On Fri, Aug 18, 2017 at 03:39:27PM +0800, Wei Wang wrote: > On 08/18/2017 10:22 AM, Michael S. Tsirkin wrote: > > +static void send_balloon_page_sg(struct virtio_balloon *vb, > > + struct virtqueue *vq, > > + void *addr, > > + uint32_t size) > > +{ > > + unsigned int len; > > + int ret; > > + > > + do { > > + ret = add_one_sg(vq, addr, size); > > + virtqueue_kick(vq); > > + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > > + /* > > + * It is uncommon to see the vq is full, because the sg is sent > > + * one by one and the device is able to handle it in time. But > > + * if that happens, we go back to retry after an entry gets > > + * released. > > + */ > > Why send one by one though? Why not batch some s/gs and wait for all > > of them to be completed? If memory if fragmented, waiting every time is > > worse than what we have now (VIRTIO_BALLOON_ARRAY_PFNS_MAX at a time). > > > > OK, I'll do batching in some fashion. > > > Best, > Wei > > btw you need to address the build errors that kbot has found. -- MST