From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: [PATCH RFC] vhost: optimize interrupt enable/disable Date: Tue, 19 Jul 2011 18:04:34 +0300 Message-ID: <20110719150434.GA3413@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Jason Wang Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 --- It seems an obvious optimization so I queued this up already. drivers/vhost/vhost.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c16d225..c14c42b 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; -- 1.7.5.53.gc233e