1 files changed, 461 insertions, 0 deletions
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
new file mode 100644
index 00000000..9f7106a8
--- /dev/null
+++ b/tools/perf/util/callchain.c
@@ -0,0 +1,461 @@
+/*
+ * Copyright (C) 2009-2011, Frederic Weisbecker <fweisbec@gmail.com>
+ *
+ * Handle the callchains from the stream in an ad-hoc radix tree and then
+ * sort them in an rbtree.
+ *
+ * Using a radix for code path provides a fast retrieval and factorizes
+ * memory use. Also that lets us use the paths in a hierarchical graph view.
+ *
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <math.h>
+
+#include "util.h"
+#include "callchain.h"
+
+bool ip_callchain__valid(struct ip_callchain *chain,
+			 const union perf_event *event)
+{
+	unsigned int chain_size = event->header.size;
+	chain_size -= (unsigned long)&event->ip.__more_data - (unsigned long)event;
+	return chain->nr * sizeof(u64) <= chain_size;
+}
+
+#define chain_for_each_child(child, parent)	\
+	list_for_each_entry(child, &parent->children, siblings)
+
+#define chain_for_each_child_safe(child, next, parent)	\
+	list_for_each_entry_safe(child, next, &parent->children, siblings)
+
+static void
+rb_insert_callchain(struct rb_root *root, struct callchain_node *chain,
+		    enum chain_mode mode)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent = NULL;
+	struct callchain_node *rnode;
+	u64 chain_cumul = callchain_cumul_hits(chain);
+
+	while (*p) {
+		u64 rnode_cumul;
+
+		parent = *p;
+		rnode = rb_entry(parent, struct callchain_node, rb_node);
+		rnode_cumul = callchain_cumul_hits(rnode);
+
+		switch (mode) {
+		case CHAIN_FLAT:
+			if (rnode->hit < chain->hit)
+				p = &(*p)->rb_left;
+			else
+				p = &(*p)->rb_right;
+			break;
+		case CHAIN_GRAPH_ABS: /* Falldown */
+		case CHAIN_GRAPH_REL:
+			if (rnode_cumul < chain_cumul)
+				p = &(*p)->rb_left;
+			else
+				p = &(*p)->rb_right;
+			break;
+		case CHAIN_NONE:
+		default:
+			break;
+		}
+	}
+
+	rb_link_node(&chain->rb_node, parent, p);
+	rb_insert_color(&chain->rb_node, root);
+}
+
+static void
+__sort_chain_flat(struct rb_root *rb_root, struct callchain_node *node,
+		  u64 min_hit)
+{
+	struct callchain_node *child;
+
+	chain_for_each_child(child, node)
+		__sort_chain_flat(rb_root, child, min_hit);
+
+	if (node->hit && node->hit >= min_hit)
+		rb_insert_callchain(rb_root, node, CHAIN_FLAT);
+}
+
+/*
+ * Once we get every callchains from the stream, we can now
+ * sort them by hit
+ */
+static void
+sort_chain_flat(struct rb_root *rb_root, struct callchain_root *root,
+		u64 min_hit, struct callchain_param *param __used)
+{
+	__sort_chain_flat(rb_root, &root->node, min_hit);
+}
+
+static void __sort_chain_graph_abs(struct callchain_node *node,
+				   u64 min_hit)
+{
+	struct callchain_node *child;
+
+	node->rb_root = RB_ROOT;
+
+	chain_for_each_child(child, node) {
+		__sort_chain_graph_abs(child, min_hit);
+		if (callchain_cumul_hits(child) >= min_hit)
+			rb_insert_callchain(&node->rb_root, child,
+					    CHAIN_GRAPH_ABS);
+	}
+}
+
+static void
+sort_chain_graph_abs(struct rb_root *rb_root, struct callchain_root *chain_root,
+		     u64 min_hit, struct callchain_param *param __used)
+{
+	__sort_chain_graph_abs(&chain_root->node, min_hit);
+	rb_root->rb_node = chain_root->node.rb_root.rb_node;
+}
+
+static void __sort_chain_graph_rel(struct callchain_node *node,
+				   double min_percent)
+{
+	struct callchain_node *child;
+	u64 min_hit;
+
+	node->rb_root = RB_ROOT;
+	min_hit = ceil(node->children_hit * min_percent);
+
+	chain_for_each_child(child, node) {
+		__sort_chain_graph_rel(child, min_percent);
+		if (callchain_cumul_hits(child) >= min_hit)
+			rb_insert_callchain(&node->rb_root, child,
+					    CHAIN_GRAPH_REL);
+	}
+}
+
+static void
+sort_chain_graph_rel(struct rb_root *rb_root, struct callchain_root *chain_root,
+		     u64 min_hit __used, struct callchain_param *param)
+{
+	__sort_chain_graph_rel(&chain_root->node, param->min_percent / 100.0);
+	rb_root->rb_node = chain_root->node.rb_root.rb_node;
+}
+
+int callchain_register_param(struct callchain_param *param)
+{
+	switch (param->mode) {
+	case CHAIN_GRAPH_ABS:
+		param->sort = sort_chain_graph_abs;
+		break;
+	case CHAIN_GRAPH_REL:
