From bb850f4dae4abb18c5ee727bb2d6df9ca47ede49 Mon Sep 17 00:00:00 2001
From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Date: Fri, 17 May 2019 14:31:34 -0700
Subject: [PATCH] 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.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Roman 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/vmalloc.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index f8f61ff3235bc..aac34c2a410b3 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -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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