perf tools: Implement branch_type event parameter

It can be useful to specify branch type state per event, for example if
we want to collect both software trace points and last branch PMU events
in a single collection. Currently this doesn't work because the software
trace point errors out with -b.

There was already a branch-type parameter to configure branch sample
types per event in the parser, but it was stubbed out. This patch
implements the necessary plumbing to actually enable it.

Now:

  $ perf record -e sched:sched_switch,cpu/cpu-cycles,branch_type=any/ ...

works.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1476306127-19721-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evsel.c

@@ -28,6 +28,7 @@
 #include "debug.h"
 #include "trace-event.h"
 #include "stat.h"
+#include "util/parse-branch-options.h"
 
 static struct {
 	bool sample_id_all;
@@ -708,6 +709,14 @@ static void apply_config_terms(struct perf_evsel *evsel,
 		case PERF_EVSEL__CONFIG_TERM_CALLGRAPH:
 			callgraph_buf = term->val.callgraph;
 			break;
+		case PERF_EVSEL__CONFIG_TERM_BRANCH:
+			if (term->val.branch && strcmp(term->val.branch, "no")) {
+				perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
+				parse_branch_str(term->val.branch,
+						 &attr->branch_sample_type);
+			} else
+				perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
+			break;
 		case PERF_EVSEL__CONFIG_TERM_STACK_USER:
 			dump_size = term->val.stack_user;
 			break;

tools/perf/util/evsel.h

@@ -47,6 +47,7 @@ enum {
 	PERF_EVSEL__CONFIG_TERM_MAX_STACK,
 	PERF_EVSEL__CONFIG_TERM_OVERWRITE,
 	PERF_EVSEL__CONFIG_TERM_DRV_CFG,
+	PERF_EVSEL__CONFIG_TERM_BRANCH,
 	PERF_EVSEL__CONFIG_TERM_MAX,
 };
 
@@ -63,6 +64,7 @@ struct perf_evsel_config_term {
 		int	max_stack;
 		bool	inherit;
 		bool	overwrite;
+		char	*branch;
 	} val;
 };
 

tools/perf/util/parse-branch-options.c

@@ -31,18 +31,65 @@ static const struct branch_mode branch_modes[] = {
 	BRANCH_END
 };
 
-int
-parse_branch_stack(const struct option *opt, const char *str, int unset)
+int parse_branch_str(const char *str, __u64 *mode)
 {
 #define ONLY_PLM \
 	(PERF_SAMPLE_BRANCH_USER	|\
 	 PERF_SAMPLE_BRANCH_KERNEL	|\
 	 PERF_SAMPLE_BRANCH_HV)
 
-	uint64_t *mode = (uint64_t *)opt->value;
+	int ret = 0;
+	char *p, *s;
+	char *os = NULL;
 	const struct branch_mode *br;
-	char *s, *os = NULL, *p;
-	int ret = -1;
+
+	if (str == NULL) {
+		*mode = PERF_SAMPLE_BRANCH_ANY;
+		return 0;
+	}
+
+	/* because str is read-only */
+	s = os = strdup(str);
+	if (!s)
+		return -1;
+
+	for (;;) {
+		p = strchr(s, ',');
+		if (p)
+			*p = '\0';
+
+		for (br = branch_modes; br->name; br++) {
+			if (!strcasecmp(s, br->name))
+				break;
+		}
+		if (!br->name) {
+			ret = -1;
+			ui__warning("unknown branch filter %s,"
+				    " check man page\n", s);
+			goto error;
+		}
+
+		*mode |= br->mode;
+
+		if (!p)
+			break;
+
+		s = p + 1;
+	}
+
+	/* default to any branch */
+	if ((*mode & ~ONLY_PLM) == 0) {
+		*mode = PERF_SAMPLE_BRANCH_ANY;
+	}
+error:
+	free(os);
+	return ret;
+}
+
+int
+parse_branch_stack(const struct option *opt, const char *str, int unset)
+{
+	__u64 *mode = (__u64 *)opt->value;
 
 	if (unset)
 		return 0;
@@ -53,43 +100,5 @@ parse_branch_stack(const struct option *opt, const char *str, int unset)
 	if (*mode)
 		return -1;
 
-	/* str may be NULL in case no arg is passed to -b */
-	if (str) {
-		/* because str is read-only */
-		s = os = strdup(str);
-		if (!s)
-			return -1;
-
-		for (;;) {
-			p = strchr(s, ',');
-			if (p)
-				*p = '\0';
-
-			for (br = branch_modes; br->name; br++) {
-				if (!strcasecmp(s, br->name))
-					break;
-			}
-			if (!br->name) {
-				ui__warning("unknown branch filter %s,"
-					    " check man page\n", s);
-				goto error;
-			}
-
-			*mode |= br->mode;
-
-			if (!p)
-				break;
-
-			s = p + 1;
-		}
-	}
-	ret = 0;
-
-	/* default to any branch */
-	if ((*mode & ~ONLY_PLM) == 0) {
-		*mode = PERF_SAMPLE_BRANCH_ANY;
-	}
-error:
-	free(os);
-	return ret;
+	return parse_branch_str(str, mode);
 }

tools/perf/util/parse-branch-options.h

@@ -1,5 +1,6 @@
 #ifndef _PERF_PARSE_BRANCH_OPTIONS_H
 #define _PERF_PARSE_BRANCH_OPTIONS_H 1
-struct option;
+#include <stdint.h>
 int parse_branch_stack(const struct option *opt, const char *str, int unset);
+int parse_branch_str(const char *str, __u64 *mode);
 #endif /* _PERF_PARSE_BRANCH_OPTIONS_H */

tools/perf/util/parse-events.c

@@ -22,6 +22,7 @@
 #include "cpumap.h"
 #include "probe-file.h"
 #include "asm/bug.h"
+#include "util/parse-branch-options.h"
 
 #define MAX_NAME_LEN 100
 
@@ -973,10 +974,13 @@ do {									   \
 		CHECK_TYPE_VAL(NUM);
 		break;
 	case PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE:
-		/*
-		 * TODO uncomment when the field is available
-		 * attr->branch_sample_type = term->val.num;
-		 */
+		CHECK_TYPE_VAL(STR);
+		if (strcmp(term->val.str, "no") &&
+		    parse_branch_str(term->val.str, &attr->branch_sample_type)) {
+			err->str = strdup("invalid branch sample type");
+			err->idx = term->err_val;
+			return -EINVAL;
+		}
 		break;
 	case PARSE_EVENTS__TERM_TYPE_TIME:
 		CHECK_TYPE_VAL(NUM);
@@ -1119,6 +1123,9 @@ do {								\
 		case PARSE_EVENTS__TERM_TYPE_CALLGRAPH:
 			ADD_CONFIG_TERM(CALLGRAPH, callgraph, term->val.str);
 			break;
+		case PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE:
+			ADD_CONFIG_TERM(BRANCH, branch, term->val.str);
+			break;
 		case PARSE_EVENTS__TERM_TYPE_STACKSIZE:
 			ADD_CONFIG_TERM(STACK_USER, stack_user, term->val.num);
 			break;