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Tsirkin" To: Cindy Lu Cc: jasowang@redhat.com, michael.christie@oracle.com, sgarzare@redhat.com, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org Subject: Re: [PATCH v8 4/8] vhost: Introduce vhost_worker_ops in vhost_worker Message-ID: <20250407041540-mutt-send-email-mst@kernel.org> References: <20250328100359.1306072-1-lulu@redhat.com> <20250328100359.1306072-5-lulu@redhat.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250328100359.1306072-5-lulu@redhat.com> On Fri, Mar 28, 2025 at 06:02:48PM +0800, Cindy Lu wrote: > Abstract vhost worker operations (create/stop/wakeup) into an ops > structure to prepare for kthread mode support. > > Signed-off-by: Cindy Lu I worry about the overhead of indirect calls here. We have the wrappers, and only two options, why did you decide to add it like this, with ops? > --- > drivers/vhost/vhost.c | 63 ++++++++++++++++++++++++++++++------------- > drivers/vhost/vhost.h | 11 ++++++++ > 2 files changed, 56 insertions(+), 18 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index 20571bd6f7bd..c162ad772f8f 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -243,7 +243,7 @@ static void vhost_worker_queue(struct vhost_worker *worker, > * test_and_set_bit() implies a memory barrier. > */ > llist_add(&work->node, &worker->work_list); > - vhost_task_wake(worker->vtsk); > + worker->ops->wakeup(worker); > } > } > > @@ -706,7 +706,7 @@ static void vhost_worker_destroy(struct vhost_dev *dev, > > WARN_ON(!llist_empty(&worker->work_list)); > xa_erase(&dev->worker_xa, worker->id); > - vhost_task_stop(worker->vtsk); > + worker->ops->stop(worker); > kfree(worker); > } > > @@ -729,42 +729,69 @@ static void vhost_workers_free(struct vhost_dev *dev) > xa_destroy(&dev->worker_xa); > } > > +static void vhost_task_wakeup(struct vhost_worker *worker) > +{ > + return vhost_task_wake(worker->vtsk); > +} > + > +static void vhost_task_do_stop(struct vhost_worker *worker) > +{ > + return vhost_task_stop(worker->vtsk); > +} > + > +static int vhost_task_worker_create(struct vhost_worker *worker, > + struct vhost_dev *dev, const char *name) > +{ > + struct vhost_task *vtsk; > + u32 id; > + int ret; > + > + vtsk = vhost_task_create(vhost_run_work_list, vhost_worker_killed, > + worker, name); > + if (IS_ERR(vtsk)) > + return PTR_ERR(vtsk); > + > + worker->vtsk = vtsk; > + vhost_task_start(vtsk); > + ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL); > + if (ret < 0) { > + vhost_task_do_stop(worker); > + return ret; > + } > + worker->id = id; > + return 0; > +} > + > +static const struct vhost_worker_ops vhost_task_ops = { > + .create = vhost_task_worker_create, > + .stop = vhost_task_do_stop, > + .wakeup = vhost_task_wakeup, > +}; > + > static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev) > { > struct vhost_worker *worker; > - struct vhost_task *vtsk; > char name[TASK_COMM_LEN]; > int ret; > - u32 id; > + const struct vhost_worker_ops *ops = &vhost_task_ops; > > worker = kzalloc(sizeof(*worker), GFP_KERNEL_ACCOUNT); > if (!worker) > return NULL; > > worker->dev = dev; > + worker->ops = ops; > snprintf(name, sizeof(name), "vhost-%d", current->pid); > > - vtsk = vhost_task_create(vhost_run_work_list, vhost_worker_killed, > - worker, name); > - if (IS_ERR(vtsk)) > - goto free_worker; > - > mutex_init(&worker->mutex); > init_llist_head(&worker->work_list); > worker->kcov_handle = kcov_common_handle(); > - worker->vtsk = vtsk; > - > - vhost_task_start(vtsk); > - > - ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL); > + ret = ops->create(worker, dev, name); > if (ret < 0) > - goto stop_worker; > - worker->id = id; > + goto free_worker; > > return worker; > > -stop_worker: > - vhost_task_stop(vtsk); > free_worker: > kfree(worker); > return NULL; > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index 19bb94922a0e..98895e299efa 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -26,6 +26,16 @@ struct vhost_work { > unsigned long flags; > }; > > +struct vhost_worker; > +struct vhost_dev; > + > +struct vhost_worker_ops { > + int (*create)(struct vhost_worker *worker, struct vhost_dev *dev, > + const char *name); > + void (*stop)(struct vhost_worker *worker); > + void (*wakeup)(struct vhost_worker *worker); > +}; > + > struct vhost_worker { > struct vhost_task *vtsk; > struct vhost_dev *dev; > @@ -36,6 +46,7 @@ struct vhost_worker { > u32 id; > int attachment_cnt; > bool killed; > + const struct vhost_worker_ops *ops; > }; > > /* Poll a file (eventfd or socket) */ > -- > 2.45.0