/*
- * Copyright (C) 2009-2010, Frederic Weisbecker <fweisbec@gmail.com>
+ * 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.
}
-struct resolved_ip {
- u64 ip;
- struct map_symbol ms;
-};
-
-struct resolved_chain {
- u64 nr;
- struct resolved_ip ips[0];
-};
-
-
/*
* Fill the node with callchain values
*/
static void
-fill_node(struct callchain_node *node, struct resolved_chain *chain, int start)
+fill_node(struct callchain_node *node, struct callchain_cursor *cursor)
{
- unsigned int i;
+ 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");
- for (i = start; i < chain->nr; i++) {
+ cursor_node = callchain_cursor_current(cursor);
+
+ while (cursor_node) {
struct callchain_list *call;
call = zalloc(sizeof(*call));
perror("not enough memory for the code path tree");
return;
}
- call->ip = chain->ips[i].ip;
- call->ms = chain->ips[i].ms;
+ 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);
}
- node->val_nr = chain->nr - start;
- if (!node->val_nr)
- pr_warning("Warning: empty node in callchain tree\n");
}
static void
-add_child(struct callchain_node *parent, struct resolved_chain *chain,
- int start, u64 period)
+add_child(struct callchain_node *parent,
+ struct callchain_cursor *cursor,
+ u64 period)
{
struct callchain_node *new;
new = create_child(parent, false);
- fill_node(new, chain, start);
+ fill_node(new, cursor);
new->children_hit = 0;
new->hit = period;
* Then create another child to host the given callchain of new branch
*/
static void
-split_add_child(struct callchain_node *parent, struct resolved_chain *chain,
- struct callchain_list *to_split, int idx_parents, int idx_local,
- u64 period)
+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;
parent->val_nr = idx_local;
/* create a new child for the new branch if any */
- if (idx_total < chain->nr) {
+ if (idx_total < cursor->nr) {
parent->hit = 0;
- add_child(parent, chain, idx_total, period);
+ add_child(parent, cursor, period);
parent->children_hit += period;
} else {
parent->hit = period;
}
static int
-append_chain(struct callchain_node *root, struct resolved_chain *chain,
- unsigned int start, u64 period);
+append_chain(struct callchain_node *root,
+ struct callchain_cursor *cursor,
+ u64 period);
static void
-append_chain_children(struct callchain_node *root, struct resolved_chain *chain,
- unsigned int start, u64 period)
+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, chain, start, period);
+ 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, chain, start, period);
+ add_child(root, cursor, period);
inc_children_hit:
root->children_hit += period;
}
static int
-append_chain(struct callchain_node *root, struct resolved_chain *chain,
- unsigned int start, u64 period)
+append_chain(struct callchain_node *root,
+ struct callchain_cursor *cursor,
+ u64 period)
{
+ struct callchain_cursor_node *curr_snap = cursor->curr;
struct callchain_list *cnode;
- unsigned int i = start;
+ u64 start = cursor->pos;
bool found = false;
+ u64 matches;
/*
* Lookup in the current node
* anywhere inside a function.
*/
list_for_each_entry(cnode, &root->val, list) {
+ struct callchain_cursor_node *node;
struct symbol *sym;
- if (i == chain->nr)
+ node = callchain_cursor_current(cursor);
+ if (!node)
break;
- sym = chain->ips[i].ms.sym;
+ sym = node->sym;
if (cnode->ms.sym && sym) {
if (cnode->ms.sym->start != sym->start)
break;
- } else if (cnode->ip != chain->ips[i].ip)
+ } else if (cnode->ip != node->ip)
break;
if (!found)
found = true;
- i++;
+
+ callchain_cursor_advance(cursor);
}
/* matches not, relay on the parent */
- if (!found)
+ 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 (i - start < root->val_nr) {
- split_add_child(root, chain, cnode, start, i - start, period);
+ 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 (i - start == root->val_nr && i == chain->nr) {
+ 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, chain, i, period);
+ append_chain_children(root, cursor, period);
return 0;
}
-static void filter_context(struct ip_callchain *old, struct resolved_chain *new,
- struct map_symbol *syms)
-{
- int i, j = 0;
-
- for (i = 0; i < (int)old->nr; i++) {
- if (old->ips[i] >= PERF_CONTEXT_MAX)
- continue;
-
- new->ips[j].ip = old->ips[i];
- new->ips[j].ms = syms[i];
- j++;
- }
-
- new->nr = j;
-}
-
-
-int callchain_append(struct callchain_root *root, struct ip_callchain *chain,
