perf tools: Move UI bits to tools/perf/ui directory

Move those files to new directory in order to be prepared to further UI
work. Makefile and header file pathes are adjusted accordingly.

Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Suggested-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl
Link: http://lkml.kernel.org/r/1333523666-12057-1-git-send-email-namhyung.kim@lge.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1345 insertions, 0 deletions

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
new file mode 100644
index 000000000000..466827e91b87
--- /dev/null
+++ b/tools/perf/ui/browsers/hists.c
@@ -0,0 +1,1345 @@
+#include <stdio.h>
+#include "../libslang.h"
+#include <stdlib.h>
+#include <string.h>
+#include <newt.h>
+#include <linux/rbtree.h>
+
+#include "../../util/evsel.h"
+#include "../../util/evlist.h"
+#include "../../util/hist.h"
+#include "../../util/pstack.h"
+#include "../../util/sort.h"
+#include "../../util/util.h"
+
+#include "../browser.h"
+#include "../helpline.h"
+#include "../util.h"
+#include "../ui.h"
+#include "map.h"
+
+struct hist_browser {
+	struct ui_browser   b;
+	struct hists	    *hists;
+	struct hist_entry   *he_selection;
+	struct map_symbol   *selection;
+	bool		     has_symbols;
+};
+
+static int hists__browser_title(struct hists *self, char *bf, size_t size,
+				const char *ev_name);
+
+static void hist_browser__refresh_dimensions(struct hist_browser *self)
+{
+	/* 3 == +/- toggle symbol before actual hist_entry rendering */
+	self->b.width = 3 + (hists__sort_list_width(self->hists) +
+			     sizeof("[k]"));
+}
+
+static void hist_browser__reset(struct hist_browser *self)
+{
+	self->b.nr_entries = self->hists->nr_entries;
+	hist_browser__refresh_dimensions(self);
+	ui_browser__reset_index(&self->b);
+}
+
+static char tree__folded_sign(bool unfolded)
+{
+	return unfolded ? '-' : '+';
+}
+
+static char map_symbol__folded(const struct map_symbol *self)
+{
+	return self->has_children ? tree__folded_sign(self->unfolded) : ' ';
+}
+
+static char hist_entry__folded(const struct hist_entry *self)
+{
+	return map_symbol__folded(&self->ms);
+}
+
+static char callchain_list__folded(const struct callchain_list *self)
+{
+	return map_symbol__folded(&self->ms);
+}
+
+static void map_symbol__set_folding(struct map_symbol *self, bool unfold)
+{
+	self->unfolded = unfold ? self->has_children : false;
+}
+
+static int callchain_node__count_rows_rb_tree(struct callchain_node *self)
+{
+	int n = 0;
+	struct rb_node *nd;
+
+	for (nd = rb_first(&self->rb_root); nd; nd = rb_next(nd)) {
+		struct callchain_node *child = rb_entry(nd, struct callchain_node, rb_node);
+		struct callchain_list *chain;
+		char folded_sign = ' '; /* No children */
+
+		list_for_each_entry(chain, &child->val, list) {
+			++n;
+			/* We need this because we may not have children */
+			folded_sign = callchain_list__folded(chain);
+			if (folded_sign == '+')
+				break;
+		}
+
+		if (folded_sign == '-') /* Have children and they're unfolded */
+			n += callchain_node__count_rows_rb_tree(child);
+	}
+
+	return n;
+}
+
+static int callchain_node__count_rows(struct callchain_node *node)
+{
+	struct callchain_list *chain;
+	bool unfolded = false;
+	int n = 0;
+
+	list_for_each_entry(chain, &node->val, list) {
+		++n;
+		unfolded = chain->ms.unfolded;
+	}
+
+	if (unfolded)
+		n += callchain_node__count_rows_rb_tree(node);
+
+	return n;
+}
+
+static int callchain__count_rows(struct rb_root *chain)
+{
+	struct rb_node *nd;
+	int n = 0;
+
+	for (nd = rb_first(chain); nd; nd = rb_next(nd)) {
+		struct callchain_node *node = rb_entry(nd, struct callchain_node, rb_node);
+		n += callchain_node__count_rows(node);
+	}
+
+	return n;
+}
+
+static bool map_symbol__toggle_fold(struct map_symbol *self)
+{
+	if (!self)
+		return false;
+
+	if (!self->has_children)
+		return false;
+
+	self->unfolded = !self->unfolded;
+	return true;
+}
+
+static void callchain_node__init_have_children_rb_tree(struct callchain_node *self)
+{
+	struct rb_node *nd = rb_first(&self->rb_root);
+
+	for (nd = rb_first(&self->rb_root); nd; nd = rb_next(nd)) {
+		struct callchain_node *child = rb_entry(nd, struct callchain_node, rb_node);
+		struct callchain_list *chain;
+		bool first = true;
+
+		list_for_each_entry(chain, &child->val, list) {
+			if (first) {
+				first = false;
+				chain->ms.has_children = chain->list.next != &child->val ||
+							 !RB_EMPTY_ROOT(&child->rb_root);
+			} else
+				chain->ms.has_children = chain->list.next == &child->val &&
+							 !RB_EMPTY_ROOT(&child->rb_root);
+		}
+
+		callchain_node__init_have_children_rb_tree(child);
+	}
+}
+
+static void callchain_node__init_have_children(struct callchain_node *self)
+{
+	struct callchain_list *chain;
+
+	list_for_each_entry(chain, &self->val, list)
