Avoid using rb_erase when removing symbols as it requires rbtree
rebalancing, instead preform a post order iteration when deleting tree
symbols.
Signed-off-by: Alex Snast <asn...@gmail.com>
---
tools/include/linux/rbtree.h | 14 ++++++++++++++
tools/perf/util/symbol.c | 11 ++++-------
2 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/tools/include/linux/rbtree.h b/tools/include/linux/rbtree.h
index 1125822..14c646d 100644
--- a/tools/include/linux/rbtree.h
+++ b/tools/include/linux/rbtree.h
@@ -90,6 +90,20 @@ static inline void rb_link_node(struct rb_node *node, struct
rb_node *parent,
____ptr ? rb_entry(____ptr, type, member) : NULL; \
})
+/**
+ * rbtree_postorder_for_each_entry_safe - iterate over rb_root in post order of
+ * given type safe against removal of rb_node entry
+ *
+ * @pos: the 'type *' to use as a loop cursor.
+ * @n: another 'type *' to use as temporary storage
+ * @root: 'rb_root *' of the rbtree.
+ * @field: the name of the rb_node field within 'type'.
+ */
+#define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
+ for (pos = rb_entry_safe(rb_first_postorder(root), typeof(*pos),
field); \
+ pos && ({ n = rb_entry_safe(rb_next_postorder(&pos->field), \
+ typeof(*pos), field); 1; }); \
+ pos = n)
/*
* Handy for checking that we are not deleting an entry that is
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 1f97ffb..8b3608c 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -290,15 +290,12 @@ size_t symbol__fprintf_symname(const struct symbol *sym,
FILE *fp)
void symbols__delete(struct rb_root *symbols)
{
- struct symbol *pos;
- struct rb_node *next = rb_first(symbols);
+ struct symbol *pos, *next;
- while (next) {
- pos = rb_entry(next, struct symbol, rb_node);
- next = rb_next(&pos->rb_node);
- rb_erase(&pos->rb_node, symbols);
+ rbtree_postorder_for_each_entry_safe(pos, next, symbols, rb_node)
symbol__delete(pos);
- }
+
+ *symbols = RB_ROOT;
}
void symbols__insert(struct rb_root *symbols, struct symbol *sym)
--
2.1.4
--
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