Support virtio-fs multiple virtqueues and distribute requests across the multiqueue complex automatically based on the IRQ affinity. This commit is based on Connor's patch in the virtio-fs mailing-list, and additionally intergates cpu-to-vq map into struct virtio_fs so that this virtio-fs multi-queue feature can fit into multiple virtio-fs mounts. Link: https://www.mail-archive.com/virtio-fs@xxxxxxxxxx/msg03320.html Suggested-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx> Cc: Connor Kuehl <ckuehl@xxxxxxxxxx> Signed-off-by: Jiachen Zhang <zhangjiachen.jaycee@xxxxxxxxxxxxx> --- fs/fuse/virtio_fs.c | 37 +++++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 8 deletions(-) diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index 4d8d4f16c727..410968dede0c 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -32,8 +32,9 @@ static DEFINE_MUTEX(virtio_fs_mutex); static LIST_HEAD(virtio_fs_instances); enum { - VQ_HIPRIO, - VQ_REQUEST + VQ_HIPRIO = 0, + /* TODO add VQ_NOTIFICATION according to the virtio 1.2 spec. */ + VQ_REQUEST = 1, }; #define VQ_NAME_LEN 24 @@ -59,6 +60,7 @@ struct virtio_fs { struct list_head list; /* on virtio_fs_instances */ char *tag; struct virtio_fs_vq *vqs; + struct virtio_fs_vq * __percpu *vq_proxy; unsigned int nvqs; /* number of virtqueues */ unsigned int num_request_queues; /* number of request queues */ struct dax_device *dax_dev; @@ -686,6 +688,7 @@ static int virtio_fs_setup_vqs(struct virtio_device *vdev, struct virtqueue **vqs; vq_callback_t **callbacks; const char **names; + struct irq_affinity desc = { .pre_vectors = 1, .nr_sets = 1, }; unsigned int i; int ret = 0; @@ -694,11 +697,16 @@ static int virtio_fs_setup_vqs(struct virtio_device *vdev, if (fs->num_request_queues == 0) return -EINVAL; + fs->num_request_queues = min_t(unsigned int, nr_cpu_ids, + fs->num_request_queues); + fs->nvqs = VQ_REQUEST + fs->num_request_queues; fs->vqs = kcalloc(fs->nvqs, sizeof(fs->vqs[VQ_HIPRIO]), GFP_KERNEL); if (!fs->vqs) return -ENOMEM; + pr_debug("virtio-fs: number of vqs: %d\n", fs->nvqs); + vqs = kmalloc_array(fs->nvqs, sizeof(vqs[VQ_HIPRIO]), GFP_KERNEL); callbacks = kmalloc_array(fs->nvqs, sizeof(callbacks[VQ_HIPRIO]), GFP_KERNEL); @@ -723,12 +731,26 @@ static int virtio_fs_setup_vqs(struct virtio_device *vdev, names[i] = fs->vqs[i].name; } - ret = virtio_find_vqs(vdev, fs->nvqs, vqs, callbacks, names, NULL); + ret = virtio_find_vqs(vdev, fs->nvqs, vqs, callbacks, names, &desc); if (ret < 0) goto out; - for (i = 0; i < fs->nvqs; i++) + fs->vq_proxy = alloc_percpu(struct virtio_fs_vq *); + for (i = 0; i < fs->nvqs; i++) { + const struct cpumask *mask; + unsigned int cpu; + fs->vqs[i].vq = vqs[i]; + if (i == VQ_HIPRIO) + continue; + + mask = vdev->config->get_vq_affinity(vdev, i); + for_each_cpu(cpu, mask) { + struct virtio_fs_vq **cpu_vq = per_cpu_ptr(fs->vq_proxy, cpu); + *cpu_vq = &fs->vqs[i]; + pr_debug("virtio-fs: map cpu %d to vq%d\n", cpu, i); + } + } virtio_fs_start_all_queues(fs); out: @@ -875,8 +897,6 @@ static int virtio_fs_probe(struct virtio_device *vdev) if (ret < 0) goto out; - /* TODO vq affinity */ - ret = virtio_fs_setup_dax(vdev, fs); if (ret < 0) goto out_vqs; @@ -926,6 +946,7 @@ static void virtio_fs_remove(struct virtio_device *vdev) virtio_fs_stop_all_queues(fs); virtio_fs_drain_all_queues_locked(fs); virtio_reset_device(vdev); + free_percpu(fs->vq_proxy); virtio_fs_cleanup_vqs(vdev); vdev->priv = NULL; @@ -1223,7 +1244,6 @@ static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq, static void virtio_fs_wake_pending_and_unlock(struct fuse_iqueue *fiq) __releases(fiq->lock) { - unsigned int queue_id = VQ_REQUEST; /* TODO multiqueue */ struct virtio_fs *fs; struct fuse_req *req; struct virtio_fs_vq *fsvq; @@ -1243,7 +1263,8 @@ __releases(fiq->lock) req->in.h.nodeid, req->in.h.len, fuse_len_args(req->args->out_numargs, req->args->out_args)); - fsvq = &fs->vqs[queue_id]; + fsvq = this_cpu_read(*fs->vq_proxy); + ret = virtio_fs_enqueue_req(fsvq, req, false); if (ret < 0) { if (ret == -ENOMEM || ret == -ENOSPC) { -- 2.20.1