+		chain->ms.has_children = !RB_EMPTY_ROOT(&self->rb_root);
+
+	callchain_node__init_have_children_rb_tree(self);
+}
+
+static void callchain__init_have_children(struct rb_root *self)
+{
+	struct rb_node *nd;
+
+	for (nd = rb_first(self); nd; nd = rb_next(nd)) {
+		struct callchain_node *node = rb_entry(nd, struct callchain_node, rb_node);
+		callchain_node__init_have_children(node);
+	}
+}
+
+static void hist_entry__init_have_children(struct hist_entry *self)
+{
+	if (!self->init_have_children) {
+		self->ms.has_children = !RB_EMPTY_ROOT(&self->sorted_chain);
+		callchain__init_have_children(&self->sorted_chain);
+		self->init_have_children = true;
+	}
+}
+
+static bool hist_browser__toggle_fold(struct hist_browser *self)
+{
+	if (map_symbol__toggle_fold(self->selection)) {
+		struct hist_entry *he = self->he_selection;
+
+		hist_entry__init_have_children(he);
+		self->hists->nr_entries -= he->nr_rows;
+
+		if (he->ms.unfolded)
+			he->nr_rows = callchain__count_rows(&he->sorted_chain);
+		else
+			he->nr_rows = 0;
+		self->hists->nr_entries += he->nr_rows;
+		self->b.nr_entries = self->hists->nr_entries;
+
+		return true;
+	}
+
+	/* If it doesn't have children, no toggling performed */
+	return false;
+}
+
+static int callchain_node__set_folding_rb_tree(struct callchain_node *self, bool unfold)
+{
+	int n = 0;
+	struct rb_node *nd;
+
+	for (nd = rb_first(&self->rb_root); nd; nd = rb_next(nd)) {
+		struct callchain_node *child = rb_entry(nd, struct callchain_node, rb_node);
+		struct callchain_list *chain;
+		bool has_children = false;
+
+		list_for_each_entry(chain, &child->val, list) {
+			++n;
+			map_symbol__set_folding(&chain->ms, unfold);
+			has_children = chain->ms.has_children;
+		}
+
+		if (has_children)
+			n += callchain_node__set_folding_rb_tree(child, unfold);
+	}
+
+	return n;
+}
+
+static int callchain_node__set_folding(struct callchain_node *node, bool unfold)
+{
+	struct callchain_list *chain;
+	bool has_children = false;
+	int n = 0;
+
+	list_for_each_entry(chain, &node->val, list) {
+		++n;
+		map_symbol__set_folding(&chain->ms, unfold);
+		has_children = chain->ms.has_children;
+	}
+
+	if (has_children)
+		n += callchain_node__set_folding_rb_tree(node, unfold);
+
+	return n;
+}
+
+static int callchain__set_folding(struct rb_root *chain, bool unfold)
+{
+	struct rb_node *nd;
+	int n = 0;
+
+	for (nd = rb_first(chain); nd; nd = rb_next(nd)) {
+		struct callchain_node *node = rb_entry(nd, struct callchain_node, rb_node);
+		n += callchain_node__set_folding(node, unfold);
+	}
+
+	return n;
+}
+
+static void hist_entry__set_folding(struct hist_entry *self, bool unfold)
+{
+	hist_entry__init_have_children(self);
+	map_symbol__set_folding(&self->ms, unfold);
+
+	if (self->ms.has_children) {
+		int n = callchain__set_folding(&self->sorted_chain, unfold);
+		self->nr_rows = unfold ? n : 0;
+	} else
+		self->nr_rows = 0;
+}
+
+static void hists__set_folding(struct hists *self, bool unfold)
+{
+	struct rb_node *nd;
+
+	self->nr_entries = 0;
+
+	for (nd = rb_first(&self->entries); nd; nd = rb_next(nd)) {
+		struct hist_entry *he = rb_entry(nd, struct hist_entry, rb_node);
+		hist_entry__set_folding(he, unfold);
+		self->nr_entries += 1 + he->nr_rows;
+	}
+}
+
+static void hist_browser__set_folding(struct hist_browser *self, bool unfold)
+{
+	hists__set_folding(self->hists, unfold);
+	self->b.nr_entries = self->hists->nr_entries;
+	/* Go to the start, we may be way after valid entries after a collapse */
+	ui_browser__reset_index(&self->b);
+}
+
+static void ui_browser__warn_lost_events(struct ui_browser *browser)
+{
+	ui_browser__warning(browser, 4,
+		"Events are being lost, check IO/CPU overload!\n\n"
+		"You may want to run 'perf' using a RT scheduler policy:\n\n"
+		" perf top -r 80\n\n"
+		"Or reduce the sampling frequency.");
+}
+
+static int hist_browser__run(struct hist_browser *self, const char *ev_name,
+			     void(*timer)(void *arg), void *arg, int delay_secs)
+{
+	int key;
+	char title[160];
+
+	self->b.entries = &self->hists->entries;
+	self->b.nr_entries = self->hists->nr_entries;
+
+	hist_browser__refresh_dimensions(self);
+	hists__browser_title(self->hists, title, sizeof(title), ev_name);
+
+	if (ui_browser__show(&self->b, title,
+			     "Press '?' for help on key bindings") < 0)
+		return -1;
+
+	while (1) {
+		key = ui_browser__run(&self->b, delay_secs);
+
+		switch (key) {
+		case K_TIMER:
+			timer(arg);
+			ui_browser__update_nr_entries(&self->b, self->hists->nr_entries);
+
+			if (self->hists->stats.nr_lost_warned !=
+			    self->hists->stats.nr_events[PERF_RECORD_LOST]) {
+				self->hists->stats.nr_lost_warned =
+					self->hists->stats.nr_events[PERF_RECORD_LOST];
+				ui_browser__warn_lost_events(&self->b);
+			}
+
