Commit 8087b177 authored May 17, 2019 by Uladzislau Rezki (Sony) Committed by Gerrit - the friendly Code Review server Jun 03, 2019

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>
Change-Id: I6cbf51a7614803a57fd9d067eca169635bcf4928
Git-Commit: bb850f4dae4abb18c5ee727bb2d6df9ca47ede49
Git-Repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>

parent 674e1206

mm/vmalloc.c

+48 −0

Original line number	Diff line number	Diff line
		@@ -324,6 +324,8 @@ EXPORT_SYMBOL(vmalloc_to_pfn);

		/* Global kva allocator */

		#define DEBUG_AUGMENT_PROPAGATE_CHECK 0

		#define VM_LAZY_FREE 0x02
		#define VM_VM_AREA 0x04

		@@ -545,6 +547,48 @@ 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
		@@ -594,6 +638,10 @@ 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