hv_balloon: simplify math in alloc_balloon_pages()

'alloc_unit' in alloc_balloon_pages() is either '512' for 2M allocations or
'1' for 4k allocations. So

1 << get_order(alloc_unit << PAGE_SHIFT)

equals to 'alloc_unit' and the for loop basically sets all them offline.
Simplify the math to improve the readability.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201202161245.2406143-2-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index eb56e09ae15f3999478b0e75f601836c92ad175a..da3b6bd2367c8916b07fceae85ce70ea21c06311 100644 (file)
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -1238,7 +1238,7 @@ static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm,
                        split_page(pg, get_order(alloc_unit << PAGE_SHIFT));
 
                /* mark all pages offline */
-               for (j = 0; j < (1 << get_order(alloc_unit << PAGE_SHIFT)); j++)
+               for (j = 0; j < alloc_unit; j++)
                        __SetPageOffline(pg + j);
 
                bl_resp->range_count++;