perf tools: Add 'trace' sort key

The 'trace' sort key is to show tracepoint event output using either
print fmt or plugin.  For example sched_switch event (using plugin) will
show output like below:

  # perf record -e sched:sched_switch -a usleep 10
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.197 MB perf.data (69 samples) ]
  #

  $ perf report -s trace --stdio
  ...
  # Overhead  Trace output
  # ........  ...................................................
  #
       9.48%  swapper/0:0 [120] R ==> transmission-gt:17773 [120]
       9.48%  transmission-gt:17773 [120] S ==> swapper/0:0 [120]
       9.04%  swapper/2:0 [120] R ==> transmission-gt:17773 [120]
       8.92%  transmission-gt:17773 [120] S ==> swapper/2:0 [120]
       5.25%  swapper/0:0 [120] R ==> kworker/0:1H:109 [100]
       5.21%  kworker/0:1H:109 [100] S ==> swapper/0:0 [120]
       1.78%  swapper/3:0 [120] R ==> transmission-gt:17773 [120]
       1.78%  transmission-gt:17773 [120] S ==> swapper/3:0 [120]
       1.53%  Xephyr:6524 [120] S ==> swapper/0:0 [120]
       1.53%  swapper/0:0 [120] R ==> Xephyr:6524 [120]
       1.17%  swapper/2:0 [120] R ==> irq/33-iwlwifi:233 [49]
       1.13%  irq/33-iwlwifi:233 [49] S ==> swapper/2:0 [120]

Note that the 'trace' sort key works only for tracepoint events.  If
it's used to other type of events, just "N/A" will be printed.

Suggested-and-acked-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1450804030-29193-8-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/hist.h

@@ -52,6 +52,7 @@ enum hist_column {
 	HISTC_MEM_IADDR_SYMBOL,
 	HISTC_TRANSACTION,
 	HISTC_CYCLES,
+	HISTC_TRACE,
 	HISTC_NR_COLS, /* Last entry */
 };
 

tools/perf/util/sort.c

@@ -445,6 +445,65 @@ struct sort_entry sort_socket = {
 	.se_width_idx	= HISTC_SOCKET,
 };
 
+/* --sort trace */
+
+static char *get_trace_output(struct hist_entry *he)
+{
+	struct trace_seq seq;
+	struct perf_evsel *evsel;
+	struct pevent_record rec = {
+		.data = he->raw_data,
+		.size = he->raw_size,
+	};
+
+	evsel = hists_to_evsel(he->hists);
+
+	trace_seq_init(&seq);
+	pevent_event_info(&seq, evsel->tp_format, &rec);
+	return seq.buffer;
+}
+
+static int64_t
+sort__trace_cmp(struct hist_entry *left, struct hist_entry *right)
+{
+	struct perf_evsel *evsel;
+
+	evsel = hists_to_evsel(left->hists);
+	if (evsel->attr.type != PERF_TYPE_TRACEPOINT)
+		return 0;
+
+	if (left->trace_output == NULL)
+		left->trace_output = get_trace_output(left);
+	if (right->trace_output == NULL)
+		right->trace_output = get_trace_output(right);
+
+	hists__new_col_len(left->hists, HISTC_TRACE, strlen(left->trace_output));
+	hists__new_col_len(right->hists, HISTC_TRACE, strlen(right->trace_output));
+
+	return strcmp(right->trace_output, left->trace_output);
+}
+
+static int hist_entry__trace_snprintf(struct hist_entry *he, char *bf,
+				    size_t size, unsigned int width)
+{
+	struct perf_evsel *evsel;
+
+	evsel = hists_to_evsel(he->hists);
+	if (evsel->attr.type != PERF_TYPE_TRACEPOINT)
+		return scnprintf(bf, size, "%-*.*s", width, width, "N/A");
+
+	if (he->trace_output == NULL)
+		he->trace_output = get_trace_output(he);
+	return repsep_snprintf(bf, size, "%-*.*s", width, width, he->trace_output);
+}
+
+struct sort_entry sort_trace = {
+	.se_header      = "Trace output",
+	.se_cmp	        = sort__trace_cmp,
+	.se_snprintf    = hist_entry__trace_snprintf,
+	.se_width_idx	= HISTC_TRACE,
+};
+
 /* sort keys for branch stacks */
 
 static int64_t
@@ -1314,6 +1373,7 @@ static struct sort_dimension common_sort_dimensions[] = {
 	DIM(SORT_LOCAL_WEIGHT, "local_weight", sort_local_weight),
 	DIM(SORT_GLOBAL_WEIGHT, "weight", sort_global_weight),
 	DIM(SORT_TRANSACTION, "transaction", sort_transaction),
+	DIM(SORT_TRACE, "trace", sort_trace),
 };
 
 #undef DIM
@@ -1560,22 +1620,6 @@ static int hde_width(struct hpp_dynamic_entry *hde)
 	return hde->hpp.len;
 }
 
-static char *get_trace_output(struct hist_entry *he)
-{
-	struct trace_seq seq;
-	struct perf_evsel *evsel;
-	struct pevent_record rec = {
-		.data = he->raw_data,
-		.size = he->raw_size,
-	};
-
-	evsel = hists_to_evsel(he->hists);
-
-	trace_seq_init(&seq);
-	pevent_event_info(&seq, evsel->tp_format, &rec);
-	return seq.buffer;
-}
-
 static void update_dynamic_len(struct hpp_dynamic_entry *hde,
 			       struct hist_entry *he)
 {

tools/perf/util/sort.h

@@ -183,6 +183,7 @@ enum sort_type {
 	SORT_LOCAL_WEIGHT,
 	SORT_GLOBAL_WEIGHT,
 	SORT_TRANSACTION,
+	SORT_TRACE,
 
 	/* branch stack specific sort keys */
 	__SORT_BRANCH_STACK,