From: Michael S. Tsirkin <mst@redhat.com>
Date: Tue, 19 Jul 2011 14:15:43 +0000 (+0300)
Subject: vhost: optimize interrupt enable/disable
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b834226b04d6fb51178a64e98872856986c71474;p=linux-beck.git

vhost: optimize interrupt enable/disable

As we now only update used ring after enabling
the backend, we can write flags with __put_user:
as that's done on data path, it matters.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index c16d22545868..c14c42b95ab8 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -998,7 +998,7 @@ int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
 static int vhost_update_used_flags(struct vhost_virtqueue *vq)
 {
 	void __user *used;
-	if (put_user(vq->used_flags, &vq->used->flags) < 0)
+	if (__put_user(vq->used_flags, &vq->used->flags) < 0)
 		return -EFAULT;
 	if (unlikely(vq->log_used)) {
 		/* Make sure the flag is seen before log. */
@@ -1016,7 +1016,7 @@ static int vhost_update_used_flags(struct vhost_virtqueue *vq)
 
 static int vhost_update_avail_event(struct vhost_virtqueue *vq, u16 avail_event)
 {
-	if (put_user(vq->avail_idx, vhost_avail_event(vq)))
+	if (__put_user(vq->avail_idx, vhost_avail_event(vq)))
 		return -EFAULT;
 	if (unlikely(vq->log_used)) {
 		void __user *used;