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-rw-r--r--tools/perf/util/callchain.c335
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 0000000..9d3c814
--- /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);
+}
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