[PATCH 03/13] perf header: Add HEADER_GROUP_DESC feature

From: Namhyung Kim
Date: Tue Jan 15 2013 - 02:35:11 EST


From: Namhyung Kim <namhyung.kim@xxxxxxx>

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

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1355726345-29553-5-git-send-email-namhyung@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 3 +
tools/perf/util/header.c | 164 ++++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/header.h | 2 +
3 files changed, 169 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 2ac690cad411..774c90713a53 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -486,6 +486,9 @@ 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 fccd69dbbbb9..b614c9638fd5 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1082,6 +1082,52 @@ 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;
+ int ret;
+
+ ret = do_write(fd, &nr_groups, sizeof(nr_groups));
+ if (ret < 0)
+ return ret;
+
+ list_for_each_entry(evsel, &evlist->entries, node) {
+ if (perf_evsel__is_group_leader(evsel) &&
+ evsel->nr_members > 1) {
+ const char *name = evsel->group_name ?: "{anon_group}";
+ u32 leader_idx = evsel->idx;
+ u32 nr_members = evsel->nr_members;
+
+ ret = do_write_string(fd, name);
+ if (ret < 0)
+ return ret;
+
+ ret = do_write(fd, &leader_idx, sizeof(leader_idx));
+ if (ret < 0)
+ return ret;
+
+ ret = do_write(fd, &nr_members, sizeof(nr_members));
+ if (ret < 0)
+ return ret;
+ }
+ }
+ return 0;
+}
+
+/*
* default get_cpuid(): nothing gets recorded
* actual implementation must be in arch/$(ARCH)/util/header.c
*/
@@ -1444,6 +1490,31 @@ 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 > 1) {
+ fprintf(fp, "# group: %s{%s", evsel->group_name ?: "",
+ perf_evsel__name(evsel));
+
+ nr = evsel->nr_members - 1;
+ } 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)
@@ -1958,6 +2029,98 @@ 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 = NULL;
+ struct group_desc {
+ char *name;
+ u32 leader_idx;
+ u32 nr_members;
+ } *desc;
+
+ if (readn(fd, &nr_groups, sizeof(nr_groups)) != 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;
+
+ if (readn(fd, &desc[i].leader_idx, sizeof(u32)) != sizeof(u32))
+ goto out_free;
+
+ if (readn(fd, &desc[i].nr_members, sizeof(u32)) != 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 = evsel;
+ /* {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;
+
+ if (i >= nr_groups || nr > 0) {
+ pr_debug("invalid group desc\n");
+ goto out_free;
+ }
+
+ leader = evsel;
+ nr = evsel->nr_members - 1;
+ i++;
+ } else if (nr) {
+ /* This is a group member */
+ evsel->leader = leader;
+
+ nr--;
+ }
+ }
+
+ if (i != nr_groups || nr != 0) {
+ pr_debug("invalid group desc\n");
+ goto out_free;
+ }
+
+ ret = 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);
@@ -1997,6 +2160,7 @@ 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 20f0344accb1..c9fc55cada6d 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 {
--
1.7.11.7

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