* Peter Zijlstra [off-list ref] [210514 11:37]:

On Fri, May 14, 2021 at 05:32:15PM +0200, Peter Zijlstra wrote:

quoted

On Wed, Apr 28, 2021 at 03:36:02PM +0000, Liam Howlett wrote:

quoted

+static inline unsigned long mte_pivot(const struct maple_enode *mn,
+				 unsigned char piv)
+{
+	struct maple_node *node = mte_to_node(mn);
+
+	switch (mte_node_type(mn)) {
+	case maple_arange_64:
+		return node->ma64.pivot[piv];
+	case maple_range_64:
+	case maple_leaf_64:
+		return node->mr64.pivot[piv];
+	case maple_dense:
+	default:
+		return 0;
+	}
+}

Why is @piv 'unsigned char' ? Does that actually generate better code on
any architecture?

unsigned char is to match ma_state struct offset which is kept small
for cache efficiency.

At the same time; there's no bounds check.

I will add an assert.  Thanks.