From 0d9f0a52c8b9f7a003fe1650b7d5fb8518efabe0 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 5 Feb 2017 18:15:26 +0100 Subject: [PATCH] virtio_scsi: use virtio IRQ affinity Use automatic IRQ affinity assignment in the virtio layer if available, and build the blk-mq queues based on it. Signed-off-by: Christoph Hellwig Signed-off-by: Michael S. Tsirkin --- drivers/scsi/virtio_scsi.c | 126 ++++--------------------------------- include/linux/cpuhotplug.h | 1 - 2 files changed, 12 insertions(+), 115 deletions(-) diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c index c9c5ea0611e9..939c47df73fa 100644 --- a/drivers/scsi/virtio_scsi.c +++ b/drivers/scsi/virtio_scsi.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -29,6 +30,7 @@ #include #include #include +#include #define VIRTIO_SCSI_MEMPOOL_SZ 64 #define VIRTIO_SCSI_EVENT_LEN 8 @@ -108,7 +110,6 @@ struct virtio_scsi { bool affinity_hint_set; struct hlist_node node; - struct hlist_node node_dead; /* Protected by event_vq lock */ bool stop_events; @@ -118,7 +119,6 @@ struct virtio_scsi { struct virtio_scsi_vq req_vqs[]; }; -static enum cpuhp_state virtioscsi_online; static struct kmem_cache *virtscsi_cmd_cache; static mempool_t *virtscsi_cmd_pool; @@ -766,6 +766,13 @@ static void virtscsi_target_destroy(struct scsi_target *starget) kfree(tgt); } +static int virtscsi_map_queues(struct Scsi_Host *shost) +{ + struct virtio_scsi *vscsi = shost_priv(shost); + + return blk_mq_virtio_map_queues(&shost->tag_set, vscsi->vdev, 2); +} + static struct scsi_host_template virtscsi_host_template_single = { .module = THIS_MODULE, .name = "Virtio SCSI HBA", @@ -801,6 +808,7 @@ static struct scsi_host_template virtscsi_host_template_multi = { .use_clustering = ENABLE_CLUSTERING, .target_alloc = virtscsi_target_alloc, .target_destroy = virtscsi_target_destroy, + .map_queues = virtscsi_map_queues, .track_queue_depth = 1, }; @@ -817,80 +825,6 @@ static struct scsi_host_template virtscsi_host_template_multi = { virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ } while(0) -static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) -{ - int i; - int cpu; - - /* In multiqueue mode, when the number of cpu is equal - * to the number of request queues, we let the qeueues - * to be private to one cpu by setting the affinity hint - * to eliminate the contention. - */ - if ((vscsi->num_queues == 1 || - vscsi->num_queues != num_online_cpus()) && affinity) { - if (vscsi->affinity_hint_set) - affinity = false; - else - return; - } - - if (affinity) { - i = 0; - for_each_online_cpu(cpu) { - virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu); - i++; - } - - vscsi->affinity_hint_set = true; - } else { - for (i = 0; i < vscsi->num_queues; i++) { - if (!vscsi->req_vqs[i].vq) - continue; - - virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1); - } - - vscsi->affinity_hint_set = false; - } -} - -static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) -{ - get_online_cpus(); - __virtscsi_set_affinity(vscsi, affinity); - put_online_cpus(); -} - -static int virtscsi_cpu_online(unsigned int cpu, struct hlist_node *node) -{ - struct virtio_scsi *vscsi = hlist_entry_safe(node, struct virtio_scsi, - node); - __virtscsi_set_affinity(vscsi, true); - return 0; -} - -static int virtscsi_cpu_notif_add(struct virtio_scsi *vi) -{ - int ret; - - ret = cpuhp_state_add_instance(virtioscsi_online, &vi->node); - if (ret) - return ret; - - ret = cpuhp_state_add_instance(CPUHP_VIRT_SCSI_DEAD, &vi->node_dead); - if (ret) - cpuhp_state_remove_instance(virtioscsi_online, &vi->node); - return ret; -} - -static