On Tue, Nov 5, 2024 at 5:36 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
> On Tue, Nov 5, 2024 at 3:27 PM Cindy Lu <lulu@xxxxxxxxxx> wrote:
> >
> > Restored the previous functions kthread_wakeup and kthread_stop.
> > Also add a new structure, vhost_task_fn. The function vhost_worker_create
> > Will initializes this structure based on the value of inherit_owner.
> >
> > Signed-off-by: Cindy Lu <lulu@xxxxxxxxxx>
> > ---
> > drivers/vhost/vhost.c | 71 ++++++++++++++++++++++++++++++++++++-------
> > drivers/vhost/vhost.h | 6 ++++
> > 2 files changed, 66 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> > index e40cef3a1fa5..603b146fccc1 100644
> > --- a/drivers/vhost/vhost.c
> > +++ b/drivers/vhost/vhost.c
> > @@ -741,43 +741,92 @@ static void vhost_workers_free(struct vhost_dev *dev)
> > xa_destroy(&dev->worker_xa);
> > }
> >
> > +static int vhost_task_wakeup_fn(void *vtsk)
> > +{
> > + vhost_task_wake((struct vhost_task *)vtsk);
> > + return 0;
> > +}
>
> Let's have a newline between two functions.
>
will fix this
> > +static int vhost_kthread_wakeup_fn(void *p)
> > +{
> > + return wake_up_process((struct task_struct *)p);
> > +}
> > +static int vhost_task_stop_fn(void *vtsk)
> > +{
> > + vhost_task_stop((struct vhost_task *)vtsk);
> > + return 0;
> > +}
> > +static int vhost_kthread_stop_fn(void *k)
> > +{
> > + return kthread_stop((struct task_struct *)k);
> > +}
> > +
> > static struct vhost_worker *vhost_worker_create(struct vhost_dev *dev)
> > {
> > struct vhost_worker *worker;
> > - struct vhost_task *vtsk;
> > + struct vhost_task *vtsk = NULL;
> > + struct task_struct *task = NULL;
> > char name[TASK_COMM_LEN];
> > int ret;
> > u32 id;
> >
> > + /* Allocate resources for the worker */
> > worker = kzalloc(sizeof(*worker), GFP_KERNEL_ACCOUNT);
> > if (!worker)
> > return NULL;
> >
> > + worker->fn = kzalloc(sizeof(struct vhost_task_fn), GFP_KERNEL_ACCOUNT);
> > + if (!worker->fn) {
> > + kfree(worker);
> > + return NULL;
> > + }
> > +
> > worker->dev = dev;
> > snprintf(name, sizeof(name), "vhost-%d", current->pid);
> >
> > - vtsk = vhost_task_create(vhost_run_work_list, vhost_worker_killed,
> > - worker, name);
> > - if (!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);
> > + if (dev->inherit_owner) {
> > + /* Create and start a vhost task */
> > + vtsk = vhost_task_create(vhost_run_work_list,
> > + vhost_worker_killed, worker, name);
> > + if (!vtsk)
> > + goto free_worker;
> > +
> > + worker->vtsk = vtsk;
> > + worker->fn->wakeup = vhost_task_wakeup_fn;
> > + worker->fn->stop = vhost_task_stop_fn;
> > +
> > + vhost_task_start(vtsk);
> > + } else {
> > + /* Create and start a kernel thread */
> > + task = kthread_create(vhost_run_work_kthread_list, worker,
> > + "vhost-%d", current->pid);
> > + if (IS_ERR(task)) {
> > + ret = PTR_ERR(task);
> > + goto free_worker;
> > + }
> > + worker->task = task;
> > + worker->fn->wakeup = vhost_kthread_wakeup_fn;
> > + worker->fn->stop = vhost_kthread_stop_fn;
> > +
> > + wake_up_process(task);
> > + /* Attach to the vhost cgroup */
> > + ret = vhost_attach_cgroups(dev);
> > + if (ret)
> > + goto stop_worker;
> > + }
> >
> > ret = xa_alloc(&dev->worker_xa, &id, worker, xa_limit_32b, GFP_KERNEL);
> > if (ret < 0)
> > goto stop_worker;
> > worker->id = id;
> > -
> > return worker;
> > -
> > stop_worker:
> > - vhost_task_stop(vtsk);
> > + worker->fn->stop(dev->inherit_owner ? (void *)vtsk : (void *)task);
> > free_worker:
> > + kfree(worker->fn);
> > kfree(worker);
> > return NULL;
> > }
> > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> > index c650c4506c70..ebababa4e340 100644
> > --- a/drivers/vhost/vhost.h
> > +++ b/drivers/vhost/vhost.h
> > @@ -25,8 +25,13 @@ struct vhost_work {
> > vhost_work_fn_t fn;
> > unsigned long flags;
> > };
> > +struct vhost_task_fn {
> > + int (*wakeup)(void *task);
>
> Let's have comments to explain the semantics of each operation.
>
sure, will fix this
> > + int (*stop)(void *task);
> > +};
>
> I think the goal is to reduce if/else, so while at this, let's
> introduce more ops. For example the create_worker one?
>
sure, will change this part
thanks
cindy
> >
> > struct vhost_worker {
> > + struct task_struct *task;
> > struct vhost_task *vtsk;
> > struct vhost_dev *dev;
> > /* Used to serialize device wide flushing with worker swapping. */
> > @@ -36,6 +41,7 @@ struct vhost_worker {
> > u32 id;
> > int attachment_cnt;
> > bool killed;
> > + struct vhost_task_fn *fn;
> > };
> >
> > /* Poll a file (eventfd or socket) */
> > --
> > 2.45.0
> >
>
> Thanks
>
