On 12/1/21 15:29, Liam Howlett wrote:

From: "Liam R. Howlett" <redacted>

The maple tree code was added to find the unmapped area in a previous
commit and was checked against what the rbtree returned, but the actual
result was never used.  Start using the maple tree implementation and
remove the rbtree code.

Nice cleanup. But...

Add kernel documentation comment for these functions.

Signed-off-by: Liam R. Howlett <redacted>

 
 	/* Adjust search length to account for worst case alignment overhead */
 	length = info->length + info->align_mask;
 	if (length < info->length)
 		return -ENOMEM;
 
-	rcu_read_lock();
-	mas_empty_area_rev(&mas, info->low_limit, info->high_limit - 1,
-			   length);
-	rcu_read_unlock();

Why is RCU locking being removed as part of this? Ditton in
unmapped_area_topdown()