1 files changed, 335 insertions, 0 deletions
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
new file mode 100644
index 000000000000..9d3c8141b8c1
--- /dev/null
+++ b/tools/perf/util/callchain.c
@@ -0,0 +1,335 @@
+/*
+ * Copyright (C) 2009, 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 "callchain.h"
+
+#define chain_for_each_child(child, parent)	\
+	list_for_each_entry(child, &parent->children, brothers)
+
+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;
+
+	while (*p) {
+		parent = *p;
+		rnode = rb_entry(parent, struct callchain_node, rb_node);
+
+		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_hit < chain->cumul_hit)
+				p = &(*p)->rb_left;
+			else
+				p = &(*p)->rb_right;
+			break;
+		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_node *node,
+		u64 min_hit, struct callchain_param *param __used)
+{
+	__sort_chain_flat(rb_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 (child->cumul_hit >= 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_node *chain_root,
+		     u64 min_hit, struct callchain_param *param __used)
+{
+	__sort_chain_graph_abs(chain_root, min_hit);
+	rb_root->rb_node = chain_root->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 = node->cumul_hit * min_percent / 100.0;
+
+	chain_for_each_child(child, node) {
+		__sort_chain_graph_rel(child, min_percent);
+		if (child->cumul_hit >= 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_node *chain_root,
+		     u64 min_hit __used, struct callchain_param *param)
+{
+	__sort_chain_graph_rel(chain_root, param->min_percent);
+	rb_root->rb_node = chain_root->rb_root.rb_node;
+}
+
+int register_callchain_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;
+	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 = malloc(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->brothers, &parent->children);
+
+	return new;
+}
+
+/*
+ * Fill the node with callchain values
+ */
+static void
+fill_node(struct callchain_node *node, struct ip_callchain *chain,
+	  int start, struct symbol **syms)
+{
+	unsigned int i;
+
+	for (i = start; i < chain->nr; i++) {
+		struct callchain_list *call;
+
+		call = malloc(sizeof(*call));
+		if (!call) {
+			perror("not enough memory for the code path tree");
+			return;
+		}
+		call->ip = chain->ips[i];
+		call->sym = syms[i];
+		list_add_tail(&call->list, &node->val);
+	}
+	node->val_nr = chain->nr - start;
+	if (!node->val_nr)
+		printf("Warning: empty node in callchain tree\n");
+}
+
+static void
+add_child(struct callchain_node *parent, struct ip_callchain *chain,
+	  int start, struct symbol **syms)
+{
+	struct callchain_node *new;
+
+	new = create_child(parent, false);
+	fill_node(new, chain, start, syms);
+
+	new->cumul_hit = new->hit = 1;
+}
+
+/*
+ * 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 ip_callchain *chain,
+		struct callchain_list *to_split, int idx_parents, int idx_local,
+		struct symbol **syms)
+{
+	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->cumul_hit = parent->cumul_hit;
+	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 < chain->nr) {
+		parent->hit = 0;
+		add_child(parent, chain, idx_total, syms);
+	} else {
+		parent->hit = 1;
+	}
+}
+
+static int
+__append_chain(struct callchain_node *root, struct ip_callchain *chain,
+	       unsigned int start, struct symbol **syms);
+
+static void
+__append_chain_children(struct callchain_node *root, struct ip_callchain *chain,
+			struct symbol **syms, unsigned int start)
+{
+	struct callchain_node *rnode;
+
+	/* lookup in childrens */
+	chain_for_each_child(rnode, root) {
+		unsigned int ret = __append_chain(rnode, chain, start, syms);
+
+		if (!ret)
+			goto cumul;
+	}
+	/* nothing in children, add to the current node */
+	add_child(root, chain, start, syms);
+
+cumul:
+	root->cumul_hit++;
+}
+
+static int
+__append_chain(struct callchain_node *root, struct ip_callchain *chain,
+	       unsigned int start, struct symbol **syms)
+{
+	struct callchain_list *cnode;
+	unsigned int i = start;
+	bool found = false;
+
+	/*
+	 * 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) {
+		if (i == chain->nr)
+			break;
+		if (cnode->sym && syms[i]) {
+			if (cnode->sym->start != syms[i]->start)
+				break;
+		} else if (cnode->ip != chain->ips[i])
+			break;
+		if (!found)
+			found = true;
+		i++;
+	}
+
+	/* matches not, relay on the parent */
+	if (!found)
+		return -1;
+
+	/* we match only a part of the node. Split it and add the new chain */
+	if (i - start < root->val_nr) {
+		split_add_child(root, chain, cnode, start, i - start, syms);
+		return 0;
+	}
+
+	/* we match 100% of the path, increment the hit */
+	if (i - start == root->val_nr && i == chain->nr) {
+		root->hit++;
+		root->cumul_hit++;
+
+		return 0;
+	}
+
+	/* We match the node and still have a part remaining */
+	__append_chain_children(root, chain, syms, i);
+
+	return 0;
+}
+
+void append_chain(struct callchain_node *root, struct ip_callchain *chain,
+		  struct symbol **syms)
+{
+	__append_chain_children(root, chain, syms, 0);
+}