Jason Wang
2022-Dec-16 05:35 UTC
[PATCH v2 08/11] vduse: Add sysfs interface for irq callback affinity
On Mon, Dec 5, 2022 at 5:03 PM Xie Yongji <xieyongji at bytedance.com> wrote:> > Add sysfs interface for each vduse virtqueue to > show the affinity and effective affinity for irq > callback. > > And we can also use this interface to change the > effective affinity which must be a subset of the > irq callback affinity mask for the virtqueue. This > might be useful for performance tuning when the irq > callback affinity mask contains more than one CPU. > > Signed-off-by: Xie Yongji <xieyongji at bytedance.com> > --- > drivers/vdpa/vdpa_user/vduse_dev.c | 148 ++++++++++++++++++++++++++--- > 1 file changed, 137 insertions(+), 11 deletions(-) > > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c > index 6507a78abc9d..c65f84100e30 100644 > --- a/drivers/vdpa/vdpa_user/vduse_dev.c > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c > @@ -61,6 +61,7 @@ struct vduse_virtqueue { > int irq_effective_cpu; > struct cpumask irq_affinity; > spinlock_t irq_affinity_lock; > + struct kobject kobj; > }; > > struct vduse_dev; > @@ -1419,6 +1420,120 @@ static const struct file_operations vduse_dev_fops = { > .llseek = noop_llseek, > }; > > +static ssize_t irq_cb_affinity_show(struct vduse_virtqueue *vq, char *buf) > +{ > + return sprintf(buf, "%*pb\n", cpumask_pr_args(&vq->irq_affinity)); > +} > + > +static ssize_t irq_cb_effective_affinity_show(struct vduse_virtqueue *vq, > + char *buf) > +{ > + struct cpumask all_mask = CPU_MASK_ALL; > + const struct cpumask *mask = &all_mask; > + > + if (vq->irq_effective_cpu != -1) > + mask = get_cpu_mask(vq->irq_effective_cpu);Shouldn't this be vq->irq_affinity?> + > + return sprintf(buf, "%*pb\n", cpumask_pr_args(mask)); > +} > + > +static ssize_t irq_cb_effective_affinity_store(struct vduse_virtqueue *vq, > + const char *buf, size_t count) > +{ > + cpumask_var_t new_value; > + int ret; > + > + if (!zalloc_cpumask_var(&new_value, GFP_KERNEL)) > + return -ENOMEM; > + > + ret = cpumask_parse(buf, new_value); > + if (ret) > + goto free_mask; > + > + ret = -EINVAL; > + if (!cpumask_intersects(new_value, &vq->irq_affinity)) > + goto free_mask; > + > + spin_lock(&vq->irq_affinity_lock); > + > + if (vq->irq_effective_cpu != -1) > + per_cpu(vduse_allocated_irq, vq->irq_effective_cpu) -= 1; > + > + vq->irq_effective_cpu = cpumask_first(new_value);Does this mean except for the first cpu, the rest of the mask is unused? Thanks> + per_cpu(vduse_allocated_irq, vq->irq_effective_cpu) += 1; > + > + spin_unlock(&vq->irq_affinity_lock); > + ret = count; > + > +free_mask: > + free_cpumask_var(new_value); > + return ret; > +} > + > +struct vq_sysfs_entry { > + struct attribute attr; > + ssize_t (*show)(struct vduse_virtqueue *vq, char *buf); > + ssize_t (*store)(struct vduse_virtqueue *vq, const char *buf, > + size_t count); > +}; > + > +static struct vq_sysfs_entry irq_cb_affinity_attr = __ATTR_RO(irq_cb_affinity); > +static struct vq_sysfs_entry irq_cb_effective_affinity_attr > + __ATTR_RW(irq_cb_effective_affinity); > + > +static struct attribute *vq_attrs[] = { > + &irq_cb_affinity_attr.attr, > + &irq_cb_effective_affinity_attr.