[PATCH 18/19] perf ftrace: Show leaf-functions as oneliner

From: Namhyung Kim
Date: Wed Jun 26 2013 - 03:14:44 EST


From: Namhyung Kim <namhyung.kim@xxxxxxx>

Detect leaf functions and print them in a same line.

Note that it only converts leaf-functions that doesn't have any other
records between entry and exit even in other cpus. I left other leaf
functions as is.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/builtin-ftrace.c | 87 +++++++++++++++++++++++++++++++++++++++------
1 file changed, 76 insertions(+), 11 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 48dc54851765..f17269db3121 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -860,34 +860,77 @@ function_handler(struct trace_seq *s, struct pevent_record *record,

#define TRACE_GRAPH_INDENT 2

+static struct pevent_record *peek_ordered_record(struct perf_ftrace *ftrace);
+static struct pevent_record *get_ordered_record(struct perf_ftrace *ftrace);
+
+static struct event_format *fgraph_exit_event;
+
static int
fgraph_ent_handler(struct trace_seq *s, struct pevent_record *record,
- struct event_format *event, void *context __maybe_unused)
+ struct event_format *event, void *context)
{
unsigned long long depth;
unsigned long long val;
const char *func;
+ struct perf_ftrace *ftrace = context;
+ struct pevent_record *next;
+ bool is_leaf = false;
+ bool needs_free = false;
+ void *data;
+ int ret = -1;
int i;

+ /*
+ * record->data can be invalidated after calling peek_ordered_record()
+ * because it can unmap the current kbuffer page. Make a copy.
+ */
+ data = malloc(record->size);
+ if (data == NULL)
+ goto nested;
+
+ memcpy(data, record->data, record->size);
+ record->data = data;
+ needs_free = true;
+
+ /* detect leaf function and make it one-liner */
+ next = peek_ordered_record(ftrace);
+ if (next && next->cpu == record->cpu &&
+ pevent_data_type(event->pevent, next) == fgraph_exit_event->id) {
+ is_leaf = true;
+ /* consume record */
+ get_ordered_record(ftrace);
+ free(next);
+ }
+
+nested:
if (pevent_get_field_val(s, event, "depth", record, &depth, 1))
- return trace_seq_putc(s, '!');
+ goto out;

/* Function */
for (i = 0; i < (int)(depth * TRACE_GRAPH_INDENT); i++)
trace_seq_putc(s, ' ');

if (pevent_get_field_val(s, event, "func", record, &val, 1))
- return trace_seq_putc(s, '!');
+ goto out;

func = pevent_find_function(event->pevent, val);

if (func)
- trace_seq_printf(s, "%s() {", func);
+ trace_seq_printf(s, "%s()", func);
else
- trace_seq_printf(s, "%llx() {", val);
+ trace_seq_printf(s, "%llx()", val);

- trace_seq_putc(s, '\n');
- return 0;
+ if (is_leaf)
+ trace_seq_puts(s, ";\n");
+ else
+ trace_seq_puts(s, " {\n");
+
+ ret = 0;
+out:
+ if (needs_free)
+ free(record->data);
+
+ return ret;
}

static int
@@ -1069,7 +1112,8 @@ get_ftrace_event_record(struct perf_ftrace *ftrace,
return fra->record;
}

-static struct pevent_record *get_ordered_record(struct perf_ftrace *ftrace)
+static struct ftrace_report_arg *
+__get_ordered_record(struct perf_ftrace *ftrace)
{
struct ftrace_report_arg *fra = NULL;
struct ftrace_report_arg *tmp;
@@ -1097,9 +1141,26 @@ static struct pevent_record *get_ordered_record(struct perf_ftrace *ftrace)
fra = tmp;
}
}
+ return fra;
+}
+
+static struct pevent_record *peek_ordered_record(struct perf_ftrace *ftrace)
+{
+ struct ftrace_report_arg *fra = __get_ordered_record(ftrace);
+
+ if (fra)
+ return fra->record;
+
+ return NULL;
+}
+
+static struct pevent_record *get_ordered_record(struct perf_ftrace *ftrace)
+{
+ struct ftrace_report_arg *fra = __get_ordered_record(ftrace);

if (fra) {
- record = fra->record;
+ struct pevent_record *record = fra->record;
+
fra->record = NULL;
return record;
}
@@ -1153,10 +1214,10 @@ static int do_ftrace_show(struct perf_ftrace *ftrace)
function_handler, NULL);
pevent_register_event_handler(ftrace->pevent, -1,
"ftrace", "funcgraph_entry",
- fgraph_ent_handler, NULL);
+ fgraph_ent_handler, ftrace);
pevent_register_event_handler(ftrace->pevent, -1,
"ftrace", "funcgraph_exit",
- fgraph_ret_handler, NULL);
+ fgraph_ret_handler, ftrace);

if (perf_session__process_events(session, &show.tool) < 0) {
pr_err("failed to process events\n");
@@ -1164,6 +1225,10 @@ static int do_ftrace_show(struct perf_ftrace *ftrace)
goto out;
}

+ fgraph_exit_event = pevent_find_event_by_name(ftrace->pevent, "ftrace",
+ "funcgraph_exit");
+ BUG_ON(fgraph_exit_event == NULL);
+
trace_seq_init(&seq);

record = get_ordered_record(ftrace);
--
1.7.11.7

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