+		param->sort = sort_chain_graph_rel;
+		break;
+	case CHAIN_FLAT:
+		param->sort = sort_chain_flat;
+		break;
+	case CHAIN_NONE:
+	default:
+		return -1;
+	}
+	return 0;
+}
+
+/*
+ * Create a child for a parent. If inherit_children, then the new child
+ * will become the new parent of it's parent children
+ */
+static struct callchain_node *
+create_child(struct callchain_node *parent, bool inherit_children)
+{
+	struct callchain_node *new;
+
+	new = zalloc(sizeof(*new));
+	if (!new) {
+		perror("not enough memory to create child for code path tree");
+		return NULL;
+	}
+	new->parent = parent;
+	INIT_LIST_HEAD(&new->children);
+	INIT_LIST_HEAD(&new->val);
+
+	if (inherit_children) {
+		struct callchain_node *next;
+
+		list_splice(&parent->children, &new->children);
+		INIT_LIST_HEAD(&parent->children);
+
+		chain_for_each_child(next, new)
+			next->parent = new;
+	}
+	list_add_tail(&new->siblings, &parent->children);
+
+	return new;
+}
+
+
+/*
+ * Fill the node with callchain values
+ */
+static void
+fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
+{
+	struct callchain_cursor_node *cursor_node;
+
+	node->val_nr = cursor->nr - cursor->pos;
+	if (!node->val_nr)
+		pr_warning("Warning: empty node in callchain tree\n");
+
+	cursor_node = callchain_cursor_current(cursor);
+
+	while (cursor_node) {
+		struct callchain_list *call;
+
+		call = zalloc(sizeof(*call));
+		if (!call) {
+			perror("not enough memory for the code path tree");
+			return;
+		}
+		call->ip = cursor_node->ip;
+		call->ms.sym = cursor_node->sym;
+		call->ms.map = cursor_node->map;
+		list_add_tail(&call->list, &node->val);
+
+		callchain_cursor_advance(cursor);
+		cursor_node = callchain_cursor_current(cursor);
+	}
+}
+
+static void
+add_child(struct callchain_node *parent,
+	  struct callchain_cursor *cursor,
+	  u64 period)
+{
+	struct callchain_node *new;
+
+	new = create_child(parent, false);
+	fill_node(new, cursor);
+
+	new->children_hit = 0;
+	new->hit = period;
+}
+
+/*
+ * Split the parent in two parts (a new child is created) and
+ * give a part of its callchain to the created child.
+ * Then create another child to host the given callchain of new branch
+ */
+static void
+split_add_child(struct callchain_node *parent,
+		struct callchain_cursor *cursor,
+		struct callchain_list *to_split,
+		u64 idx_parents, u64 idx_local, u64 period)
+{
+	struct callchain_node *new;
+	struct list_head *old_tail;
+	unsigned int idx_total = idx_parents + idx_local;
+
+	/* split */
+	new = create_child(parent, true);
+
+	/* split the callchain and move a part to the new child */
+	old_tail = parent->val.prev;
+	list_del_range(&to_split->list, old_tail);
+	new->val.next = &to_split->list;
+	new->val.prev = old_tail;
+	to_split->list.prev = &new->val;
+	old_tail->next = &new->val;
+
+	/* split the hits */
+	new->hit = parent->hit;
+	new->children_hit = parent->children_hit;
+	parent->children_hit = callchain_cumul_hits(new);
+	new->val_nr = parent->val_nr - idx_local;
+	parent->val_nr = idx_local;
+
+	/* create a new child for the new branch if any */
+	if (idx_total < cursor->nr) {
+		parent->hit = 0;
+		add_child(parent, cursor, period);
+		parent->children_hit += period;
+	} else {
+		parent->hit = period;
+	}
+}
+
+static int
+append_chain(struct callchain_node *root,
+	     struct callchain_cursor *cursor,
+	     u64 period);
+
+static void
+append_chain_children(struct callchain_node *root,
+		      struct callchain_cursor *cursor,
+		      u64 period)
+{
+	struct callchain_node *rnode;
+
+	/* lookup in childrens */
+	chain_for_each_child(rnode, root) {
+		unsigned int ret = append_chain(rnode, cursor, period);
+
+		if (!ret)
+			goto inc_children_hit;
+	}
+	/* nothing in children, add to the current node */
+	add_child(root, cursor, period);
+
+inc_children_hit:
+	root->children_hit += period;
+}
+
+static int
+append_chain(struct callchain_node *root,
+	     struct callchain_cursor *cursor,
+	     u64 period)
+{
+	struct callchain_cursor_node *curr_snap = cursor->curr;
+	struct callchain_list *cnode;
+	u64 start = cursor->pos;
+	bool found = false;
+	u64 matches;
+
+	/*
+	 * Lookup in the current node
+	 * If we have a symbol, then compare the start to match
+	 * anywhere inside a function.
