perf mmap: Simplify perf_mmap__read_init()

It isn't necessary to pass the 'start', 'end' and 'overwrite' arguments
to perf_mmap__read_init(). The data is stored in the struct perf_mmap.

Discard the parameters.

Signed-off-by: Kan Liang <[e-mail]>
Suggested-by: Arnaldo Carvalho de Melo <[e-mail]>
Acked-by: Jiri Olsa <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Wang Nan <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/arch/x86/tests/perf-time-to-tsc.c

···
 	u64 test_tsc, comm1_tsc, comm2_tsc;
 	u64 test_time, comm1_time = 0, comm2_time = 0;
 	struct perf_mmap *md;
-	u64 end, start;
 
 	threads = thread_map__new(-1, getpid(), UINT_MAX);
 	CHECK_NOT_NULL__(threads);
···
 
 	for (i = 0; i < evlist->nr_mmaps; i++) {
 		md = &evlist->mmap[i];
-		if (perf_mmap__read_init(md, false, &start, &end) < 0)
+		if (perf_mmap__read_init(md) < 0)
 			continue;
 
 		while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/builtin-kvm.c

···
 	struct perf_evlist *evlist = kvm->evlist;
 	union perf_event *event;
 	struct perf_mmap *md;
-	u64 end, start;
 	u64 timestamp;
 	s64 n = 0;
 	int err;
 
 	*mmap_time = ULLONG_MAX;
 	md = &evlist->mmap[idx];
-	err = perf_mmap__read_init(md, false, &start, &end);
+	err = perf_mmap__read_init(md);
 	if (err < 0)
 		return (err == -EAGAIN) ? 0 : -1;
 

tools/perf/builtin-top.c

···
 	struct perf_session *session = top->session;
 	union perf_event *event;
 	struct machine *machine;
-	u64 end, start;
 	int ret;
 
 	md = opts->overwrite ? &evlist->overwrite_mmap[idx] : &evlist->mmap[idx];
-	if (perf_mmap__read_init(md, opts->overwrite, &start, &end) < 0)
+	if (perf_mmap__read_init(md) < 0)
 		return;
 
 	while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/builtin-trace.c

···
 	for (i = 0; i < evlist->nr_mmaps; i++) {
 		union perf_event *event;
 		struct perf_mmap *md;
-		u64 end, start;
 
 		md = &evlist->mmap[i];
-		if (perf_mmap__read_init(md, false, &start, &end) < 0)
+		if (perf_mmap__read_init(md) < 0)
 			continue;
 
 		while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/tests/backward-ring-buffer.c

···
 	for (i = 0; i < evlist->nr_mmaps; i++) {
 		struct perf_mmap *map = &evlist->overwrite_mmap[i];
 		union perf_event *event;
-		u64 start, end;
 
-		perf_mmap__read_init(map, true, &start, &end);
+		perf_mmap__read_init(map);
 		while ((event = perf_mmap__read_event(map)) != NULL) {
 			const u32 type = event->header.type;
 

tools/perf/tests/bpf.c

···
 	for (i = 0; i < evlist->nr_mmaps; i++) {
 		union perf_event *event;
 		struct perf_mmap *md;
-		u64 end, start;
 
 		md = &evlist->mmap[i];
-		if (perf_mmap__read_init(md, false, &start, &end) < 0)
+		if (perf_mmap__read_init(md) < 0)
 			continue;
 
 		while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/tests/code-reading.c

···
 {
 	union perf_event *event;
 	struct perf_mmap *md;
-	u64 end, start;
 	int i, ret;
 
 	for (i = 0; i < evlist->nr_mmaps; i++) {
 		md = &evlist->mmap[i];
-		if (perf_mmap__read_init(md, false, &start, &end) < 0)
+		if (perf_mmap__read_init(md) < 0)
 			continue;
 
 		while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/tests/keep-tracking.c

···
 {
 	union perf_event *event;
 	struct perf_mmap *md;
-	u64 end, start;
 	int i, found;
 
 	found = 0;
 	for (i = 0; i < evlist->nr_mmaps; i++) {
 		md = &evlist->mmap[i];
-		if (perf_mmap__read_init(md, false, &start, &end) < 0)
+		if (perf_mmap__read_init(md) < 0)
 			continue;
 		while ((event = perf_mmap__read_event(md)) != NULL) {
 			if (event->header.type == PERF_RECORD_COMM &&

tools/perf/tests/mmap-basic.c

···
 	struct perf_evsel *evsels[nsyscalls], *evsel;
 	char sbuf[STRERR_BUFSIZE];
 	struct perf_mmap *md;
-	u64 end, start;
 
 	threads = thread_map__new(-1, getpid(), UINT_MAX);
 	if (threads == NULL) {
···
 		}
 
 	md = &evlist->mmap[0];
-	if (perf_mmap__read_init(md, false, &start, &end) < 0)
+	if (perf_mmap__read_init(md) < 0)
 		goto out_init;
 
 	while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/tests/openat-syscall-tp-fields.c

