| /* | 
 |  * 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; | 
 | } |