+	 */
+	list_for_each_entry(cnode, &root->val, list) {
+		struct callchain_cursor_node *node;
+		struct symbol *sym;
+
+		node = callchain_cursor_current(cursor);
+		if (!node)
+			break;
+
+		sym = node->sym;
+
+		if (cnode->ms.sym && sym) {
+			if (cnode->ms.sym->start != sym->start)
+				break;
+		} else if (cnode->ip != node->ip)
+			break;
+
+		if (!found)
+			found = true;
+
+		callchain_cursor_advance(cursor);
+	}
+
+	/* matches not, relay on the parent */
+	if (!found) {
+		cursor->curr = curr_snap;
+		cursor->pos = start;
+		return -1;
+	}
+
+	matches = cursor->pos - start;
+
+	/* we match only a part of the node. Split it and add the new chain */
+	if (matches < root->val_nr) {
+		split_add_child(root, cursor, cnode, start, matches, period);
+		return 0;
+	}
+
+	/* we match 100% of the path, increment the hit */
+	if (matches == root->val_nr && cursor->pos == cursor->nr) {
+		root->hit += period;
+		return 0;
+	}
+
+	/* We match the node and still have a part remaining */
+	append_chain_children(root, cursor, period);
+
+	return 0;
+}
+
+int callchain_append(struct callchain_root *root,
+		     struct callchain_cursor *cursor,
+		     u64 period)
+{
+	if (!cursor->nr)
+		return 0;
+
+	callchain_cursor_commit(cursor);
+
+	append_chain_children(&root->node, cursor, period);
+
+	if (cursor->nr > root->max_depth)
+		root->max_depth = cursor->nr;
+
+	return 0;
+}
+
+static int
+merge_chain_branch(struct callchain_cursor *cursor,
+		   struct callchain_node *dst, struct callchain_node *src)
+{
+	struct callchain_cursor_node **old_last = cursor->last;
+	struct callchain_node *child, *next_child;
+	struct callchain_list *list, *next_list;
+	int old_pos = cursor->nr;
+	int err = 0;
+
+	list_for_each_entry_safe(list, next_list, &src->val, list) {
+		callchain_cursor_append(cursor, list->ip,
+					list->ms.map, list->ms.sym);
+		list_del(&list->list);
+		free(list);
+	}
+
+	if (src->hit) {
+		callchain_cursor_commit(cursor);
+		append_chain_children(dst, cursor, src->hit);
+	}
+
+	chain_for_each_child_safe(child, next_child, src) {
+		err = merge_chain_branch(cursor, dst, child);
+		if (err)
+			break;
+
+		list_del(&child->siblings);
+		free(child);
+	}
+
+	cursor->nr = old_pos;
+	cursor->last = old_last;
+
+	return err;
+}
+
+int callchain_merge(struct callchain_cursor *cursor,
+		    struct callchain_root *dst, struct callchain_root *src)
+{
+	return merge_chain_branch(cursor, &dst->node, &src->node);
+}
+
+int callchain_cursor_append(struct callchain_cursor *cursor,
+			    u64 ip, struct map *map, struct symbol *sym)
+{
+	struct callchain_cursor_node *node = *cursor->last;
+
+	if (!node) {
+		node = calloc(sizeof(*node), 1);
+		if (!node)
+			return -ENOMEM;
+
+		*cursor->last = node;
+	}
+
+	node->ip = ip;
+	node->map = map;
+	node->sym = sym;
+
+	cursor->nr++;
+
+	cursor->last = &node->next;
+
+	return 0;
+}