void virtscsi_cpu_notif_remove(struct virtio_scsi *vi) -{ - cpuhp_state_remove_instance_nocalls(virtioscsi_online, &vi->node); - cpuhp_state_remove_instance_nocalls(CPUHP_VIRT_SCSI_DEAD, - &vi->node_dead); -} - static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, struct virtqueue *vq) { @@ -900,14 +834,8 @@ static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, static void virtscsi_remove_vqs(struct virtio_device *vdev) { - struct Scsi_Host *sh = virtio_scsi_host(vdev); - struct virtio_scsi *vscsi = shost_priv(sh); - - virtscsi_set_affinity(vscsi, false); - /* Stop all the virtqueues. */ vdev->config->reset(vdev); - vdev->config->del_vqs(vdev); } @@ -920,6 +848,7 @@ static int virtscsi_init(struct virtio_device *vdev, vq_callback_t **callbacks; const char **names; struct virtqueue **vqs; + struct irq_affinity desc = { .pre_vectors = 2 }; num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL); @@ -942,7 +871,7 @@ static int virtscsi_init(struct virtio_device *vdev, /* Discover virtqueues and write information to configuration. */ err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names, - NULL); + &desc); if (err) goto out; @@ -1008,10 +937,6 @@ static int virtscsi_probe(struct virtio_device *vdev) if (err) goto virtscsi_init_failed; - err = virtscsi_cpu_notif_add(vscsi); - if (err) - goto scsi_add_host_failed; - cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; @@ -1066,9 +991,6 @@ static void virtscsi_remove(struct virtio_device *vdev) virtscsi_cancel_event_work(vscsi); scsi_remove_host(shost); - - virtscsi_cpu_notif_remove(vscsi); - virtscsi_remove_vqs(vdev); scsi_host_put(shost); } @@ -1076,10 +998,6 @@ static void virtscsi_remove(struct virtio_device *vdev) #ifdef CONFIG_PM_SLEEP static int virtscsi_freeze(struct virtio_device *vdev) { - struct Scsi_Host *sh = virtio_scsi_host(vdev); - struct virtio_scsi *vscsi = shost_priv(sh); - - virtscsi_cpu_notif_remove(vscsi); virtscsi_remove_vqs(vdev); return 0; } @@ -1094,11 +1012,6 @@ static int virtscsi_restore(struct virtio_device *vdev) if (err) return err; - err = virtscsi_cpu_notif_add(vscsi); - if (err) { - vdev->config->del_vqs(vdev); - return err; - } virtio_device_ready(vdev); if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) @@ -1153,16 +1066,6 @@ static int __init init(void) pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); goto error; } - ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, - "scsi/virtio:online", - virtscsi_cpu_online, NULL); - if (ret < 0) - goto error; - virtioscsi_online = ret; - ret = cpuhp_setup_state_multi(CPUHP_VIRT_SCSI_DEAD, "scsi/virtio:dead", - NULL, virtscsi_cpu_online); - if (ret) - goto error; ret = register_virtio_driver(&virtio_scsi_driver); if (ret < 0) goto error; @@ -1178,17 +1081,12 @@ error: kmem_cache_destroy(virtscsi_cmd_cache); virtscsi_cmd_cache = NULL; } - if (virtioscsi_online) - cpuhp_remove_multi_state(virtioscsi_online); - cpuhp_remove_multi_state(CPUHP_VIRT_SCSI_DEAD); return ret; } static void __exit fini(void) { unregister_virtio_driver(&virtio_scsi_driver); - cpuhp_remove_multi_state(virtioscsi_online); - cpuhp_remove_multi_state(CPUHP_VIRT_SCSI_DEAD); mempool_destroy(virtscsi_cmd_pool); kmem_cache_destroy(virtscsi_cmd_cache); } diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 921acaaa1601..01aea80a503e 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -26,7 +26,6 @@ enum cpuhp_state { CPUHP_ARM_OMAP_WAKE_DEAD, CPUHP_IRQ_POLL_DEAD, CPUHP_BLOCK_SOFTIRQ_DEAD, - CPUHP_VIRT_SCSI_DEAD, CPUHP_ACPI_CPUDRV_DEAD, CPUHP_S390_PFAULT_DEAD, CPUHP_BLK_MQ_DEAD, -- 2.20.1