perf: Keep track of the max depth of a callchain
In order to implement callchains collapsing, we need to keep
track of the maximum depth in a histogram tree of callchains.
This way we'll avoid allocating an arbitrary temporary buffer
size on callchain merge time.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christoph Hellwig <hch@infradead.org>
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 624a96c..9b93a38 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -26,9 +26,14 @@
u64 children_hit;
};
+struct callchain_root {
+ u64 max_depth;
+ struct callchain_node node;
+};
+
struct callchain_param;
-typedef void (*sort_chain_func_t)(struct rb_root *, struct callchain_node *,
+typedef void (*sort_chain_func_t)(struct rb_root *, struct callchain_root *,
u64, struct callchain_param *);
struct callchain_param {
@@ -44,14 +49,15 @@
struct list_head list;
};
-static inline void callchain_init(struct callchain_node *node)
+static inline void callchain_init(struct callchain_root *root)
{
- INIT_LIST_HEAD(&node->brothers);
- INIT_LIST_HEAD(&node->children);
- INIT_LIST_HEAD(&node->val);
+ INIT_LIST_HEAD(&root->node.brothers);
+ INIT_LIST_HEAD(&root->node.children);
+ INIT_LIST_HEAD(&root->node.val);
- node->parent = NULL;
- node->hit = 0;
+ root->node.parent = NULL;
+ root->node.hit = 0;
+ root->max_depth = 0;
}
static inline u64 cumul_hits(struct callchain_node *node)
@@ -60,7 +66,7 @@
}
int register_callchain_param(struct callchain_param *param);
-int append_chain(struct callchain_node *root, struct ip_callchain *chain,
+int append_chain(struct callchain_root *root, struct ip_callchain *chain,
struct map_symbol *syms, u64 period);
bool ip_callchain__valid(struct ip_callchain *chain, const event_t *event);