diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index e9495f0bfad30d19a8604aa17d687e9ae60a19bd..48d7bd55207a452f43f37ba118d8695e05bf260b 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -20,6 +20,7 @@
#include <linux/bio.h>
#include <linux/bitops.h>
#include <linux/blkdev.h>
+#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/fs.h>
@@ -35,6 +36,7 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
+#include <linux/percpu.h>
#include <linux/poison.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
@@ -96,6 +98,7 @@ struct nvme_queue {
u8 cq_phase;
u8 cqe_seen;
u8 q_suspended;
+ cpumask_var_t cpu_mask;
struct async_cmd_info cmdinfo;
unsigned long cmdid_data[];
};
@@ -270,14 +273,15 @@ static struct nvme_queue *raw_nvmeq(struct nvme_dev *dev, int qid)
static struct nvme_queue *get_nvmeq(struct nvme_dev *dev) __acquires(RCU)
{
+ unsigned queue_id = get_cpu_var(*dev->io_queue);
rcu_read_lock();
- return rcu_dereference(dev->queues[get_cpu() + 1]);
+ return rcu_dereference(dev->queues[queue_id]);
}
static void put_nvmeq(struct nvme_queue *nvmeq) __releases(RCU)
{
- put_cpu();
rcu_read_unlock();
+ put_cpu_var(nvmeq->dev->io_queue);
}
static struct nvme_queue *lock_nvmeq(struct nvme_dev *dev, int q_idx)
@@ -1121,6 +1125,8 @@ static void nvme_free_queue(struct rcu_head *r)
(void *)nvmeq->cqes, nvmeq->cq_dma_addr);
dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
nvmeq->sq_cmds, nvmeq->sq_dma_addr);
+ if (nvmeq->qid)
+ free_cpumask_var(nvmeq->cpu_mask);
kfree(nvmeq);
}
@@ -1128,8 +1134,6 @@ static void nvme_free_queues(struct nvme_dev *dev, int lowest)
{
int i;
- for (i = num_possible_cpus(); i > dev->queue_count - 1; i--)
- rcu_assign_pointer(dev->queues[i], NULL);
for (i = dev->queue_count - 1; i >= lowest; i--) {
struct nvme_queue *nvmeq = raw_nvmeq(dev, i);
rcu_assign_pointer(dev->queues[i], NULL);
@@ -1154,6 +1158,7 @@ static int nvme_suspend_queue(struct nvme_queue *nvmeq)
return 1;
}
nvmeq->q_suspended = 1;
+ nvmeq->dev->online_queues--;
spin_unlock_irq(&nvmeq->q_lock);
irq_set_affinity_hint(vector, NULL);
@@ -1208,6 +1213,9 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
if (!nvmeq->sq_cmds)
goto free_cqdma;
+ if (qid && !zalloc_cpumask_var(&nvmeq->cpu_mask, GFP_KERNEL))
+ goto free_sqdma;
+
nvmeq->q_dmadev = dmadev;
nvmeq->dev = dev;
snprintf(nvmeq->irqname, sizeof(nvmeq->irqname), "nvme%dq%d",
@@ -1228,6 +1236,9 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
return nvmeq;
+ free_sqdma:
+ dma_free_coherent(dmadev, SQ_SIZE(depth), (void *)nvmeq->sq_cmds,
+ nvmeq->sq_dma_addr);
free_cqdma:
dma_free_coherent(dmadev, CQ_SIZE(depth), (void *)nvmeq->cqes,
nvmeq->cq_dma_addr);
@@ -1260,6 +1271,7 @@ static void nvme_init_queue(struct nvme_queue *nvmeq, u16 qid)
memset((void *)nvmeq->cqes, 0, CQ_SIZE(nvmeq->q_depth));
nvme_cancel_ios(nvmeq, false);
nvmeq->q_suspended = 0;
+ dev->online_queues++;
}
static int nvme_create_queue(struct nvme_queue *nvmeq, int qid)
@@ -1835,6 +1847,143 @@ static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid,
return NULL;
}
+static int nvme_find_closest_node(int node)
+{
+ int n, val, min_val = INT_MAX, best_node = node;
+
+ for_each_online_node(n) {
+ if (n == node)
+ continue;
+ val = node_distance(node, n);
+ if (val < min_val) {
+ min_val = val;
+ best_node = n;
+ }
+ }
+ return best_node;
+}
+
+static void nvme_set_queue_cpus(cpumask_t *qmask, struct nvme_queue *nvmeq,
+ int count)
+{
+ int cpu;
+ for_each_cpu(cpu, qmask) {
+ if (cpumask_weight(nvmeq->cpu_mask) >= count)
+ break;
+ if (!cpumask_test_and_set_cpu(cpu, nvmeq->cpu_mask))
+ *per_cpu_ptr(nvmeq->dev->io_queue, cpu) = nvmeq->qid;
+ }
+}
+
+static void nvme_add_cpus(cpumask_t *mask, const cpumask_t *unassigned_cpus,
+ const cpumask_t *new_mask, struct nvme_queue *nvmeq, int cpus_per_queue)
+{
+ int next_cpu;
+ for_each_cpu(next_cpu, new_mask) {
+ cpumask_or(mask, mask, get_cpu_mask(next_cpu));
+ cpumask_or(mask, mask, topology_thread_cpumask(next_cpu));
+ cpumask_and(mask, mask, unassigned_cpus);
+ nvme_set_queue_cpus(mask, nvmeq, cpus_per_queue);
+ }
+}
+
+static void nvme_create_io_queues(struct nvme_dev *dev)
+{
+ unsigned i, max;
+
+ max = min(dev->max_qid, num_online_cpus());
+ for (i = dev->queue_count; i <= max; i++)
+ if (!nvme_alloc_queue(dev, i, dev->q_depth, i - 1))
+ break;
+
+ max = min(dev->queue_count - 1, num_online_cpus());
+ for (i = dev->online_queues; i <= max; i++)
+ if (nvme_create_queue(raw_nvmeq(dev, i), i))
+ break;
+}
+
+/*
+ * If there are fewer queues than online cpus, this will try to optimally
+ * assign a queue to multiple cpus by grouping cpus that are "close" together:
+ * thread siblings, core, socket, closest node, then whatever else is
+ * available.
