Commit da27c9ed authored by Uladzislau Rezki (Sony)'s avatar Uladzislau Rezki (Sony) Committed by Linus Torvalds

mm/vmalloc: simplify augment_tree_propagate_check()

This function is for debug purpose only.  Currently it uses recursion for
tree traversal, checking an augmented value of each node to find out if it
is valid or not.

The recursion can corrupt the stack because the tree can be huge if
synthetic tests are applied.  To prevent it, navigate the tree from bottom
to upper levels using a regular list instead, because nodes are linked
among each other also.  It is faster and without recursion.
Signed-off-by: default avatarUladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200527205054.1696-2-urezki@gmail.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5dd78640
...@@ -633,43 +633,17 @@ unlink_va(struct vmap_area *va, struct rb_root *root) ...@@ -633,43 +633,17 @@ unlink_va(struct vmap_area *va, struct rb_root *root)
#if DEBUG_AUGMENT_PROPAGATE_CHECK #if DEBUG_AUGMENT_PROPAGATE_CHECK
static void static void
augment_tree_propagate_check(struct rb_node *n) augment_tree_propagate_check(void)
{ {
struct vmap_area *va; struct vmap_area *va;
struct rb_node *node; unsigned long computed_size;
unsigned long size;
bool found = false;
if (n == NULL)
return;
va = rb_entry(n, struct vmap_area, rb_node);
size = va->subtree_max_size;
node = n;
while (node) {
va = rb_entry(node, struct vmap_area, rb_node);
if (get_subtree_max_size(node->rb_left) == size) {
node = node->rb_left;
} else {
if (va_size(va) == size) {
found = true;
break;
}
node = node->rb_right; list_for_each_entry(va, &free_vmap_area_list, list) {
} computed_size = compute_subtree_max_size(va);
} if (computed_size != va->subtree_max_size)
pr_emerg("tree is corrupted: %lu, %lu\n",
if (!found) { va_size(va), va->subtree_max_size);
va = rb_entry(n, struct vmap_area, rb_node);
pr_emerg("tree is corrupted: %lu, %lu\n",
va_size(va), va->subtree_max_size);
} }
augment_tree_propagate_check(n->rb_left);
augment_tree_propagate_check(n->rb_right);
} }
#endif #endif
...@@ -724,7 +698,7 @@ augment_tree_propagate_from(struct vmap_area *va) ...@@ -724,7 +698,7 @@ augment_tree_propagate_from(struct vmap_area *va)
} }
#if DEBUG_AUGMENT_PROPAGATE_CHECK #if DEBUG_AUGMENT_PROPAGATE_CHECK
augment_tree_propagate_check(free_vmap_area_root.rb_node); augment_tree_propagate_check();
#endif #endif
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment