8 files changed, 108 insertions, 120 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index ac35cd214feb..e5fc14e53c05 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -715,28 +715,11 @@ union perf_event *perf_evlist__mmap_read_forward(struct perf_evlist *evlist, int
 	return perf_mmap__read_forward(md);
 }
 
-union perf_event *perf_evlist__mmap_read_backward(struct perf_evlist *evlist, int idx)
-{
-	struct perf_mmap *md = &evlist->mmap[idx];
-
-	/*
-	 * No need to check messup for backward ring buffer:
-	 * We can always read arbitrary long data from a backward
-	 * ring buffer unless we forget to pause it before reading.
-	 */
-	return perf_mmap__read_backward(md);
-}
-
 union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx)
 {
 	return perf_evlist__mmap_read_forward(evlist, idx);
 }
 
-void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx)
-{
-	perf_mmap__read_catchup(&evlist->mmap[idx]);
-}
-
 void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx)
 {
 	perf_mmap__consume(&evlist->mmap[idx], false);
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 75f8e0ad5d76..336b838e6957 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -133,10 +133,6 @@ union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx);
 
 union perf_event *perf_evlist__mmap_read_forward(struct perf_evlist *evlist,
 						 int idx);
-union perf_event *perf_evlist__mmap_read_backward(struct perf_evlist *evlist,
-						  int idx);
-void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx);
-
 void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx);
 
 int perf_evlist__open(struct perf_evlist *evlist);
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index ff359c9ece2e..ef351688b797 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -41,17 +41,7 @@
 
 #include "sane_ctype.h"
 
-static struct {
-	bool sample_id_all;
-	bool exclude_guest;
-	bool mmap2;
-	bool cloexec;
-	bool clockid;
-	bool clockid_wrong;
-	bool lbr_flags;
-	bool write_backward;
-	bool group_read;
-} perf_missing_features;
+struct perf_missing_features perf_missing_features;
 
 static clockid_t clockid;
 
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 846e41644525..a7487c6d1866 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -149,6 +149,20 @@ union u64_swap {
 	u32 val32[2];
 };
 
+struct perf_missing_features {
+	bool sample_id_all;
+	bool exclude_guest;
+	bool mmap2;
+	bool cloexec;
+	bool clockid;
+	bool clockid_wrong;
+	bool lbr_flags;
+	bool write_backward;
+	bool group_read;
+};
+
+extern struct perf_missing_features perf_missing_features;
+
 struct cpu_map;
 struct target;
 struct thread_map;
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index f6630cb95eff..02721b579746 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -430,7 +430,8 @@ int hist_entry__tui_annotate(struct hist_entry *he, struct perf_evsel *evsel,
 int perf_evlist__tui_browse_hists(struct perf_evlist *evlist, const char *help,
 				  struct hist_browser_timer *hbt,
 				  float min_pcnt,
-				  struct perf_env *env);
+				  struct perf_env *env,
+				  bool warn_lost_event);
 int script_browse(const char *script_opt);
 #else
 static inline
@@ -438,7 +439,8 @@ int perf_evlist__tui_browse_hists(struct perf_evlist *evlist __maybe_unused,
 				  const char *help __maybe_unused,
 				  struct hist_browser_timer *hbt __maybe_unused,
 				  float min_pcnt __maybe_unused,
-				  struct perf_env *env __maybe_unused)
+				  struct perf_env *env __maybe_unused,
+				  bool warn_lost_event __maybe_unused)
 {
 	return 0;
 }
diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 05076e683938..91531a7c8fbf 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -22,29 +22,27 @@ size_t perf_mmap__mmap_len(struct perf_mmap *map)
 
 /* When check_messup is true, 'end' must points to a good entry */
 static union perf_event *perf_mmap__read(struct perf_mmap *map,
-					 u64 start, u64 end, u64 *prev)
+					 u64 *startp, u64 end)
 {
 	unsigned char *data = map->base + page_size;
 	union perf_event *event = NULL;
-	int diff = end - start;
+	int diff = end - *startp;
 
 	if (diff >= (int)sizeof(event->header)) {
 		size_t size;
 
-		event = (union perf_event *)&data[start & map->mask];
+		event = (union perf_event *)&data[*startp & map->mask];
 		size = event->header.size;
 