+			hists__browser_title(self->hists, title, sizeof(title), ev_name);
+			ui_browser__show_title(&self->b, title);
+			continue;
+		case 'D': { /* Debug */
+			static int seq;
+			struct hist_entry *h = rb_entry(self->b.top,
+							struct hist_entry, rb_node);
+			ui_helpline__pop();
+			ui_helpline__fpush("%d: nr_ent=(%d,%d), height=%d, idx=%d, fve: idx=%d, row_off=%d, nrows=%d",
+					   seq++, self->b.nr_entries,
+					   self->hists->nr_entries,
+					   self->b.height,
+					   self->b.index,
+					   self->b.top_idx,
+					   h->row_offset, h->nr_rows);
+		}
+			break;
+		case 'C':
+			/* Collapse the whole world. */
+			hist_browser__set_folding(self, false);
+			break;
+		case 'E':
+			/* Expand the whole world. */
+			hist_browser__set_folding(self, true);
+			break;
+		case K_ENTER:
+			if (hist_browser__toggle_fold(self))
+				break;
+			/* fall thru */
+		default:
+			goto out;
+		}
+	}
+out:
+	ui_browser__hide(&self->b);
+	return key;
+}
+
+static char *callchain_list__sym_name(struct callchain_list *self,
+				      char *bf, size_t bfsize)
+{
+	if (self->ms.sym)
+		return self->ms.sym->name;
+
+	snprintf(bf, bfsize, "%#" PRIx64, self->ip);
+	return bf;
+}
+
+#define LEVEL_OFFSET_STEP 3
+
+static int hist_browser__show_callchain_node_rb_tree(struct hist_browser *self,
+						     struct callchain_node *chain_node,
+						     u64 total, int level,
+						     unsigned short row,
+						     off_t *row_offset,
+						     bool *is_current_entry)
+{
+	struct rb_node *node;
+	int first_row = row, width, offset = level * LEVEL_OFFSET_STEP;
+	u64 new_total, remaining;
+
+	if (callchain_param.mode == CHAIN_GRAPH_REL)
+		new_total = chain_node->children_hit;
+	else
+		new_total = total;
+
+	remaining = new_total;
+	node = rb_first(&chain_node->rb_root);
+	while (node) {
+		struct callchain_node *child = rb_entry(node, struct callchain_node, rb_node);
+		struct rb_node *next = rb_next(node);
+		u64 cumul = callchain_cumul_hits(child);
+		struct callchain_list *chain;
+		char folded_sign = ' ';
+		int first = true;
+		int extra_offset = 0;
+
+		remaining -= cumul;
+
+		list_for_each_entry(chain, &child->val, list) {
+			char ipstr[BITS_PER_LONG / 4 + 1], *alloc_str;
+			const char *str;
+			int color;
+			bool was_first = first;
+
+			if (first)
+				first = false;
+			else
+				extra_offset = LEVEL_OFFSET_STEP;
+
+			folded_sign = callchain_list__folded(chain);
+			if (*row_offset != 0) {
+				--*row_offset;
+				goto do_next;
+			}
+
+			alloc_str = NULL;
+			str = callchain_list__sym_name(chain, ipstr, sizeof(ipstr));
+			if (was_first) {
+				double percent = cumul * 100.0 / new_total;
+
+				if (asprintf(&alloc_str, "%2.2f%% %s", percent, str) < 0)
+					str = "Not enough memory!";
+				else
+					str = alloc_str;
+			}
+
+			color = HE_COLORSET_NORMAL;
+			width = self->b.width - (offset + extra_offset + 2);
+			if (ui_browser__is_current_entry(&self->b, row)) {
+				self->selection = &chain->ms;
+				color = HE_COLORSET_SELECTED;
+				*is_current_entry = true;
+			}
+
+			ui_browser__set_color(&self->b, color);
+			ui_browser__gotorc(&self->b, row, 0);
+			slsmg_write_nstring(" ", offset + extra_offset);
+			slsmg_printf("%c ", folded_sign);
+			slsmg_write_nstring(str, width);
+			free(alloc_str);
+
+			if (++row == self->b.height)
+				goto out;
+do_next:
+			if (folded_sign == '+')
+				break;
+		}
+
+		if (folded_sign == '-') {
+			const int new_level = level + (extra_offset ? 2 : 1);
+			row += hist_browser__show_callchain_node_rb_tree(self, child, new_total,
+									 new_level, row, row_offset,
+									 is_current_entry);
+		}
+		if (row == self->b.height)
+			goto out;
+		node = next;
+	}
+out:
+	return row - first_row;
+}
+
+static int hist_browser__show_callchain_node(struct hist_browser *self,
+					     struct callchain_node *node,
+					     int level, unsigned short row,
+					     off_t *row_offset,
+					     bool *is_current_entry)
+{
+	struct callchain_list *chain;
+	int first_row = row,
+	     offset = level * LEVEL_OFFSET_STEP,
+	     width = self->b.width - offset;
+	char folded_sign = ' ';
+
+	list_for_each_entry(chain, &node->val, list) {
+		char ipstr[BITS_PER_LONG / 4 + 1], *s;
+		int color;
+
+		folded_sign = callchain_list__folded(chain);
+
+		if (*row_offset != 0) {
+			--*row_offset;
+			continue;
+		}
+
+		color = HE_COLORSET_NORMAL;
+		if (ui_browser__is_current_entry(&self->b, row)) {
+			self->selection = &chain->ms;
+			color = HE_COLORSET_SELECTED;
+			*is_current_entry = true;
+		}
+
+		s = callchain_list__sym_name(chain, ipstr, sizeof(ipstr));
+		ui_browser__gotorc(&self->b, row, 0);
+		ui_browser__set_color(&self->b, color);
+		slsmg_write_nstring(" ", offset);
+		slsmg_printf("%c ", folded_sign);
+		slsmg_write_nstring(s, width - 2);
+