+ */
+static void nvme_assign_io_queues(struct nvme_dev *dev)
+{
+ unsigned cpu, cpus_per_queue, queues, remainder, i;
+ cpumask_var_t unassigned_cpus;
+
+ nvme_create_io_queues(dev);
+
+ queues = min(dev->online_queues - 1, num_online_cpus());
+ if (!queues)
+ return;
+
+ cpus_per_queue = num_online_cpus() / queues;
+ remainder = queues - (num_online_cpus() - queues * cpus_per_queue);
+
+ if (!alloc_cpumask_var(&unassigned_cpus, GFP_KERNEL))
+ return;
+
+ cpumask_copy(unassigned_cpus, cpu_online_mask);
+ cpu = cpumask_first(unassigned_cpus);
+ for (i = 1; i <= queues; i++) {
+ struct nvme_queue *nvmeq = lock_nvmeq(dev, i);
+ cpumask_t mask;
+
+ cpumask_clear(nvmeq->cpu_mask);
+ if (!cpumask_weight(unassigned_cpus)) {
+ unlock_nvmeq(nvmeq);
+ break;
+ }
+
+ mask = *get_cpu_mask(cpu);
+ nvme_set_queue_cpus(&mask, nvmeq, cpus_per_queue);
+ if (cpus_weight(mask) < cpus_per_queue)
+ nvme_add_cpus(&mask, unassigned_cpus,
+ topology_thread_cpumask(cpu),
+ nvmeq, cpus_per_queue);
+ if (cpus_weight(mask) < cpus_per_queue)
+ nvme_add_cpus(&mask, unassigned_cpus,
+ topology_core_cpumask(cpu),
+ nvmeq, cpus_per_queue);
+ if (cpus_weight(mask) < cpus_per_queue)
+ nvme_add_cpus(&mask, unassigned_cpus,
+ cpumask_of_node(cpu_to_node(cpu)),
+ nvmeq, cpus_per_queue);
+ if (cpus_weight(mask) < cpus_per_queue)
+ nvme_add_cpus(&mask, unassigned_cpus,
+ cpumask_of_node(
+ nvme_find_closest_node(
+ cpu_to_node(cpu))),
+ nvmeq, cpus_per_queue);
+ if (cpus_weight(mask) < cpus_per_queue)
+ nvme_add_cpus(&mask, unassigned_cpus,
+ unassigned_cpus,
+ nvmeq, cpus_per_queue);
+
+ WARN(cpumask_weight(nvmeq->cpu_mask) != cpus_per_queue,
+ "nvme%d qid:%d mis-matched queue-to-cpu assignment\n",
+ dev->instance, i);
+
+ irq_set_affinity_hint(dev->entry[nvmeq->cq_vector].vector,
+ nvmeq->cpu_mask);
+ cpumask_andnot(unassigned_cpus, unassigned_cpus,
+ nvmeq->cpu_mask);
+ cpu = cpumask_next(cpu, unassigned_cpus);
+ if (remainder && !--remainder)
+ cpus_per_queue++;
+ unlock_nvmeq(nvmeq);
+ }
+ WARN(cpumask_weight(unassigned_cpus), "nvme%d unassigned online cpus\n",
+ dev->instance);
+ i = 0;
+ cpumask_andnot(unassigned_cpus, cpu_possible_mask, cpu_online_mask);
+ for_each_cpu(cpu, unassigned_cpus)
+ *per_cpu_ptr(dev->io_queue, cpu) = (i++ % queues) + 1;
+ free_cpumask_var(unassigned_cpus);
+}
+
static int set_queue_count(struct nvme_dev *dev, int count)
{
int status;
@@ -1857,9 +2006,9 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
{
struct nvme_queue *adminq = raw_nvmeq(dev, 0);
struct pci_dev *pdev = dev->pci_dev;
- int result, cpu, i, vecs, nr_io_queues, size, q_depth;
+ int result, i, vecs, nr_io_queues, size;
- nr_io_queues = num_online_cpus();
+ nr_io_queues = num_possible_cpus();
result = set_queue_count(dev, nr_io_queues);
if (result < 0)
return result;
@@ -1919,6 +2068,7 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
* number of interrupts.
