From 63b9b80e9f5b2c463d98d6e550e0d0e3ace66033 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Tue, 19 Nov 2019 05:25:24 -0500 Subject: virtio_balloon: divide/multiply instead of shifts We managed to get confused about the shift direction at least once. Let's switch to division/multiplcation instead. Add a number of pages macro for this purpose. We still keep the order macro around too since this is what alloc/free pages want. Signed-off-by: Michael S. Tsirkin Reviewed-by: Wei Wang Reviewed-by: David Hildenbrand --- drivers/virtio/virtio_balloon.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'drivers/virtio/virtio_balloon.c') diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 23119b3a71bd..93f995f6cf36 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -36,6 +36,7 @@ /* The size of a free page block in bytes */ #define VIRTIO_BALLOON_HINT_BLOCK_BYTES \ (1 << (VIRTIO_BALLOON_HINT_BLOCK_ORDER + PAGE_SHIFT)) +#define VIRTIO_BALLOON_HINT_BLOCK_PAGES (1 << VIRTIO_BALLOON_HINT_BLOCK_ORDER) #ifdef CONFIG_BALLOON_COMPACTION static struct vfsmount *balloon_mnt; @@ -776,11 +777,11 @@ static unsigned long shrink_free_pages(struct virtio_balloon *vb, unsigned long blocks_to_free, blocks_freed; pages_to_free = round_up(pages_to_free, - 1 << VIRTIO_BALLOON_HINT_BLOCK_ORDER); - blocks_to_free = pages_to_free >> VIRTIO_BALLOON_HINT_BLOCK_ORDER; + VIRTIO_BALLOON_HINT_BLOCK_PAGES); + blocks_to_free = pages_to_free / VIRTIO_BALLOON_HINT_BLOCK_PAGES; blocks_freed = return_free_pages_to_mm(vb, blocks_to_free); - return blocks_freed << VIRTIO_BALLOON_HINT_BLOCK_ORDER; + return blocks_freed * VIRTIO_BALLOON_HINT_BLOCK_PAGES; } static unsigned long leak_balloon_pages(struct virtio_balloon *vb, @@ -837,7 +838,7 @@ static unsigned long virtio_balloon_shrinker_count(struct shrinker *shrinker, unsigned long count; count = vb->num_pages / VIRTIO_BALLOON_PAGES_PER_PAGE; - count += vb->num_free_page_blocks << VIRTIO_BALLOON_HINT_BLOCK_ORDER; + count += vb->num_free_page_blocks * VIRTIO_BALLOON_HINT_BLOCK_PAGES; return count; } -- cgit v1.2.3