We want to support several vhost workers. The first step is to rework vhost to use array of workers rather than single pointer. Update creation and cleanup routines.
https://jira.sw.ru/browse/PSBM-139414 Signed-off-by: Andrey Zhadchenko <andrey.zhadche...@virtuozzo.com> --- v3: set vq->worker to NULL in vhost_vq_reset() drivers/vhost/vhost.c | 76 +++++++++++++++++++++++++++++++------------ drivers/vhost/vhost.h | 10 +++++- 2 files changed, 64 insertions(+), 22 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index a0bfc77c6a43..321967322285 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -231,11 +231,24 @@ void vhost_poll_stop(struct vhost_poll *poll) } EXPORT_SYMBOL_GPL(vhost_poll_stop); +static void vhost_work_queue_at_worker(struct vhost_worker *w, + struct vhost_work *work) +{ + if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) { + /* We can only add the work to the list after we're + * sure it was not in the list. + * test_and_set_bit() implies a memory barrier. + */ + llist_add(&work->node, &w->work_list); + wake_up_process(w->worker); + } +} + void vhost_work_dev_flush(struct vhost_dev *dev) { struct vhost_flush_struct flush; - if (dev->worker) { + if (dev->workers[0].worker) { init_completion(&flush.wait_event); vhost_work_init(&flush.work, vhost_flush_work); @@ -255,17 +268,12 @@ EXPORT_SYMBOL_GPL(vhost_poll_flush); void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work) { - if (!dev->worker) + struct vhost_worker *w = &dev->workers[0]; + + if (!w->worker) return; - if (!test_and_set_bit(VHOST_WORK_QUEUED, &work->flags)) { - /* We can only add the work to the list after we're - * sure it was not in the list. - * test_and_set_bit() implies a memory barrier. - */ - llist_add(&work->node, &dev->work_list); - wake_up_process(dev->worker); - } + vhost_work_queue_at_worker(w, work); } EXPORT_SYMBOL_GPL(vhost_work_queue); @@ -339,11 +347,32 @@ static void vhost_vq_reset(struct vhost_dev *dev, vq->iotlb = NULL; vhost_vring_call_reset(&vq->call_ctx); __vhost_vq_meta_reset(vq); + vq->worker = NULL; +} + +static void vhost_worker_reset(struct vhost_worker *w) +{ + init_llist_head(&w->work_list); + w->worker = NULL; +} + +void vhost_cleanup_workers(struct vhost_dev *dev) +{ + int i; + + for (i = 0; i < dev->nworkers; ++i) { + WARN_ON(!llist_empty(&dev->workers[i].work_list)); + kthread_stop(dev->workers[i].worker); + vhost_worker_reset(&dev->workers[i]); + } + + dev->nworkers = 0; } static int vhost_worker(void *data) { - struct vhost_dev *dev = data; + struct vhost_worker *w = data; + struct vhost_dev *dev = w->dev; struct vhost_work *work, *work_next; struct llist_node *node; @@ -358,7 +387,7 @@ static int vhost_worker(void *data) break; } - node = llist_del_all(&dev->work_list); + node = llist_del_all(&w->work_list); if (!node) schedule(); @@ -481,7 +510,6 @@ void vhost_dev_init(struct vhost_dev *dev, dev->umem = NULL; dev->iotlb = NULL; dev->mm = NULL; - dev->worker = NULL; dev->iov_limit = iov_limit; dev->weight = weight; dev->byte_weight = byte_weight; @@ -493,6 +521,11 @@ void vhost_dev_init(struct vhost_dev *dev, INIT_LIST_HEAD(&dev->pending_list); spin_lock_init(&dev->iotlb_lock); + dev->nworkers = 0; + for (i = 0; i < VHOST_MAX_WORKERS; ++i) { + dev->workers[i].dev = dev; + vhost_worker_reset(&dev->workers[i]); + } for (i = 0; i < dev->nvqs; ++i) { vq = dev->vqs[i]; @@ -602,7 +635,8 @@ long vhost_dev_set_owner(struct vhost_dev *dev) goto err_worker; } - dev->worker = worker; + dev->workers[0].worker = worker; + dev->nworkers = 1; wake_up_process(worker); /* avoid contributing to loadavg */ err = vhost_attach_cgroups(dev); @@ -616,9 +650,10 @@ long vhost_dev_set_owner(struct vhost_dev *dev) return 0; err_cgroup: - if (dev->worker) { - kthread_stop(dev->worker); - dev->worker = NULL; + dev->nworkers = 0; + if (dev->workers[0].worker) { + kthread_stop(dev->workers[0].worker); + dev->workers[0].worker = NULL; } err_worker: vhost_detach_mm(dev); @@ -701,6 +736,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev) eventfd_ctx_put(dev->vqs[i]->call_ctx.ctx); vhost_vq_reset(dev, dev->vqs[i]); } + vhost_dev_free_iovecs(dev); if (dev->log_ctx) eventfd_ctx_put(dev->log_ctx); @@ -712,10 +748,8 @@ void vhost_dev_cleanup(struct vhost_dev *dev) dev->iotlb = NULL; vhost_clear_msg(dev); wake_up_interruptible_poll(&dev->wait, EPOLLIN | EPOLLRDNORM); - WARN_ON(!llist_empty(&dev->work_list)); - if (dev->worker) { - kthread_stop(dev->worker); - dev->worker = NULL; + if (dev->use_worker) { + vhost_cleanup_workers(dev); dev->kcov_handle = 0; } vhost_detach_mm(dev); diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 638bb640d6b4..634ea828cbba 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -25,6 +25,13 @@ struct vhost_work { unsigned long flags; }; +#define VHOST_MAX_WORKERS 4 +struct vhost_worker { + struct task_struct *worker; + struct llist_head work_list; + struct vhost_dev *dev; +}; + /* Poll a file (eventfd or socket) */ /* Note: there's nothing vhost specific about this structure. */ struct vhost_poll { @@ -149,7 +156,8 @@ struct vhost_dev { int nvqs; struct eventfd_ctx *log_ctx; struct llist_head work_list; - struct task_struct *worker; + struct vhost_worker workers[VHOST_MAX_WORKERS]; + int nworkers; struct vhost_iotlb *umem; struct vhost_iotlb *iotlb; spinlock_t iotlb_lock; -- 2.31.1 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