-		if (size < sizeof(event->header) || diff < (int)size) {
-			event = NULL;
-			goto broken_event;
-		}
+		if (size < sizeof(event->header) || diff < (int)size)
+			return NULL;
 
 		/*
 		 * Event straddles the mmap boundary -- header should always
 		 * be inside due to u64 alignment of output.
 		 */
-		if ((start & map->mask) + size != ((start + size) & map->mask)) {
-			unsigned int offset = start;
+		if ((*startp & map->mask) + size != ((*startp + size) & map->mask)) {
+			unsigned int offset = *startp;
 			unsigned int len = min(sizeof(*event), size), cpy;
 			void *dst = map->event_copy;
 
@@ -59,20 +57,19 @@ static union perf_event *perf_mmap__read(struct perf_mmap *map,
 			event = (union perf_event *)map->event_copy;
 		}
 
-		start += size;
+		*startp += size;
 	}
 
-broken_event:
-	if (prev)
-		*prev = start;
-
 	return event;
 }
 
+/*
+ * legacy interface for mmap read.
+ * Don't use it. Use perf_mmap__read_event().
+ */
 union perf_event *perf_mmap__read_forward(struct perf_mmap *map)
 {
 	u64 head;
-	u64 old = map->prev;
 
 	/*
 	 * Check if event was unmapped due to a POLLHUP/POLLERR.
@@ -82,13 +79,26 @@ union perf_event *perf_mmap__read_forward(struct perf_mmap *map)
 
 	head = perf_mmap__read_head(map);
 
-	return perf_mmap__read(map, old, head, &map->prev);
+	return perf_mmap__read(map, &map->prev, head);
 }
 
-union perf_event *perf_mmap__read_backward(struct perf_mmap *map)
+/*
+ * Read event from ring buffer one by one.
+ * Return one event for each call.
+ *
+ * Usage:
+ * perf_mmap__read_init()
+ * while(event = perf_mmap__read_event()) {
+ *	//process the event
+ *	perf_mmap__consume()
+ * }
+ * perf_mmap__read_done()
+ */
+union perf_event *perf_mmap__read_event(struct perf_mmap *map,
+					bool overwrite,
+					u64 *startp, u64 end)
 {
-	u64 head, end;
-	u64 start = map->prev;
+	union perf_event *event;
 
 	/*
 	 * Check if event was unmapped due to a POLLHUP/POLLERR.
@@ -96,40 +106,19 @@ union perf_event *perf_mmap__read_backward(struct perf_mmap *map)
 	if (!refcount_read(&map->refcnt))
 		return NULL;
 
-	head = perf_mmap__read_head(map);
-	if (!head)
+	if (startp == NULL)
 		return NULL;
 
-	/*
-	 * 'head' pointer starts from 0. Kernel minus sizeof(record) form
-	 * it each time when kernel writes to it, so in fact 'head' is
-	 * negative. 'end' pointer is made manually by adding the size of
-	 * the ring buffer to 'head' pointer, means the validate data can
-	 * read is the whole ring buffer. If 'end' is positive, the ring
-	 * buffer has not fully filled, so we must adjust 'end' to 0.
-	 *
-	 * However, since both 'head' and 'end' is unsigned, we can't
-	 * simply compare 'end' against 0. Here we compare '-head' and
-	 * the size of the ring buffer, where -head is the number of bytes
-	 * kernel write to the ring buffer.
-	 */
-	if (-head < (u64)(map->mask + 1))
-		end = 0;
-	else
-		end = head + map->mask + 1;
-
-	return perf_mmap__read(map, start, end, &map->prev);
-}
+	/* non-overwirte doesn't pause the ringbuffer */
+	if (!overwrite)
+		end = perf_mmap__read_head(map);
 
-void perf_mmap__read_catchup(struct perf_mmap *map)
-{
-	u64 head;
+	event = perf_mmap__read(map, startp, end);
 
-	if (!refcount_read(&map->refcnt))
-		return;
+	if (!overwrite)
+		map->prev = *startp;
 
-	head = perf_mmap__read_head(map);
-	map->prev = head;
+	return event;
 }
 
 static bool perf_mmap__empty(struct perf_mmap *map)
@@ -267,41 +256,60 @@ static int overwrite_rb_find_range(void *buf, int mask, u64 head, u64 *start, u6
 	return -1;
 }
 
