Re: [PATCH 5/5] lib/interval_tree: Fast overlap detection

[Davidlohr Bueso]

On Tue, 30 May 2017, kbuild test robot wrote:

> Hi Davidlohr,
>
> [auto build test ERROR on next-20170529]
>
> url:    https://github.com/0day-ci/linux/commits/Davidlohr-Bueso/rbtree-Cache-leftmost-node-internally/20170530-101713
> config: x86_64-allmodconfig (attached as .config)
> compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
> reproduce:
>        # save the attached .config to linux build tree
>        make ARCH=x86_64
>
> All errors (new ones prefixed by >>):
>
>   include/linux/compiler.h:260:8: sparse: attribute 'no_sanitize_address': unknown attribute
>   drivers/infiniband/hw/hfi1/mmu_rb.c: In function 'hfi1_mmu_rb_insert':
> > > drivers/infiniband/hw/hfi1/mmu_rb.c:183:29: error: passing argument 2 of '__mmu_int_rb_insert' from incompatible pointer type [-Werror=incompatible-pointer-types]
>     __mmu_int_rb_insert(mnode, &handler->root);

Ah, I missed that interval tree user. The following fixes it along with
a bogus semicolon for rb_cached_first(). I can add this in v2 if we get
there.

Thanks,
Davidlohr

diff --git a/drivers/infiniband/hw/hfi1/mmu_rb.c b/drivers/infiniband/hw/hfi1/mmu_rb.c
index ccbf52c8ff6f..1835447dcd73 100644
--- a/drivers/infiniband/hw/hfi1/mmu_rb.c
+++ b/drivers/infiniband/hw/hfi1/mmu_rb.c
@@ -54,7 +54,7 @@

struct mmu_rb_handler {
	struct mmu_notifier mn;
-	struct rb_root root;
+	struct rb_root_cached root;
	void *ops_arg;
	spinlock_t lock;        /* protect the RB tree */
	struct mmu_rb_ops *ops;
@@ -111,7 +111,7 @@ int hfi1_mmu_rb_register(void *ops_arg, struct mm_struct *mm,
	if (!handlr)
		return -ENOMEM;

-	handlr->root = RB_ROOT;
+	handlr->root = RB_ROOT_CACHED;
	handlr->ops = ops;
	handlr->ops_arg = ops_arg;
	INIT_HLIST_NODE(&handlr->mn.hlist);
@@ -152,9 +152,9 @@ void hfi1_mmu_rb_unregister(struct mmu_rb_handler *handler)
	INIT_LIST_HEAD(&del_list);

	spin_lock_irqsave(&handler->lock, flags);
-	while ((node = rb_first(&handler->root))) {
+	while ((node = rb_first_cached(&handler->root))) {
		rbnode = rb_entry(node, struct mmu_rb_node, node);
-		rb_erase(node, &handler->root);
+		rb_erase_cached(node, &handler->root);
		/* move from LRU list to delete list */
		list_move(&rbnode->list, &del_list);
	}
@@ -305,7 +305,7 @@ static void mmu_notifier_mem_invalidate(struct mmu_notifier *mn,
{
	struct mmu_rb_handler *handler =
		container_of(mn, struct mmu_rb_handler, mn);
-	struct rb_root *root = &handler->root;
+	struct rb_root_cached *root = &handler->root;
	struct mmu_rb_node *node, *ptr = NULL;
	unsigned long flags;
	bool added = false;
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index eb4544811cfd..71c9ee585454 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -78,7 +78,7 @@ extern void rb_insert_color_cached(struct rb_node *,
				   struct rb_root_cached *, bool);
extern void rb_erase_cached(struct rb_node *node, struct rb_root_cached *);
/* Same as rb_first(), but O(1) */
-#define rb_first_cached(root) (root)->rb_leftmost;
+#define rb_first_cached(root) (root)->rb_leftmost

/* Postorder iteration - always visit the parent after its children */
extern struct rb_node *rb_first_postorder(const struct rb_root *);