*/
nr_io_queues = vecs;
+ dev->max_qid = nr_io_queues;
result = queue_request_irq(dev, adminq, adminq->irqname);
if (result) {
@@ -1927,36 +2077,8 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
}
/* Free previously allocated queues that are no longer usable */
- nvme_free_queues(dev, nr_io_queues);
-
- cpu = cpumask_first(cpu_online_mask);
- for (i = 0; i < nr_io_queues; i++) {
- irq_set_affinity_hint(dev->entry[i].vector, get_cpu_mask(cpu));
- cpu = cpumask_next(cpu, cpu_online_mask);
- }
-
- q_depth = min_t(int, NVME_CAP_MQES(readq(&dev->bar->cap)) + 1,
- NVME_Q_DEPTH);
- for (i = dev->queue_count - 1; i < nr_io_queues; i++) {
- if (!nvme_alloc_queue(dev, i + 1, q_depth, i)) {
- result = -ENOMEM;
- goto free_queues;
- }
- }
-
- for (; i < num_possible_cpus(); i++) {
- int target = i % rounddown_pow_of_two(dev->queue_count - 1);
- rcu_assign_pointer(dev->queues[i + 1], dev->queues[target + 1]);
- }
-
- for (i = 1; i < dev->queue_count; i++) {
- result = nvme_create_queue(raw_nvmeq(dev, i), i);
- if (result) {
- for (--i; i > 0; i--)
- nvme_disable_queue(dev, i);
- goto free_queues;
- }
- }
+ nvme_free_queues(dev, nr_io_queues + 1);
+ nvme_assign_io_queues(dev);
return 0;
@@ -2035,6 +2157,7 @@ static int nvme_dev_add(struct nvme_dev *dev)
static int nvme_dev_map(struct nvme_dev *dev)
{
+ u64 cap;
int bars, result = -ENOMEM;
struct pci_dev *pdev = dev->pci_dev;
@@ -2058,7 +2181,9 @@ static int nvme_dev_map(struct nvme_dev *dev)
result = -ENODEV;
goto unmap;
}
- dev->db_stride = 1 << NVME_CAP_STRIDE(readq(&dev->bar->cap));
+ cap = readq(&dev->bar->cap);
+ dev->q_depth = min_t(int, NVME_CAP_MQES(cap) + 1, NVME_Q_DEPTH);
+ dev->db_stride = 1 << NVME_CAP_STRIDE(cap);
dev->dbs = ((void __iomem *)dev->bar) + 4096;
return 0;
@@ -2332,6 +2457,7 @@ static void nvme_free_dev(struct kref *kref)
struct nvme_dev *dev = container_of(kref, struct nvme_dev, kref);
nvme_free_namespaces(dev);
+ free_percpu(dev->io_queue);
kfree(dev->queues);
kfree(dev->entry);
kfree(dev);
@@ -2477,6 +2603,9 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
GFP_KERNEL);
if (!dev->queues)
goto free;
+ dev->io_queue = alloc_percpu(unsigned short);
+ if (!dev->io_queue)
+ goto free;
INIT_LIST_HEAD(&dev->namespaces);
INIT_WORK(&dev->reset_work, nvme_reset_failed_dev);
@@ -2526,6 +2655,7 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
release:
nvme_release_instance(dev);
free:
+ free_percpu(dev->io_queue);
kfree(dev->queues);
kfree(dev->entry);
kfree(dev);
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 7c3f85bc10f19d9c5a3db0e232cf32384a0507b3..f0f95c7196850d2cdd13960c2aa76b034e36bc7e 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -74,12 +74,16 @@ enum {
struct nvme_dev {
struct list_head node;
struct nvme_queue __rcu **queues;
+ unsigned short __percpu *io_queue;
u32 __iomem *dbs;
struct pci_dev *pci_dev;
struct dma_pool *prp_page_pool;
struct dma_pool *prp_small_pool;
int instance;
- int queue_count;
+ unsigned queue_count;
+ unsigned online_queues;
+ unsigned max_qid;
+ int q_depth;
u32 db_stride;
u32 ctrl_config;
struct msix_entry *entry;