- struct map_symbol *syms, u64 period)
+int callchain_append(struct callchain_root *root,
+ struct callchain_cursor *cursor,
+ u64 period)
{
- struct resolved_chain *filtered;
-
- if (!chain->nr)
+ if (!cursor->nr)
return 0;
- filtered = zalloc(sizeof(*filtered) +
- chain->nr * sizeof(struct resolved_ip));
- if (!filtered)
- return -ENOMEM;
-
- filter_context(chain, filtered, syms);
-
- if (!filtered->nr)
- goto end;
+ callchain_cursor_commit(cursor);
- append_chain_children(&root->node, filtered, 0, period);
+ append_chain_children(&root->node, cursor, period);
- if (filtered->nr > root->max_depth)
- root->max_depth = filtered->nr;
-end:
- free(filtered);
+ if (cursor->nr > root->max_depth)
+ root->max_depth = cursor->nr;
return 0;
}
static int
-merge_chain_branch(struct callchain_node *dst, struct callchain_node *src,
- struct resolved_chain *chain)
+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 = chain->nr;
+ int old_pos = cursor->nr;
int err = 0;
list_for_each_entry_safe(list, next_list, &src->val, list) {
- chain->ips[chain->nr].ip = list->ip;
- chain->ips[chain->nr].ms = list->ms;
- chain->nr++;
+ callchain_cursor_append(cursor, list->ip,
+ list->ms.map, list->ms.sym);
list_del(&list->list);
free(list);
}
- if (src->hit)
- append_chain_children(dst, chain, 0, src->hit);
+ 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(dst, child, chain);
+ err = merge_chain_branch(cursor, dst, child);
if (err)
break;
free(child);
}
- chain->nr = old_pos;
+ cursor->nr = old_pos;
+ cursor->last = old_last;
return err;
}
-int callchain_merge(struct callchain_root *dst, struct callchain_root *src)
+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 resolved_chain *chain;
- int err;
+ struct callchain_cursor_node *node = *cursor->last;
- chain = malloc(sizeof(*chain) +
- src->max_depth * sizeof(struct resolved_ip));
- if (!chain)
- return -ENOMEM;
+ if (!node) {
+ node = calloc(sizeof(*node), 1);
+ if (!node)
+ return -ENOMEM;
- chain->nr = 0;
+ *cursor->last = node;
+ }
- err = merge_chain_branch(&dst->node, &src->node, chain);
+ node->ip = ip;
+ node->map = map;
+ node->sym = sym;
- free(chain);
+ cursor->nr++;
- return err;
+ cursor->last = &node->next;
+
+ return 0;
}
struct list_head list;
};
+/*
+ * A callchain cursor is a single linked list that
+ * let one feed a callchain progressively.
+ * It keeps persitent allocated entries to minimize
+ * allocations.
+ */
+struct callchain_cursor_node {
+ u64 ip;
+ struct map *map;
+ struct symbol *sym;
+ struct callchain_cursor_node *next;
+};
+
+struct callchain_cursor {
+ u64 nr;
+ struct callchain_cursor_node *first;
+ struct callchain_cursor_node **last;
+ u64 pos;
+ struct callchain_cursor_node *curr;
+};
+
static inline void callchain_init(struct callchain_root *root)
{
INIT_LIST_HEAD(&root->node.brothers);
}
int register_callchain_param(struct callchain_param *param);
-int callchain_append(struct callchain_root *root, struct ip_callchain *chain,
- struct map_symbol *syms, u64 period);
-int callchain_merge(struct callchain_root *dst, struct callchain_root *src);
+int callchain_append(struct callchain_root *root,
+ struct callchain_cursor *cursor,
+ u64 period);
+
+int callchain_merge(struct callchain_cursor *cursor,
+ struct callchain_root *dst, struct callchain_root *src);
bool ip_callchain__valid(struct ip_callchain *chain, const event_t *event);
+
+/*
+ * Initialize a cursor before adding entries inside, but keep
+ * the previously allocated entries as a cache.
+ */
+static inline void callchain_cursor_reset(struct callchain_cursor *cursor)
+{
+ cursor->nr = 0;
+ cursor->last = &cursor->first;
+}
+
+int callchain_cursor_append(struct callchain_cursor *cursor, u64 ip,
+ struct map *map, struct symbol *sym);
+
+/* Close a cursor writing session. Initialize for the reader */
+static inline void callchain_cursor_commit(struct callchain_cursor *cursor)
+{
+ cursor->curr = cursor->first;
+ cursor->pos = 0;
+}
+
+/* Cursor reading iteration helpers */
+static inline struct callchain_cursor_node *
+callchain_cursor_current(struct callchain_cursor *cursor)
+{
+ if (cursor->pos == cursor->nr)
+ return NULL;
+
+ return cursor->curr;
+}
+
+static inline void callchain_cursor_advance(struct callchain_cursor *cursor)
+{
+ cursor->curr = cursor->curr->next;
+ cursor->pos++;
+}
#endif /* __PERF_CALLCHAIN_H */