On Thu, Jan 24, 2019 at 12:07:54PM +0800, Jason Wang wrote: > > Meanwhile, could you pls post data comparing this last patch with the > > below? This removes the speculation barrier replacing it with a > > (useless but at least more lightweight) data dependency. > > > SMAP off > > Your patch: 7.2MPPs > > vmap: 7.4Mpps OK so while we keep looking into vmap, why don't we merge something like the below? Seems quite straight forward ... > I don't test SMAP on, since it will be much slow for sure. > > Thanks > > > > > > Thanks! > > > > > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > > index bac939af8dbb..352ee7e14476 100644 > > --- a/drivers/vhost/vhost.c > > +++ b/drivers/vhost/vhost.c > > @@ -739,7 +739,7 @@ static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, > > int ret; > > if (!vq->iotlb) > > - return __copy_to_user(to, from, size); > > + return copy_to_user(to, from, size); > > else { > > /* This function should be called after iotlb > > * prefetch, which means we're sure that all vq > > @@ -752,7 +752,7 @@ static int vhost_copy_to_user(struct vhost_virtqueue *vq, void __user *to, > > VHOST_ADDR_USED); > > if (uaddr) > > - return __copy_to_user(uaddr, from, size); > > + return copy_to_user(uaddr, from, size); > > ret = translate_desc(vq, (u64)(uintptr_t)to, size, vq->iotlb_iov, > > ARRAY_SIZE(vq->iotlb_iov), > > @@ -774,7 +774,7 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, > > int ret; > > if (!vq->iotlb) > > - return __copy_from_user(to, from, size); > > + return copy_from_user(to, from, size); > > else { > > /* This function should be called after iotlb > > * prefetch, which means we're sure that vq > > @@ -787,7 +787,7 @@ static int vhost_copy_from_user(struct vhost_virtqueue *vq, void *to, > > struct iov_iter f; > > if (uaddr) > > - return __copy_from_user(to, uaddr, size); > > + return copy_from_user(to, uaddr, size); > > ret = translate_desc(vq, (u64)(uintptr_t)from, size, vq->iotlb_iov, > > ARRAY_SIZE(vq->iotlb_iov), > > @@ -855,13 +855,13 @@ static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, > > ({ \ > > int ret = -EFAULT; \ > > if (!vq->iotlb) { \ > > - ret = __put_user(x, ptr); \ > > + ret = put_user(x, ptr); \ > > } else { \ > > __typeof__(ptr) to = \ > > (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ > > sizeof(*ptr), VHOST_ADDR_USED); \ > > if (to != NULL) \ > > - ret = __put_user(x, to); \ > > + ret = put_user(x, to); \ > > else \ > > ret = -EFAULT; \ > > } \ > > @@ -872,14 +872,14 @@ static inline void __user *__vhost_get_user(struct vhost_virtqueue *vq, > > ({ \ > > int ret; \ > > if (!vq->iotlb) { \ > > - ret = __get_user(x, ptr); \ > > + ret = get_user(x, ptr); \ > > } else { \ > > __typeof__(ptr) from = \ > > (__typeof__(ptr)) __vhost_get_user(vq, ptr, \ > > sizeof(*ptr), \ > > type); \ > > if (from != NULL) \ > > - ret = __get_user(x, from); \ > > + ret = get_user(x, from); \ > > else \ > > ret = -EFAULT; \ > > } \