[PATCH 20/20] perf sched: No need to keep the session around

From: Arnaldo Carvalho de Melo
Date: Mon Mar 02 2015 - 22:27:51 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

We were keeping the session around just because we kept pointers to
struct thread instances, but now we reference count them, so no need
for deferring the perf_session__delete call to after we traverse the
work_list entries.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Don Zickus <dzickus@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-9agtck6jdr3rebdp39z1lo0e@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-sched.c | 24 ++++++++----------------
1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index e00e2eaf89da..a3ebf1d3c29d 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1439,8 +1439,7 @@ static int perf_sched__process_tracepoint_sample(struct perf_tool *tool __maybe_
return err;
}

-static int perf_sched__read_events(struct perf_sched *sched,
- struct perf_session **psession)
+static int perf_sched__read_events(struct perf_sched *sched)
{
const struct perf_evsel_str_handler handlers[] = {
{ "sched:sched_switch", process_sched_switch_event, },
@@ -1454,6 +1453,7 @@ static int perf_sched__read_events(struct perf_sched *sched,
.path = input_name,
.mode = PERF_DATA_MODE_READ,
};
+ int rc = -1;

session = perf_session__new(&file, false, &sched->tool);
if (session == NULL) {
@@ -1478,16 +1478,10 @@ static int perf_sched__read_events(struct perf_sched *sched,
sched->nr_lost_chunks = session->evlist->stats.nr_events[PERF_RECORD_LOST];
}

- if (psession)
- *psession = session;
- else
- perf_session__delete(session);
-
- return 0;
-
+ rc = 0;
out_delete:
perf_session__delete(session);
- return -1;
+ return rc;
}

static void print_bad_events(struct perf_sched *sched)
@@ -1515,12 +1509,10 @@ static void print_bad_events(struct perf_sched *sched)
static int perf_sched__lat(struct perf_sched *sched)
{
struct rb_node *next;
- struct perf_session *session;

setup_pager();

- /* save session -- references to threads are held in work_list */
- if (perf_sched__read_events(sched, &session))
+ if (perf_sched__read_events(sched))
return -1;

perf_sched__sort_lat(sched);
@@ -1537,6 +1529,7 @@ static int perf_sched__lat(struct perf_sched *sched)
work_list = rb_entry(next, struct work_atoms, node);
output_lat_thread(sched, work_list);
next = rb_next(next);
+ thread__zput(work_list->thread);
}

printf(" -----------------------------------------------------------------------------------------------------------------\n");
@@ -1548,7 +1541,6 @@ static int perf_sched__lat(struct perf_sched *sched)
print_bad_events(sched);
printf("\n");

- perf_session__delete(session);
return 0;
}

@@ -1557,7 +1549,7 @@ static int perf_sched__map(struct perf_sched *sched)
sched->max_cpu = sysconf(_SC_NPROCESSORS_CONF);

setup_pager();
- if (perf_sched__read_events(sched, NULL))
+ if (perf_sched__read_events(sched))
return -1;
print_bad_events(sched);
return 0;
@@ -1572,7 +1564,7 @@ static int perf_sched__replay(struct perf_sched *sched)

test_calibrations(sched);

- if (perf_sched__read_events(sched, NULL))
+ if (perf_sched__read_events(sched))
return -1;

printf("nr_run_events: %ld\n", sched->nr_run_events);
--
1.9.3

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