+		if (++row == self->b.height)
+			goto out;
+	}
+
+	if (folded_sign == '-')
+		row += hist_browser__show_callchain_node_rb_tree(self, node,
+								 self->hists->stats.total_period,
+								 level + 1, row,
+								 row_offset,
+								 is_current_entry);
+out:
+	return row - first_row;
+}
+
+static int hist_browser__show_callchain(struct hist_browser *self,
+					struct rb_root *chain,
+					int level, unsigned short row,
+					off_t *row_offset,
+					bool *is_current_entry)
+{
+	struct rb_node *nd;
+	int first_row = row;
+
+	for (nd = rb_first(chain); nd; nd = rb_next(nd)) {
+		struct callchain_node *node = rb_entry(nd, struct callchain_node, rb_node);
+
+		row += hist_browser__show_callchain_node(self, node, level,
+							 row, row_offset,
+							 is_current_entry);
+		if (row == self->b.height)
+			break;
+	}
+
+	return row - first_row;
+}
+
+static int hist_browser__show_entry(struct hist_browser *self,
+				    struct hist_entry *entry,
+				    unsigned short row)
+{
+	char s[256];
+	double percent;
+	int printed = 0;
+	int width = self->b.width - 6; /* The percentage */
+	char folded_sign = ' ';
+	bool current_entry = ui_browser__is_current_entry(&self->b, row);
+	off_t row_offset = entry->row_offset;
+
+	if (current_entry) {
+		self->he_selection = entry;
+		self->selection = &entry->ms;
+	}
+
+	if (symbol_conf.use_callchain) {
+		hist_entry__init_have_children(entry);
+		folded_sign = hist_entry__folded(entry);
+	}
+
+	if (row_offset == 0) {
+		hist_entry__snprintf(entry, s, sizeof(s), self->hists);
+		percent = (entry->period * 100.0) / self->hists->stats.total_period;
+
+		ui_browser__set_percent_color(&self->b, percent, current_entry);
+		ui_browser__gotorc(&self->b, row, 0);
+		if (symbol_conf.use_callchain) {
+			slsmg_printf("%c ", folded_sign);
+			width -= 2;
+		}
+
+		slsmg_printf(" %5.2f%%", percent);
+
+		/* The scroll bar isn't being used */
+		if (!self->b.navkeypressed)
+			width += 1;
+
+		if (!current_entry || !self->b.navkeypressed)
+			ui_browser__set_color(&self->b, HE_COLORSET_NORMAL);
+
+		if (symbol_conf.show_nr_samples) {
+			slsmg_printf(" %11u", entry->nr_events);
+			width -= 12;
+		}
+
+		if (symbol_conf.show_total_period) {
+			slsmg_printf(" %12" PRIu64, entry->period);
+			width -= 13;
+		}
+
+		slsmg_write_nstring(s, width);
+		++row;
+		++printed;
+	} else
+		--row_offset;
+
+	if (folded_sign == '-' && row != self->b.height) {
+		printed += hist_browser__show_callchain(self, &entry->sorted_chain,
+							1, row, &row_offset,
+							&current_entry);
+		if (current_entry)
+			self->he_selection = entry;
+	}
+
+	return printed;
+}
+
+static void ui_browser__hists_init_top(struct ui_browser *browser)
+{
+	if (browser->top == NULL) {
+		struct hist_browser *hb;
+
+		hb = container_of(browser, struct hist_browser, b);
+		browser->top = rb_first(&hb->hists->entries);
+	}
+}
+
+static unsigned int hist_browser__refresh(struct ui_browser *self)
+{
+	unsigned row = 0;
+	struct rb_node *nd;
+	struct hist_browser *hb = container_of(self, struct hist_browser, b);
+
+	ui_browser__hists_init_top(self);
+
+	for (nd = self->top; nd; nd = rb_next(nd)) {
+		struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);
+
+		if (h->filtered)
+			continue;
+
+		row += hist_browser__show_entry(hb, h, row);
+		if (row == self->height)
+			break;
+	}
+
+	return row;
+}
+
+static struct rb_node *hists__filter_entries(struct rb_node *nd)
+{
+	while (nd != NULL) {
+		struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);
+		if (!h->filtered)
+			return nd;
+
+		nd = rb_next(nd);
+	}
+
+	return NULL;
+}
+
+static struct rb_node *hists__filter_prev_entries(struct rb_node *nd)
+{
+	while (nd != NULL) {
+		struct hist_entry *h = rb_entry(nd, struct hist_entry, rb_node);
+		if (!h->filtered)
+			return nd;
+
+		nd = rb_prev(nd);
+	}
+
+	return NULL;
+}
+
+static void ui_browser__hists_seek(struct ui_browser *self,
+				   off_t offset, int whence)
+{
+	struct hist_entry *h;
+	struct rb_node *nd;
+	bool first = true;
+
+	if (self->nr_entries == 0)
+		return;
+
+	ui_browser__hists_init_top(self);
+
+	switch (whence) {
+	case SEEK_SET:
+		nd = hists__filter_entries(rb_first(self->entries));
+		break;
+	case SEEK_CUR:
+		nd = self->top;
+		goto do_offset;
+	case SEEK_END:
+		nd = hists__filter_prev_entries(rb_last(self->entries));
+		first = false;
+		break;
+	default:
+		return;
+	}
+
+	/*
+	 * Moves not relative to the first visible entry invalidates its
+	 * row_offset:
+	 */
+	h = rb_entry(self->top, struct hist_entry, rb_node);
+	h->row_offset = 0;
+
+	/*
+	 * Here we have to check if nd is expanded (+), if it is we can't go
+	 * the next top level hist_entry, instead we must compute an offset of
+	 * what _not_ to show and not change the first visible entry.
