Clean up relay_alloc_page_array() slightly by using vzalloc rather than vmalloc and memset

We can optimize kernel/relay.c::relay_alloc_page_array() slightly by
using vzalloc.  The patch makes these changes:

 - use vzalloc instead of vmalloc+memset.
 - remove redundant local variable 'array'.
 - declare local 'pa_size' as const.

Cuts down nicely on both source and object-code size.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 11 deletions

diff --git a/kernel/relay.c b/kernel/relay.c
index c7cf397fb929..859ea5a9605f 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -70,17 +70,10 @@ static const struct vm_operations_struct relay_file_mmap_ops = {
  */
 static struct page **relay_alloc_page_array(unsigned int n_pages)
 {
-        struct page **array;
-        size_t pa_size = n_pages * sizeof(struct page *);
-
-        if (pa_size > PAGE_SIZE) {
-                array = vmalloc(pa_size);
-                if (array)
-                        memset(array, 0, pa_size);
-        } else {
-                array = kzalloc(pa_size, GFP_KERNEL);
-        }
-        return array;
+        const size_t pa_size = n_pages * sizeof(struct page *);
+        if (pa_size > PAGE_SIZE)
+                return vzalloc(pa_size);
+        return kzalloc(pa_size, GFP_KERNEL);
 }
 
 /*