On 10.03.20 12:19, Michael S. Tsirkin wrote: > On Tue, Mar 10, 2020 at 12:12:50PM +0100, David Hildenbrand wrote: >>>> static void virtio_balloon_unregister_shrinker(struct virtio_balloon *vb) >>>> @@ -971,7 +950,22 @@ static int virtballoon_probe(struct virtio_device *vdev) >>>> VIRTIO_BALLOON_CMD_ID_STOP); >>>> spin_lock_init(&vb->free_page_list_lock); >>>> INIT_LIST_HEAD(&vb->free_page_list); >>>> + /* >>>> + * We're allowed to reuse any free pages, even if they are >>>> + * still to be processed by the host. >>>> + */ >>>> + err = virtio_balloon_register_shrinker(vb); >>>> + if (err) >>>> + goto out_del_balloon_wq; >>>> } >>>> + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) { >>>> + vb->oom_nb.notifier_call = virtio_balloon_oom_notify; >>>> + vb->oom_nb.priority = VIRTIO_BALLOON_OOM_NOTIFY_PRIORITY; >>>> + err = register_oom_notifier(&vb->oom_nb); >>>> + if (err < 0) >>>> + goto out_unregister_shrinker; >>>> + } >>>> + >>> >>> >>> Let's decide whether we want an empty line after }, or not, and stick to >>> it. I prefer an empty line but no biggie as long as we are consistent. >> >> Can add one. >> >>> >>>> if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { >>>> /* Start with poison val of 0 representing general init */ >>>> __u32 poison_val = 0; >>>> @@ -986,15 +980,6 @@ static int virtballoon_probe(struct virtio_device *vdev) >>>> virtio_cwrite(vb->vdev, struct virtio_balloon_config, >>>> poison_val, &poison_val); >>>> } >>>> - /* >>>> - * We continue to use VIRTIO_BALLOON_F_DEFLATE_ON_OOM to decide if a >>>> - * shrinker needs to be registered to relieve memory pressure. >>>> - */ >>>> - if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) { >>>> - err = virtio_balloon_register_shrinker(vb); >>>> - if (err) >>>> - goto out_del_balloon_wq; >>>> - } >>>> >>>> vb->pr_dev_info.report = virtballoon_free_page_report; >>>> if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) { >>>> @@ -1003,12 +988,12 @@ static int virtballoon_probe(struct virtio_device *vdev) >>>> capacity = virtqueue_get_vring_size(vb->reporting_vq); >>>> if (capacity < PAGE_REPORTING_CAPACITY) { >>>> err = -ENOSPC; >>>> - goto out_unregister_shrinker; >>>> + goto out_unregister_oom; >>>> } >>>> >>>> err = page_reporting_register(&vb->pr_dev_info); >>>> if (err) >>>> - goto out_unregister_shrinker; >>>> + goto out_unregister_oom; >>>> } >>>> >>>> virtio_device_ready(vdev); >>>> @@ -1017,8 +1002,11 @@ static int virtballoon_probe(struct virtio_device *vdev) >>>> virtballoon_changed(vdev); >>>> return 0; >>>> >>>> +out_unregister_oom: >>>> + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) >>>> + unregister_oom_notifier(&vb->oom_nb); >>>> out_unregister_shrinker: >>>> - if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) >>>> + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) >>>> virtio_balloon_unregister_shrinker(vb); >>> >>> >>> What's with vdev versus vb->vdev here? >>> I suggest we keep using vb->vdev to make the patch minimal if we can. >>> Same elsewhere. >> >> As we touch this line either way, does it really make a difference? No >> strong opinion. Can just do a vb->vdev and clean this up globally later. >> > > Let's just be consistent. I guess that means keep using vb->vdev > everywhere. It's already really inconsistent, so I'll use vb->vdev in this patch and cleanup the other users later. -- Thanks, David / dhildenb _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization