Commit bb850f4d authored by Uladzislau Rezki (Sony)'s avatar Uladzislau Rezki (Sony) Committed by Linus Torvalds

mm/vmap: add DEBUG_AUGMENT_PROPAGATE_CHECK macro

This macro adds some debug code to check that the augment tree is
maintained correctly, meaning that every node contains valid
subtree_max_size value.

By default this option is set to 0 and not active.  It requires
recompilation of the kernel to activate it.  Set to 1, compile the
kernel.

[urezki@gmail.com: v4]
  Link: http://lkml.kernel.org/r/20190406183508.25273-3-urezki@gmail.com
Link: http://lkml.kernel.org/r/20190402162531.10888-3-urezki@gmail.comSigned-off-by: default avatarUladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: default avatarRoman Gushchin <guro@fb.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 68ad4a33
......@@ -325,6 +325,8 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
/*** Global kva allocator ***/
#define DEBUG_AUGMENT_PROPAGATE_CHECK 0
#define VM_LAZY_FREE 0x02
#define VM_VM_AREA 0x04
......@@ -539,6 +541,48 @@ unlink_va(struct vmap_area *va, struct rb_root *root)
}
}
#if DEBUG_AUGMENT_PROPAGATE_CHECK
static void
augment_tree_propagate_check(struct rb_node *n)
{
struct vmap_area *va;
struct rb_node *node;
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;
}
}
if (!found) {
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
/*
* This function populates subtree_max_size from bottom to upper
* levels starting from VA point. The propagation must be done
......@@ -588,6 +632,10 @@ augment_tree_propagate_from(struct vmap_area *va)
va->subtree_max_size = new_va_sub_max_size;
node = rb_parent(&va->rb_node);
}
#if DEBUG_AUGMENT_PROPAGATE_CHECK
augment_tree_propagate_check(free_vmap_area_root.rb_node);
#endif
}
static void
......
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