+	 *
+	 * This offset increments when we are going from top to bottom and
+	 * decreases when we're going from bottom to top.
+	 *
+	 * As we don't have backpointers to the top level in the callchains
+	 * structure, we need to always print the whole hist_entry callchain,
+	 * skipping the first ones that are before the first visible entry
+	 * and stop when we printed enough lines to fill the screen.
+	 */
+do_offset:
+	if (offset > 0) {
+		do {
+			h = rb_entry(nd, struct hist_entry, rb_node);
+			if (h->ms.unfolded) {
+				u16 remaining = h->nr_rows - h->row_offset;
+				if (offset > remaining) {
+					offset -= remaining;
+					h->row_offset = 0;
+				} else {
+					h->row_offset += offset;
+					offset = 0;
+					self->top = nd;
+					break;
+				}
+			}
+			nd = hists__filter_entries(rb_next(nd));
+			if (nd == NULL)
+				break;
+			--offset;
+			self->top = nd;
+		} while (offset != 0);
+	} else if (offset < 0) {
+		while (1) {
+			h = rb_entry(nd, struct hist_entry, rb_node);
+			if (h->ms.unfolded) {
+				if (first) {
+					if (-offset > h->row_offset) {
+						offset += h->row_offset;
+						h->row_offset = 0;
+					} else {
+						h->row_offset += offset;
+						offset = 0;
+						self->top = nd;
+						break;
+					}
+				} else {
+					if (-offset > h->nr_rows) {
+						offset += h->nr_rows;
+						h->row_offset = 0;
+					} else {
+						h->row_offset = h->nr_rows + offset;
+						offset = 0;
+						self->top = nd;
+						break;
+					}
+				}
+			}
+
+			nd = hists__filter_prev_entries(rb_prev(nd));
+			if (nd == NULL)
+				break;
+			++offset;
+			self->top = nd;
+			if (offset == 0) {
+				/*
+				 * Last unfiltered hist_entry, check if it is
+				 * unfolded, if it is then we should have
+				 * row_offset at its last entry.
+				 */
+				h = rb_entry(nd, struct hist_entry, rb_node);
+				if (h->ms.unfolded)
+					h->row_offset = h->nr_rows;
+				break;
+			}
+			first = false;
+		}
+	} else {
+		self->top = nd;
+		h = rb_entry(nd, struct hist_entry, rb_node);
+		h->row_offset = 0;
+	}
+}
+
+static struct hist_browser *hist_browser__new(struct hists *hists)
+{
+	struct hist_browser *self = zalloc(sizeof(*self));
+
+	if (self) {
+		self->hists = hists;
+		self->b.refresh = hist_browser__refresh;
+		self->b.seek = ui_browser__hists_seek;
+		self->b.use_navkeypressed = true;
+		if (sort__branch_mode == 1)
+			self->has_symbols = sort_sym_from.list.next != NULL;
+		else
+			self->has_symbols = sort_sym.list.next != NULL;
+	}
+
+	return self;
+}
+
+static void hist_browser__delete(struct hist_browser *self)
+{
+	free(self);
+}
+
+static struct hist_entry *hist_browser__selected_entry(struct hist_browser *self)
+{
+	return self->he_selection;
+}
+
+static struct thread *hist_browser__selected_thread(struct hist_browser *self)
+{
+	return self->he_selection->thread;
+}
+
+static int hists__browser_title(struct hists *self, char *bf, size_t size,
+				const char *ev_name)
+{
+	char unit;
+	int printed;
+	const struct dso *dso = self->dso_filter;
+	const struct thread *thread = self->thread_filter;
+	unsigned long nr_samples = self->stats.nr_events[PERF_RECORD_SAMPLE];
+	u64 nr_events = self->stats.total_period;
+
+	nr_samples = convert_unit(nr_samples, &unit);
+	printed = scnprintf(bf, size,
+			   "Samples: %lu%c of event '%s', Event count (approx.): %lu",
+			   nr_samples, unit, ev_name, nr_events);
+
+
+	if (self->uid_filter_str)
+		printed += snprintf(bf + printed, size - printed,
+				    ", UID: %s", self->uid_filter_str);
+	if (thread)
+		printed += scnprintf(bf + printed, size - printed,
+				    ", Thread: %s(%d)",
+				    (thread->comm_set ? thread->comm : ""),
+				    thread->pid);
+	if (dso)
+		printed += scnprintf(bf + printed, size - printed,
+				    ", DSO: %s", dso->short_name);
+	return printed;
+}
+
+static inline void free_popup_options(char **options, int n)
+{
+	int i;
+
+	for (i = 0; i < n; ++i) {
+		free(options[i]);
+		options[i] = NULL;
+	}
+}
+
+static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
+				    const char *helpline, const char *ev_name,
+				    bool left_exits,
+				    void(*timer)(void *arg), void *arg,
+				    int delay_secs)
+{
+	struct hists *self = &evsel->hists;
+	struct hist_browser *browser = hist_browser__new(self);
+	struct branch_info *bi;
+	struct pstack *fstack;
+	char *options[16];
+	int nr_options = 0;
+	int key = -1;
+	char buf[64];
+
+	if (browser == NULL)
+		return -1;
+
+	fstack = pstack__new(2);
+	if (fstack == NULL)
+		goto out;
+
+	ui_helpline__push(helpline);
+
+	memset(options, 0, sizeof(options));
+
+	while (1) {
+		const struct thread *thread = NULL;
+		const struct dso *dso = NULL;
+		int choice = 0,
+		    annotate = -2, zoom_dso = -2, zoom_thread = -2,
+		    annotate_f = -2, annotate_t = -2, browse_map = -2;
+
+		nr_options = 0;
+
+		key = hist_browser__run(browser, ev_name, timer, arg, delay_secs);
+
+		if (browser->he_selection != NULL) {
+			thread = hist_browser__selected_thread(browser);
+			dso = browser->selection->map ? browser->selection->map->dso : NULL;
+		}
+		switch (key) {
+		case K_TAB:
+		case K_UNTAB:
+			if (nr_events == 1)
+				continue;
+			/*
+			 * Exit the browser, let hists__browser_tree
+			 * go to the next or previous
+			 */
+			goto out_free_stack;
+		case 'a':
+			if (!browser->has_symbols) {
+				ui_browser__warning(&browser->b, delay_secs * 2,
+			"Annotation is only available for symbolic views, "
+			"include \"sym*\" in --sort to use it.");
+				continue;
+			}
+
+			if (browser->selection == NULL ||
+			    browser->selection->sym == NULL ||
+			    browser->selection->map->dso->annotate_warned)
+				continue;
+			goto do_annotate;
+		case 'd':
+			goto zoom_dso;
+		case 't':
+			goto zoom_thread;
+		case 's':
+			if (ui_browser__input_window("Symbol to show",
+					"Please enter the name of symbol you want to see",
+					buf, "ENTER: OK, ESC: Cancel",
+					delay_secs * 2) == K_ENTER) {
+				self->symbol_filter_str = *buf ? buf : NULL;
+				hists__filter_by_symbol(self);
+				hist_browser__reset(browser);
+			}
+			continue;
+		case K_F1:
+		case 'h':
+		case '?':
+			ui_browser__help_window(&browser->b,
+					"h/?/F1        Show this window\n"
+					"UP/DOWN/PGUP\n"
+					"PGDN/SPACE    Navigate\n"
+					"q/ESC/CTRL+C  Exit browser\n\n"
+					"For multiple event sessions:\n\n"
+					"TAB/UNTAB Switch events\n\n"
+					"For symbolic views (--sort has sym):\n\n"
+					"->            Zoom into DSO/Threads & Annotate current symbol\n"
+					"<-            Zoom out\n"
+					"a             Annotate current symbol\n"
+					"C             Collapse all callchains\n"
+					"E             Expand all callchains\n"
+					"d             Zoom into current DSO\n"
+					"t             Zoom into current Thread\n"
+					"s             Filter symbol by name");
+			continue;
+		case K_ENTER:
+		case K_RIGHT:
+			/* menu */
+			break;
+		case K_LEFT: {
+			const void *top;
+
+			if (pstack__empty(fstack)) {
+				/*
+				 * Go back to the perf_evsel_menu__run or other user
+				 */
+				if (left_exits)
+					goto out_free_stack;
+				continue;
+			}
+			top = pstack__pop(fstack);
+			if (top == &browser->hists->dso_filter)
+				goto zoom_out_dso;
+			if (top == &browser->hists->thread_filter)
+				goto zoom_out_thread;
+			continue;
+		}
+		case K_ESC:
+			if (!left_exits &&
+			    !ui_browser__dialog_yesno(&browser->b,
+					       "Do you really want to exit?"))