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(vq); > + > +static ssize_t vq_attr_show(struct kobject *kobj, struct attribute *attr, > + char *buf) > +{ > + struct vduse_virtqueue *vq = container_of(kobj, > + struct vduse_virtqueue, kobj); > + struct vq_sysfs_entry *entry = container_of(attr, > + struct vq_sysfs_entry, attr); > + > + if (!entry->show) > + return -EIO; > + > + return entry->show(vq, buf); > +} > + > +static ssize_t vq_attr_store(struct kobject *kobj, struct attribute *attr, > + const char *buf, size_t count) > +{ > + struct vduse_virtqueue *vq = container_of(kobj, > + struct vduse_virtqueue, kobj); > + struct vq_sysfs_entry *entry = container_of(attr, > + struct vq_sysfs_entry, attr); > + > + if (!entry->store) > + return -EIO; > + > + return entry->store(vq, buf, count); > +} > + > +static const struct sysfs_ops vq_sysfs_ops = { > + .show = vq_attr_show, > + .store = vq_attr_store, > +}; > + > +static void vq_release(struct kobject *kobj) > +{ > + struct vduse_virtqueue *vq = container_of(kobj, > + struct vduse_virtqueue, kobj); > + kfree(vq); > +} > + > +static struct kobj_type vq_type = { > + .release = vq_release, > + .sysfs_ops = &vq_sysfs_ops, > + .default_groups = vq_groups, > +}; > + > static void vduse_dev_deinit_vqs(struct vduse_dev *dev) > { > int i; > @@ -1427,13 +1542,13 @@ static void vduse_dev_deinit_vqs(struct vduse_dev *dev) > return; > > for (i = 0; i < dev->vq_num; i++) > - kfree(dev->vqs[i]); > + kobject_put(&dev->vqs[i]->kobj); > kfree(dev->vqs); > } > > static int vduse_dev_init_vqs(struct vduse_dev *dev, u32 vq_align, u32 vq_num) > { > - int i; > + int ret, i; > > dev->vq_align = vq_align; > dev->vq_num = vq_num; > @@ -1443,8 +1558,10 @@ static int vduse_dev_init_vqs(struct vduse_dev *dev, u32 vq_align, u32 vq_num) > > for (i = 0; i < vq_num; i++) { > dev->vqs[i] = kzalloc(sizeof(*dev->vqs[i]), GFP_KERNEL); > - if (!dev->vqs[i]) > + if (!dev->vqs[i]) { > + ret = -ENOMEM; > goto err; > + } > > dev->vqs[i]->index = i; > dev->vqs[i]->irq_effective_cpu = -1; > @@ -1454,15 +1571,23 @@ static int vduse_dev_init_vqs(struct vduse_dev *dev, u32 vq_align, u32 vq_num) > spin_lock_init(&dev->vqs[i]->irq_lock); > spin_lock_init(&dev->vqs[i]->irq_affinity_lock); > cpumask_setall(&dev->vqs[i]->irq_affinity); > + > + kobject_init(&dev->vqs[i]->kobj, &vq_type); > + ret = kobject_add(&dev->vqs[i]->kobj, > + &dev->dev->kobj, "vq%d", i); > + if (ret) { > + kfree(dev->vqs[i]); > + goto err; > + } > } > > return 0; > err: > while (i--) > - kfree(dev->vqs[i]); > + kobject_put(&dev->vqs[i]->kobj); > kfree(dev->vqs); > dev->vqs = NULL; > - return -ENOMEM; > + return ret; > } > > static struct vduse_dev *vduse_dev_create(void) > @@ -1637,10 +1762,6 @@ static int vduse_create_dev(struct vduse_dev_config *config, > dev->config = config_buf; > dev->config_size = config->config_size; > > - ret = vduse_dev_init_vqs(dev, config->vq_align, config->vq_num); > - if (ret) > - goto err_vqs; > - > ret = idr_alloc(&vduse_idr, dev, 1, VDUSE_DEV_MAX, GFP_KERNEL); > if (ret < 0) > goto err_idr; > @@ -1654,14 +1775,19 @@ static int vduse_create_dev(struct vduse_dev_config *config, > ret = PTR_ERR(dev->dev); > goto err_dev; > } > + > + ret = vduse_dev_init_vqs(dev, config->vq_align, config->vq_num); > + if (ret) > + goto err_vqs; > + > __module_get(THIS_MODULE); > > return 0; > +err_vqs: > + device_destroy(vduse_class, MKDEV(MAJOR(vduse_major), dev->minor)); > err_dev: > idr_remove(&vduse_idr, dev->minor); > err_idr: > - vduse_dev_deinit_vqs(dev); > -err_vqs: > vduse_domain_destroy(dev->domain); > err_domain: > kfree(dev->name); > -- > 2.20.1 >