[RFC PATCH 2/3] drivers: virtio_mem: use pageblock size as the minimum virtio_mem size.

[Zi Yan <zi.yan@sent.com>]

From: Zi Yan <ziy@nvidia.com>

alloc_contig_range() now only needs to be aligned to pageblock_order,
drop virtio_mem size requirement that it needs to be the max of
pageblock_order and MAX_ORDER.

Signed-off-by: Zi Yan <ziy@nvidia.com>
---
 drivers/virtio/virtio_mem.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index 0da0af251c73..a0a0994b42e2 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -2436,15 +2436,13 @@ static int virtio_mem_init_hotplug(struct virtio_mem *vm)
 				      VIRTIO_MEM_DEFAULT_OFFLINE_THRESHOLD);
 
 	/*
-	 * We want subblocks to span at least MAX_ORDER_NR_PAGES and
-	 * pageblock_nr_pages pages. This:
+	 * We want subblocks to span at least pageblock_nr_pages pages. This:
 	 * - Simplifies our page onlining code (virtio_mem_online_page_cb)
 	 *   and fake page onlining code (virtio_mem_fake_online).
 	 * - Is required for now for alloc_contig_range() to work reliably -
 	 *   it doesn't properly handle smaller granularity on ZONE_NORMAL.
 	 */
-	sb_size = max_t(uint64_t, MAX_ORDER_NR_PAGES,
-			pageblock_nr_pages) * PAGE_SIZE;
+	sb_size = pageblock_nr_pages * PAGE_SIZE;
 	sb_size = max_t(uint64_t, vm->device_block_size, sb_size);
 
 	if (sb_size < memory_block_size_bytes() && !force_bbm) {
-- 
2.33.0