···
 		for (i = 0; i < evlist->nr_mmaps; i++) {
 			union perf_event *event;
 			struct perf_mmap *md;
-			u64 end, start;
 
 			md = &evlist->mmap[i];
-			if (perf_mmap__read_init(md, false, &start, &end) < 0)
+			if (perf_mmap__read_init(md) < 0)
 				continue;
 
 			while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/tests/perf-record.c

···
 		for (i = 0; i < evlist->nr_mmaps; i++) {
 			union perf_event *event;
 			struct perf_mmap *md;
-			u64 end, start;
 
 			md = &evlist->mmap[i];
-			if (perf_mmap__read_init(md, false, &start, &end) < 0)
+			if (perf_mmap__read_init(md) < 0)
 				continue;
 
 			while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/tests/sw-clock.c

···
 	struct cpu_map *cpus;
 	struct thread_map *threads;
 	struct perf_mmap *md;
-	u64 end, start;
 
 	attr.sample_freq = 500;
 
···
 	perf_evlist__disable(evlist);
 
 	md = &evlist->mmap[0];
-	if (perf_mmap__read_init(md, false, &start, &end) < 0)
+	if (perf_mmap__read_init(md) < 0)
 		goto out_init;
 
 	while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/tests/switch-tracking.c

···
 	LIST_HEAD(events);
 	struct event_node *events_array, *node;
 	struct perf_mmap *md;
-	u64 end, start;
 	int i, ret;
 
 	for (i = 0; i < evlist->nr_mmaps; i++) {
 		md = &evlist->mmap[i];
-		if (perf_mmap__read_init(md, false, &start, &end) < 0)
+		if (perf_mmap__read_init(md) < 0)
 			continue;
 
 		while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/tests/task-exit.c

···
 	struct cpu_map *cpus;
 	struct thread_map *threads;
 	struct perf_mmap *md;
-	u64 end, start;
 
 	signal(SIGCHLD, sig_handler);
 
···
 
 retry:
 	md = &evlist->mmap[0];
-	if (perf_mmap__read_init(md, false, &start, &end) < 0)
+	if (perf_mmap__read_init(md) < 0)
 		goto out_init;
 
 	while ((event = perf_mmap__read_event(md)) != NULL) {

tools/perf/util/mmap.c

···
 /*
  * Report the start and end of the available data in ringbuffer
  */
-int perf_mmap__read_init(struct perf_mmap *md, bool overwrite,
-			 u64 *startp, u64 *endp)
+int perf_mmap__read_init(struct perf_mmap *md)
 {
 	u64 head = perf_mmap__read_head(md);
 	u64 old = md->prev;
 	unsigned char *data = md->base + page_size;
 	unsigned long size;
 
-	*startp = overwrite ? head : old;
-	*endp = overwrite ? old : head;
 	md->start = md->overwrite ? head : old;
 	md->end = md->overwrite ? old : head;
 
···
 		 */
 		if (overwrite_rb_find_range(data, md->mask, head, &md->start, &md->end))
 			return -EINVAL;
-		*startp = md->start;
-		*endp = md->end;
 	}
 
 	return 0;
···
 		    int push(void *to, void *buf, size_t size))
 {
 	u64 head = perf_mmap__read_head(md);
-	u64 end, start;
 	unsigned char *data = md->base + page_size;
 	unsigned long size;
 	void *buf;
 	int rc = 0;
 
-	rc = perf_mmap__read_init(md, md->overwrite, &start, &end);
+	rc = perf_mmap__read_init(md);
 	if (rc < 0)
 		return (rc == -EAGAIN) ? 0 : -1;
 

tools/perf/util/mmap.h

···
 
 size_t perf_mmap__mmap_len(struct perf_mmap *map);
 
-int perf_mmap__read_init(struct perf_mmap *md, bool overwrite,
-			 u64 *startp, u64 *endp);
+int perf_mmap__read_init(struct perf_mmap *md);
 void perf_mmap__read_done(struct perf_mmap *map);
 #endif /*__PERF_MMAP_H */

tools/perf/util/python.c

···
 	int sample_id_all = 1, cpu;
 	static char *kwlist[] = { "cpu", "sample_id_all", NULL };
 	struct perf_mmap *md;
-	u64 end, start;
 	int err;
 
 	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "i|i", kwlist,
···
 		return NULL;
 
 	md = &evlist->mmap[cpu];
-	if (perf_mmap__read_init(md, false, &start, &end) < 0)
+	if (perf_mmap__read_init(md) < 0)
 		goto end;
 
 	event = perf_mmap__read_event(md);