[PATCH 5/5] IB/rdmavt: use kzalloc() to allocate QPN-map pages

[Mike Rapoport (Microsoft)]

get_map_page() allocates bitmap pages using get_zeroed_page().

The bitmaps can be allocated with kmalloc() as there's nothing special
about them to go directly to the page allocator.

kmalloc() provides a better API that does not require ugly casts and
kfree() does not need to know the size of the freed object.

Performance difference between kmalloc() and __get_free_pages() is not
measurable as both allocators take an object/page from a per-CPU list for
fast path allocations.

For the slow path the performance is anyway determined by the amount of
reclaim involved rather than by what allocator is used.

Replace use of get_zeroed_page() with kzalloc() and free_page() with
kfree().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@xxxxxxxxxx
Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
---
 drivers/infiniband/sw/rdmavt/qp.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
index 70e7d08fdce6..c40cce69e945 100644
--- a/drivers/infiniband/sw/rdmavt/qp.c
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -263,7 +263,7 @@ static inline bool wss_exceeds_threshold(struct rvt_wss *wss)
 static void get_map_page(struct rvt_qpn_table *qpt,
 			 struct rvt_qpn_map *map)
 {
-	unsigned long page = get_zeroed_page(GFP_KERNEL);
+	void *page = kzalloc(PAGE_SIZE, GFP_KERNEL);
 
 	/*
 	 * Free the page if someone raced with us installing it.
@@ -271,9 +271,9 @@ static void get_map_page(struct rvt_qpn_table *qpt,
 
 	spin_lock(&qpt->lock);
 	if (map->page)
-		free_page(page);
+		kfree(page);
 	else
-		map->page = (void *)page;
+		map->page = page;
 	spin_unlock(&qpt->lock);
 }
 
@@ -343,7 +343,7 @@ static void free_qpn_table(struct rvt_qpn_table *qpt)
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(qpt->map); i++)
-		free_page((unsigned long)qpt->map[i].page);
+		kfree(qpt->map[i].page);
 }
 
 /**

-- 
2.53.0