+				continue;
+			/* Fall thru */
+		case 'q':
+		case CTRL('c'):
+			goto out_free_stack;
+		default:
+			continue;
+		}
+
+		if (!browser->has_symbols)
+			goto add_exit_option;
+
+		if (sort__branch_mode == 1) {
+			bi = browser->he_selection->branch_info;
+			if (browser->selection != NULL &&
+			    bi &&
+			    bi->from.sym != NULL &&
+			    !bi->from.map->dso->annotate_warned &&
+				asprintf(&options[nr_options], "Annotate %s",
+					 bi->from.sym->name) > 0)
+				annotate_f = nr_options++;
+
+			if (browser->selection != NULL &&
+			    bi &&
+			    bi->to.sym != NULL &&
+			    !bi->to.map->dso->annotate_warned &&
+			    (bi->to.sym != bi->from.sym ||
+			     bi->to.map->dso != bi->from.map->dso) &&
+				asprintf(&options[nr_options], "Annotate %s",
+					 bi->to.sym->name) > 0)
+				annotate_t = nr_options++;
+		} else {
+
+			if (browser->selection != NULL &&
+			    browser->selection->sym != NULL &&
+			    !browser->selection->map->dso->annotate_warned &&
+				asprintf(&options[nr_options], "Annotate %s",
+					 browser->selection->sym->name) > 0)
+				annotate = nr_options++;
+		}
+
+		if (thread != NULL &&
+		    asprintf(&options[nr_options], "Zoom %s %s(%d) thread",
+			     (browser->hists->thread_filter ? "out of" : "into"),
+			     (thread->comm_set ? thread->comm : ""),
+			     thread->pid) > 0)
+			zoom_thread = nr_options++;
+
+		if (dso != NULL &&
+		    asprintf(&options[nr_options], "Zoom %s %s DSO",
+			     (browser->hists->dso_filter ? "out of" : "into"),
+			     (dso->kernel ? "the Kernel" : dso->short_name)) > 0)
+			zoom_dso = nr_options++;
+
+		if (browser->selection != NULL &&
+		    browser->selection->map != NULL &&
+		    asprintf(&options[nr_options], "Browse map details") > 0)
+			browse_map = nr_options++;
+add_exit_option:
+		options[nr_options++] = (char *)"Exit";
+retry_popup_menu:
+		choice = ui__popup_menu(nr_options, options);
+
+		if (choice == nr_options - 1)
+			break;
+
+		if (choice == -1) {
+			free_popup_options(options, nr_options - 1);
+			continue;
+		}
+
+		if (choice == annotate || choice == annotate_t || choice == annotate_f) {
+			struct hist_entry *he;
+			int err;
+do_annotate:
+			he = hist_browser__selected_entry(browser);
+			if (he == NULL)
+				continue;
+
+			/*
+			 * we stash the branch_info symbol + map into the
+			 * the ms so we don't have to rewrite all the annotation
+			 * code to use branch_info.
+			 * in branch mode, the ms struct is not used
+			 */
+			if (choice == annotate_f) {
+				he->ms.sym = he->branch_info->from.sym;
+				he->ms.map = he->branch_info->from.map;
+			}  else if (choice == annotate_t) {
+				he->ms.sym = he->branch_info->to.sym;
+				he->ms.map = he->branch_info->to.map;
+			}
+
+			/*
+			 * Don't let this be freed, say, by hists__decay_entry.
+			 */
+			he->used = true;
+			err = hist_entry__tui_annotate(he, evsel->idx,
+						       timer, arg, delay_secs);
+			he->used = false;
+			/*
+			 * offer option to annotate the other branch source or target
+			 * (if they exists) when returning from annotate
+			 */
+			if ((err == 'q' || err == CTRL('c'))
+			    && annotate_t != -2 && annotate_f != -2)
+				goto retry_popup_menu;
+
+			ui_browser__update_nr_entries(&browser->b, browser->hists->nr_entries);
+			if (err)
+				ui_browser__handle_resize(&browser->b);
+
+		} else if (choice == browse_map)
+			map__browse(browser->selection->map);
+		else if (choice == zoom_dso) {
+zoom_dso:
+			if (browser->hists->dso_filter) {
+				pstack__remove(fstack, &browser->hists->dso_filter);
+zoom_out_dso:
+				ui_helpline__pop();
+				browser->hists->dso_filter = NULL;
+				sort_dso.elide = false;
+			} else {
+				if (dso == NULL)
+					continue;
+				ui_helpline__fpush("To zoom out press <- or -> + \"Zoom out of %s DSO\"",
+						   dso->kernel ? "the Kernel" : dso->short_name);
+				browser->hists->dso_filter = dso;
+				sort_dso.elide = true;
+				pstack__push(fstack, &browser->hists->dso_filter);
+			}
+			hists__filter_by_dso(self);
+			hist_browser__reset(browser);
+		} else if (choice == zoom_thread) {
+zoom_thread:
+			if (browser->hists->thread_filter) {
+				pstack__remove(fstack, &browser->hists->thread_filter);
+zoom_out_thread:
+				ui_helpline__pop();
+				browser->hists->thread_filter = NULL;
+				sort_thread.elide = false;
+			} else {
+				ui_helpline__fpush("To zoom out press <- or -> + \"Zoom out of %s(%d) thread\"",
+						   thread->comm_set ? thread->comm : "",
+						   thread->pid);
+				browser->hists->thread_filter = thread;
+				sort_thread.elide = true;
+				pstack__push(fstack, &browser->hists->thread_filter);
+			}
+			hists__filter_by_thread(self);
+			hist_browser__reset(browser);
+		}
+	}
+out_free_stack:
+	pstack__delete(fstack);
+out:
+	hist_browser__delete(browser);
+	free_popup_options(options, nr_options - 1);
+	return key;
+}
+
+struct perf_evsel_menu {
+	struct ui_browser b;
+	struct perf_evsel *selection;
+	bool lost_events, lost_events_warned;
+};
+
+static void perf_evsel_menu__write(struct ui_browser *browser,
