) { - if (a == &dso_id_empty || b == &dso_id_empty) { + if (!a || !b || a == &dso_id_empty || b == &dso_id_empty) { /* There is no valid data to compare so the comparison always returns identical. */ return 0; } diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h index 9f026ccb0eb6..394960cd2004 100644 --- a/tools/perf/util/dso.h +++ b/tools/perf/util/dso.h @@ -802,6 +802,7 @@ void dso__delete(struct dso *dso); int dso__cmp_id(struct dso *a, struct dso *b); void dso__set_short_name(struct dso *dso, const char *name, bool name_allocated); void dso__set_long_name(struct dso *dso, const char *name, bool name_allocated); +bool dso__needs_improve_id(const struct dso *dso, const struct dso_id *id); void __dso__improve_id(struct dso *dso, const struct dso_id *id); int dso__name_len(const struct dso *dso); diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c index 2df0ce58421e..ff58ac2566cf 100644 --- a/tools/perf/util/dsos.c +++ b/tools/perf/util/dsos.c @@ -348,6 +348,16 @@ static struct dso *__dsos__findnew_id(struct dsos *dsos, const char *name, const struct dso *dsos__findnew_id(struct dsos *dsos, const char *name, const struct dso_id *id) { struct dso *dso; + + down_read(&dsos->lock); + dso = __dsos__find_id(dsos, name, id, false, /*write_locked=*/false); + if (dso && !dso__needs_improve_id(dso, id)) { + up_read(&dsos->lock); + return dso; + } + up_read(&dsos->lock); + dso__put(dso); + down_write(&dsos->lock); dso = __dsos__findnew_id(dsos, name, id); up_write(&dsos->lock); -- 2.56.0.307.g5fe7bd680c-goog