From 347202dc04a110bdab8d4e1c38ceccd7758fe13e Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 12 Nov 2020 14:37:48 +0100 Subject: [PATCH] virtio-mem: more precise calculation in virtio_mem_mb_state_prepare_next_mb() We actually need one byte less (next_mb_id is exclusive, first_mb_id is inclusive). While at it, compact the code. Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20201112133815.13332-3-david@redhat.com Signed-off-by: Michael S. Tsirkin --- 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 a37fd73588da..dee46865bae2 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -257,10 +257,8 @@ static enum virtio_mem_mb_state virtio_mem_mb_get_state(struct virtio_mem *vm, */ static int virtio_mem_mb_state_prepare_next_mb(struct virtio_mem *vm) { - unsigned long old_bytes = vm->next_mb_id - vm->first_mb_id + 1; - unsigned long new_bytes = vm->next_mb_id - vm->first_mb_id + 2; - int old_pages = PFN_UP(old_bytes); - int new_pages = PFN_UP(new_bytes); + int old_pages = PFN_UP(vm->next_mb_id - vm->first_mb_id); + int new_pages = PFN_UP(vm->next_mb_id - vm->first_mb_id + 1); uint8_t *new_mb_state; if (vm->mb_state && old_pages == new_pages) -- 2.11.0