[PATCH 11/20] perf header: Add HEADER_GROUP_DESC feature

Namhyung Kim
2012-10-04T12:54:31Z

From: Namhyung Kim <namhyung.kim@lge.com>

Save group relationship information so that it can be restored when
perf report is running.

Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/builtin-record.c | 3 +
tools/perf/util/header.c | 152 +++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/header.h | 2 +
3 files changed, 157 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 8c029fe2e22c..7940f0dd3db9 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -558,6 +558,9 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv)
goto out_delete_session;
}

+ if (!evsel_list->nr_groups)
+ perf_header__clear_feat(&session->header, HEADER_GROUP_DESC);
+
/*
* perf_session__delete(session) will be called at perf_record__exit()
*/
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 7daad237dea5..caceb33d8d1b 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1072,6 +1072,41 @@ static int write_pmu_mappings(int fd, struct perf_header *h __maybe_unused,
}

/*
+ * File format:
+ *
+ * struct group_descs {
+ * u32 nr_groups;
+ * struct group_desc {
+ * char name[];
+ * u32 leader_idx;
+ * u32 nr_members;
+ * }[nr_groups];
+ * };
+ */
+static int write_group_desc(int fd, struct perf_header *h __maybe_unused,
+ struct perf_evlist *evlist)
+{
+ u32 nr_groups = evlist->nr_groups;
+ struct perf_evsel *evsel;
+
+ do_write(fd, &nr_groups, sizeof(nr_groups));
+
+ list_for_each_entry(evsel, &evlist->entries, node) {
+ if (perf_evsel__is_group_leader(evsel) &&
+ evsel->nr_members > 0) {
+ const char *name = evsel->group_name ?: "{anon_group}";
+ u32 leader_idx = evsel->idx;
+ u32 nr_members = evsel->nr_members;
+
+ do_write_string(fd, name);
+ do_write(fd, &leader_idx, sizeof(leader_idx));
+ do_write(fd, &nr_members, sizeof(nr_members));
+ }
+ }
+ return 0;
+}
+
+/*
* default get_cpuid(): nothing gets recorded
* actual implementation must be in arch/$(ARCH)/util/header.c
*/
@@ -1432,6 +1467,31 @@ error:
fprintf(fp, "# pmu mappings: unable to read\n");
}

+static void print_group_desc(struct perf_header *ph, int fd __maybe_unused,
+ FILE *fp)
+{
+ struct perf_session *session;
+ struct perf_evsel *evsel;
+ u32 nr = 0;
+
+ session = container_of(ph, struct perf_session, header);
+
+ list_for_each_entry(evsel, &session->evlist->entries, node) {
+ if (perf_evsel__is_group_leader(evsel) &&
+ evsel->nr_members > 0) {
+ fprintf(fp, "# group: %s{%s", evsel->group_name ?: "",
+ perf_evsel__name(evsel));
+
+ nr = evsel->nr_members;
+ } else if (nr) {
+ fprintf(fp, ",%s", perf_evsel__name(evsel));
+
+ if (--nr == 0)
+ fprintf(fp, "}\n");
+ }
+ }
+}
+
static int __event_process_build_id(struct build_id_event *bev,
char *filename,
struct perf_session *session)
@@ -1946,6 +2006,97 @@ error:
return -1;
}

+static int process_group_desc(struct perf_file_section *section __maybe_unused,
+ struct perf_header *ph, int fd,
+ void *data __maybe_unused)
+{
+ size_t ret = -1;
+ u32 i, nr, nr_groups;
+ struct perf_session *session;
+ struct perf_evsel *evsel, *leader;
+ struct group_desc {
+ char *name;
+ u32 leader_idx;
+ u32 nr_members;
+ } *desc;
+
+ ret = read(fd, &nr_groups, sizeof(nr_groups));
+ if (ret != sizeof(nr_groups))
+ return -1;
+
+ if (ph->needs_swap)
+ nr_groups = bswap_32(nr_groups);
+
+ ph->env.nr_groups = nr_groups;
+ if (!nr_groups) {
+ pr_debug("group desc not available\n");
+ return 0;
+ }
+
+ desc = calloc(nr_groups, sizeof(*desc));
+ if (!desc)
+ return -1;
+
+ for (i = 0; i < nr_groups; i++) {
+ desc[i].name = do_read_string(fd, ph);
+ if (!desc[i].name)
+ goto out_free;
+
+ ret = read(fd, &desc[i].leader_idx, sizeof(u32));
+ if (ret != sizeof(u32))
+ goto out_free;
+
+ ret = read(fd, &desc[i].nr_members, sizeof(u32));
+ if (ret != sizeof(u32))
+ goto out_free;
+
+ if (ph->needs_swap) {
+ desc[i].leader_idx = bswap_32(desc[i].leader_idx);
+ desc[i].nr_members = bswap_32(desc[i].nr_members);
+ }
+ }
+
+ /*
+ * Rebuild group relationship based on the group_desc
+ */
+ session = container_of(ph, struct perf_session, header);
+ session->evlist->nr_groups = nr_groups;
+
+ i = nr = 0;
+ list_for_each_entry(evsel, &session->evlist->entries, node) {
+ if (evsel->idx == (int) desc[i].leader_idx) {
+ evsel->leader = NULL;
+ /* {anon_group} is a dummy name */
+ if (strcmp(desc[i].name, "{anon_group}"))
+ evsel->group_name = desc[i].name;
+ evsel->nr_members = desc[i].nr_members;
+
+ BUG_ON(i >= nr_groups);
+ BUG_ON(nr > 0);
+
+ leader = evsel;
+ nr = evsel->nr_members;
+ i++;
+ } else if (nr) {
+ /* This is a group member */
+ evsel->leader = leader;
+ /* group_idx starts from 0 */
+ evsel->group_idx = leader->nr_members - nr;
+ nr--;
+ }
+ }
+
+ BUG_ON(i != nr_groups);
+ BUG_ON(nr != 0);
+
+out_free:
+ while ((int) --i >= 0)
+ free(desc[i].name);
+ free(desc);
+
+ return ret;
+}
+
struct feature_ops {
int (*write)(int fd, struct perf_header *h, struct perf_evlist *evlist);
void (*print)(struct perf_header *h, int fd, FILE *fp);
@@ -1985,6 +2136,7 @@ static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
FEAT_OPF(HEADER_NUMA_TOPOLOGY, numa_topology),
FEAT_OPA(HEADER_BRANCH_STACK, branch_stack),
FEAT_OPP(HEADER_PMU_MAPPINGS, pmu_mappings),
+ FEAT_OPP(HEADER_GROUP_DESC, group_desc),
};

struct header_print_data {
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 99bdd3abce59..f143aa7153a2 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -29,6 +29,7 @@ enum {
HEADER_NUMA_TOPOLOGY,
HEADER_BRANCH_STACK,
HEADER_PMU_MAPPINGS,
+ HEADER_GROUP_DESC,
HEADER_LAST_FEATURE,
HEADER_FEAT_BITS = 256,
};
@@ -79,6 +80,7 @@ struct perf_session_env {
char *numa_nodes;
int nr_pmu_mappings;
char *pmu_mappings;
+ int nr_groups;
};

struct perf_header {
--
1.7.9.2