+				   void *entry, int row)
+{
+	struct perf_evsel_menu *menu = container_of(browser,
+						    struct perf_evsel_menu, b);
+	struct perf_evsel *evsel = list_entry(entry, struct perf_evsel, node);
+	bool current_entry = ui_browser__is_current_entry(browser, row);
+	unsigned long nr_events = evsel->hists.stats.nr_events[PERF_RECORD_SAMPLE];
+	const char *ev_name = event_name(evsel);
+	char bf[256], unit;
+	const char *warn = " ";
+	size_t printed;
+
+	ui_browser__set_color(browser, current_entry ? HE_COLORSET_SELECTED :
+						       HE_COLORSET_NORMAL);
+
+	nr_events = convert_unit(nr_events, &unit);
+	printed = scnprintf(bf, sizeof(bf), "%lu%c%s%s", nr_events,
+			   unit, unit == ' ' ? "" : " ", ev_name);
+	slsmg_printf("%s", bf);
+
+	nr_events = evsel->hists.stats.nr_events[PERF_RECORD_LOST];
+	if (nr_events != 0) {
+		menu->lost_events = true;
+		if (!current_entry)
+			ui_browser__set_color(browser, HE_COLORSET_TOP);
+		nr_events = convert_unit(nr_events, &unit);
+		printed += scnprintf(bf, sizeof(bf), ": %ld%c%schunks LOST!",
+				     nr_events, unit, unit == ' ' ? "" : " ");
+		warn = bf;
+	}
+
+	slsmg_write_nstring(warn, browser->width - printed);
+
+	if (current_entry)
+		menu->selection = evsel;
+}
+
+static int perf_evsel_menu__run(struct perf_evsel_menu *menu,
+				int nr_events, const char *help,
+				void(*timer)(void *arg), void *arg, int delay_secs)
+{
+	struct perf_evlist *evlist = menu->b.priv;
+	struct perf_evsel *pos;
+	const char *ev_name, *title = "Available samples";
+	int key;
+
+	if (ui_browser__show(&menu->b, title,
+			     "ESC: exit, ENTER|->: Browse histograms") < 0)
+		return -1;
+
+	while (1) {
+		key = ui_browser__run(&menu->b, delay_secs);
+
+		switch (key) {
+		case K_TIMER:
+			timer(arg);
+
+			if (!menu->lost_events_warned && menu->lost_events) {
+				ui_browser__warn_lost_events(&menu->b);
+				menu->lost_events_warned = true;
+			}
+			continue;
+		case K_RIGHT:
+		case K_ENTER:
+			if (!menu->selection)
+				continue;
+			pos = menu->selection;
+browse_hists:
+			perf_evlist__set_selected(evlist, pos);
+			/*
+			 * Give the calling tool a chance to populate the non
+			 * default evsel resorted hists tree.
+			 */
+			if (timer)
+				timer(arg);
+			ev_name = event_name(pos);
+			key = perf_evsel__hists_browse(pos, nr_events, help,
+						       ev_name, true, timer,
+						       arg, delay_secs);
+			ui_browser__show_title(&menu->b, title);
+			switch (key) {
+			case K_TAB:
+				if (pos->node.next == &evlist->entries)
+					pos = list_entry(evlist->entries.next, struct perf_evsel, node);
+				else
+					pos = list_entry(pos->node.next, struct perf_evsel, node);
+				goto browse_hists;
+			case K_UNTAB:
+				if (pos->node.prev == &evlist->entries)
+					pos = list_entry(evlist->entries.prev, struct perf_evsel, node);
+				else
+					pos = list_entry(pos->node.prev, struct perf_evsel, node);
+				goto browse_hists;
+			case K_ESC:
+				if (!ui_browser__dialog_yesno(&menu->b,
+						"Do you really want to exit?"))
+					continue;
+				/* Fall thru */
+			case 'q':
+			case CTRL('c'):
+				goto out;
+			default:
+				continue;
+			}
+		case K_LEFT:
+			continue;
+		case K_ESC:
+			if (!ui_browser__dialog_yesno(&menu->b,
+					       "Do you really want to exit?"))
+				continue;
+			/* Fall thru */
+		case 'q':
+		case CTRL('c'):
+			goto out;
+		default:
+			continue;
+		}
+	}
+
+out:
+	ui_browser__hide(&menu->b);
+	return key;
+}
+
+static int __perf_evlist__tui_browse_hists(struct perf_evlist *evlist,
+					   const char *help,
+					   void(*timer)(void *arg), void *arg,
+					   int delay_secs)
+{
+	struct perf_evsel *pos;
+	struct perf_evsel_menu menu = {
+		.b = {
+			.entries    = &evlist->entries,
+			.refresh    = ui_browser__list_head_refresh,
+			.seek	    = ui_browser__list_head_seek,
+			.write	    = perf_evsel_menu__write,
+			.nr_entries = evlist->nr_entries,
+			.priv	    = evlist,
+		},
+	};
+
+	ui_helpline__push("Press ESC to exit");
+
+	list_for_each_entry(pos, &evlist->entries, node) {
+		const char *ev_name = event_name(pos);
+		size_t line_len = strlen(ev_name) + 7;
+
+		if (menu.b.width < line_len)
+			menu.b.width = line_len;
+		/*
+		 * Cache the evsel name, tracepoints have a _high_ cost per
+		 * event_name() call.
+		 */
+		if (pos->name == NULL)
+			pos->name = strdup(ev_name);
+	}
+
+	return perf_evsel_menu__run(&menu, evlist->nr_entries, help, timer,
+				    arg, delay_secs);
+}
+
+int perf_evlist__tui_browse_hists(struct perf_evlist *evlist, const char *help,
+				  void(*timer)(void *arg), void *arg,
+				  int delay_secs)
+{
+
+	if (evlist->nr_entries == 1) {
+		struct perf_evsel *first = list_entry(evlist->entries.next,
+						      struct perf_evsel, node);
+		const char *ev_name = event_name(first);
+		return perf_evsel__hists_browse(first, evlist->nr_entries, help,
+						ev_name, false, timer, arg,
+						delay_secs);
+	}
+
+	return __perf_evlist__tui_browse_hists(evlist, help,
+					       timer, arg, delay_secs);
+}