On Thu, Aug 10, 2017 at 12:43:38PM -0400, Ted Unangst wrote:
> this moves writes into a thread. we need to do reads too, but the write side
> is much easier... could use a little more testing.
>
Reads ok to me, I'll try in my tree today.
-ml
>
> Index: virtio.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/vmd/virtio.c,v
> retrieving revision 1.49
> diff -u -p -r1.49 virtio.c
> --- virtio.c 30 May 2017 17:56:47 -0000 1.49
> +++ virtio.c 10 Aug 2017 16:41:59 -0000
> @@ -63,6 +63,7 @@ int nr_vioblk;
> #define VMMCI_F_SYNCRTC (1<<2)
>
> struct ioinfo {
> + TAILQ_ENTRY(ioinfo) next;
> uint8_t *buf;
> ssize_t len;
> off_t offset;
> @@ -70,6 +71,11 @@ struct ioinfo {
> int error;
> };
>
> +static pthread_t iothread;
> +static TAILQ_HEAD(, ioinfo) pending_ios;
> +static pthread_mutex_t iomtx;
> +static pthread_cond_t iocond;
> +
> const char *
> vioblk_cmd_name(uint32_t type)
> {
> @@ -415,6 +421,37 @@ vioblk_finish_write(struct ioinfo *info)
> return 0;
> }
>
> +static void *
> +vioblk_iowriter(void *v)
> +{
> + struct ioinfo *info;
> +
> + pthread_mutex_lock(&iomtx);
> + while (1) {
> + while ((info = TAILQ_FIRST(&pending_ios))) {
> + TAILQ_REMOVE(&pending_ios, info, next);
> + pthread_mutex_unlock(&iomtx);
> +
> + if (vioblk_finish_write(info))
> + log_warnx("wr vioblk: disk write error");
> +
> + vioblk_free_info(info);
> + pthread_mutex_lock(&iomtx);
> + }
> + pthread_cond_wait(&iocond, &iomtx);
> + }
> +}
> +
> +void
> +vioblk_writer_init(void)
> +{
> + TAILQ_INIT(&pending_ios);
> + pthread_mutex_init(&iomtx, NULL);
> + pthread_cond_init(&iocond, NULL);
> + pthread_create(&iothread, NULL, vioblk_iowriter, NULL);
> +
> +}
> +
> /*
> * XXX in various cases, ds should be set to VIRTIO_BLK_S_IOERR, if we can
> * XXX cant trust ring data from VM, be extra cautious.
> @@ -592,14 +629,10 @@ vioblk_notifyq(struct vioblk_dev *dev)
> goto out;
> }
>
> - if (vioblk_finish_write(info)) {
> - log_warnx("wr vioblk: disk write "
> - "error");
> - vioblk_free_info(info);
> - goto out;
> - }
> -
> - vioblk_free_info(info);
> + pthread_mutex_lock(&iomtx);
> + TAILQ_INSERT_TAIL(&pending_ios, info, next);
> + pthread_cond_signal(&iocond);
> + pthread_mutex_unlock(&iomtx);
>
> secbias += secdata_desc->len /
> VIRTIO_BLK_SECTOR_SIZE;
> Index: virtio.h
> ===================================================================
> RCS file: /cvs/src/usr.sbin/vmd/virtio.h,v
> retrieving revision 1.19
> diff -u -p -r1.19 virtio.h
> --- virtio.h 20 Jun 2017 01:59:12 -0000 1.19
> +++ virtio.h 10 Aug 2017 16:41:49 -0000
> @@ -178,6 +178,7 @@ int vioblk_restore(int, struct vm_create
> void vioblk_update_qs(struct vioblk_dev *);
> void vioblk_update_qa(struct vioblk_dev *);
> int vioblk_notifyq(struct vioblk_dev *);
> +void vioblk_writer_init(void);
>
> int virtio_net_io(int, uint16_t, uint32_t *, uint8_t *, void *, uint8_t);
> int vionet_dump(int);
> Index: vm.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/vmd/vm.c,v
> retrieving revision 1.22
> diff -u -p -r1.22 vm.c
> --- vm.c 15 Jul 2017 05:05:36 -0000 1.22
> +++ vm.c 10 Aug 2017 16:41:53 -0000
> @@ -1014,6 +1014,8 @@ run_vm(int *child_disks, int *child_taps
> return (ENOMEM);
> }
>
> + vioblk_writer_init();
> +
> log_debug("%s: initializing hardware for vm %s", __func__,
> vcp->vcp_name);
>
>