-int perf_mmap__push(struct perf_mmap *md, bool overwrite,
-		    void *to, int push(void *to, void *buf, size_t size))
+/*
+ * 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)
 {
 	u64 head = perf_mmap__read_head(md);
 	u64 old = md->prev;
-	u64 end = head, start = old;
 	unsigned char *data = md->base + page_size;
 	unsigned long size;
-	void *buf;
-	int rc = 0;
 
-	start = overwrite ? head : old;
-	end = overwrite ? old : head;
+	*startp = overwrite ? head : old;
+	*endp = overwrite ? old : head;
 
-	if (start == end)
-		return 0;
+	if (*startp == *endp)
+		return -EAGAIN;
 
-	size = end - start;
+	size = *endp - *startp;
 	if (size > (unsigned long)(md->mask) + 1) {
 		if (!overwrite) {
 			WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n");
 
 			md->prev = head;
 			perf_mmap__consume(md, overwrite);
-			return 0;
+			return -EAGAIN;
 		}
 
 		/*
 		 * Backward ring buffer is full. We still have a chance to read
 		 * most of data from it.
 		 */
-		if (overwrite_rb_find_range(data, md->mask, head, &start, &end))
-			return -1;
+		if (overwrite_rb_find_range(data, md->mask, head, startp, endp))
+			return -EINVAL;
 	}
 
+	return 0;
+}
+
+int perf_mmap__push(struct perf_mmap *md, bool overwrite,
+		    void *to, 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, overwrite, &start, &end);
+	if (rc < 0)
+		return (rc == -EAGAIN) ? 0 : -1;
+
+	size = end - start;
+
 	if ((start & md->mask) + size != (end & md->mask)) {
 		buf = &data[start & md->mask];
 		size = md->mask + 1 - (start & md->mask);
@@ -327,3 +335,14 @@ int perf_mmap__push(struct perf_mmap *md, bool overwrite,
 out:
 	return rc;
 }
+
+/*
+ * Mandatory for overwrite mode
+ * The direction of overwrite mode is backward.
+ * The last perf_mmap__read() will set tail to map->prev.
+ * Need to correct the map->prev to head which is the end of next read.
+ */
+void perf_mmap__read_done(struct perf_mmap *map)
+{
+	map->prev = perf_mmap__read_head(map);
+}
diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index e43d7b55a55f..ec7d3a24e276 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -65,8 +65,6 @@ void perf_mmap__put(struct perf_mmap *map);
 
 void perf_mmap__consume(struct perf_mmap *map, bool overwrite);
 
-void perf_mmap__read_catchup(struct perf_mmap *md);
-
 static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
 {
 	struct perf_event_mmap_page *pc = mm->base;
@@ -87,11 +85,17 @@ static inline void perf_mmap__write_tail(struct perf_mmap *md, u64 tail)
 }
 
 union perf_event *perf_mmap__read_forward(struct perf_mmap *map);
-union perf_event *perf_mmap__read_backward(struct perf_mmap *map);
+
+union perf_event *perf_mmap__read_event(struct perf_mmap *map,
+					bool overwrite,
+					u64 *startp, u64 end);
 
 int perf_mmap__push(struct perf_mmap *md, bool backward,
 		    void *to, int push(void *to, void *buf, size_t size));
 
 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);
+void perf_mmap__read_done(struct perf_mmap *map);
 #endif /*__PERF_MMAP_H */
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 443892dabedb..1019bbc5dbd8 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -340,35 +340,15 @@ size_t hex_width(u64 v)
 	return n;
 }
 
-static int hex(char ch)
-{
-	if ((ch >= '0') && (ch <= '9'))
-		return ch - '0';
-	if ((ch >= 'a') && (ch <= 'f'))
-		return ch - 'a' + 10;
-	if ((ch >= 'A') && (ch <= 'F'))
-		return ch - 'A' + 10;
-	return -1;
-}
-
 /*
  * While we find nice hex chars, build a long_val.
  * Return number of chars processed.
  */
 int hex2u64(const char *ptr, u64 *long_val)
 {
-	const char *p = ptr;
-	*long_val = 0;
-
-	while (*p) {
-		const int hex_val = hex(*p);
+	char *p;
 
-		if (hex_val < 0)
-			break;
-
-		*long_val = (*long_val << 4) | hex_val;
-		p++;
-	}
+	*long_val = strtoull(ptr, &p, 16);
 
 	return p - ptr;
 }