From fcc042a2806064ffcaed7a0c5cb710eca0e99108 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Sun, 6 Mar 2011 13:33:49 +0200 Subject: [PATCH] vhost: copy_from_user -> __copy_from_user copy_from_user is pretty high on perf top profile, replacing it with __copy_from_user helps. It's also safe because we do access_ok checks during setup. Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index b0cc7f8ca4de..2ab291241635 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1171,7 +1171,7 @@ int vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq, i, vq->num, head); return -EINVAL; } - ret = copy_from_user(&desc, vq->desc + i, sizeof desc); + ret = __copy_from_user(&desc, vq->desc + i, sizeof desc); if (unlikely(ret)) { vq_err(vq, "Failed to get descriptor: idx %d addr %p\n", i, vq->desc + i); -- 2.39.5