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path: root/drivers/block/null_blk.c
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Diffstat (limited to 'drivers/block/null_blk.c')
-rw-r--r--drivers/block/null_blk.c120
1 files changed, 82 insertions, 38 deletions
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index ea192ec029c4..83a598ebb65a 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -1,4 +1,5 @@
#include <linux/module.h>
+
#include <linux/moduleparam.h>
#include <linux/sched.h>
#include <linux/fs.h>
@@ -65,7 +66,7 @@ enum {
NULL_Q_MQ = 2,
};
-static int submit_queues = 1;
+static int submit_queues;
module_param(submit_queues, int, S_IRUGO);
MODULE_PARM_DESC(submit_queues, "Number of submission queues");
@@ -101,9 +102,9 @@ static int hw_queue_depth = 64;
module_param(hw_queue_depth, int, S_IRUGO);
MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64");
-static bool use_per_node_hctx = true;
+static bool use_per_node_hctx = false;
module_param(use_per_node_hctx, bool, S_IRUGO);
-MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: true");
+MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false");
static void put_tag(struct nullb_queue *nq, unsigned int tag)
{
@@ -346,8 +347,37 @@ static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq)
static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_reg *reg, unsigned int hctx_index)
{
- return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL,
- hctx_index);
+ int b_size = DIV_ROUND_UP(reg->nr_hw_queues, nr_online_nodes);
+ int tip = (reg->nr_hw_queues % nr_online_nodes);
+ int node = 0, i, n;
+
+ /*
+ * Split submit queues evenly wrt to the number of nodes. If uneven,
+ * fill the first buckets with one extra, until the rest is filled with
+ * no extra.
+ */
+ for (i = 0, n = 1; i < hctx_index; i++, n++) {
+ if (n % b_size == 0) {
+ n = 0;
+ node++;
+
+ tip--;
+ if (!tip)
+ b_size = reg->nr_hw_queues / nr_online_nodes;
+ }
+ }
+
+ /*
+ * A node might not be online, therefore map the relative node id to the
+ * real node id.
+ */
+ for_each_online_node(n) {
+ if (!node)
+ break;
+ node--;
+ }
+
+ return kzalloc_node(sizeof(struct blk_mq_hw_ctx), GFP_KERNEL, n);
}
static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index)
@@ -355,16 +385,24 @@ static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index)
kfree(hctx);
}
+static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq)
+{
+ BUG_ON(!nullb);
+ BUG_ON(!nq);
+
+ init_waitqueue_head(&nq->wait);
+ nq->queue_depth = nullb->queue_depth;
+}
+
static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
unsigned int index)
{
struct nullb *nullb = data;
struct nullb_queue *nq = &nullb->queues[index];
- init_waitqueue_head(&nq->wait);
- nq->queue_depth = nullb->queue_depth;
- nullb->nr_queues++;
hctx->driver_data = nq;
+ null_init_queue(nullb, nq);
+ nullb->nr_queues++;
return 0;
}
@@ -387,10 +425,7 @@ static void null_del_dev(struct nullb *nullb)
list_del_init(&nullb->list);
del_gendisk(nullb->disk);
- if (queue_mode == NULL_Q_MQ)
- blk_mq_free_queue(nullb->q);
- else
- blk_cleanup_queue(nullb->q);
+ blk_cleanup_queue(nullb->q);
put_disk(nullb->disk);
kfree(nullb);
}
@@ -417,13 +452,13 @@ static int setup_commands(struct nullb_queue *nq)
nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL);
if (!nq->cmds)
- return 1;
+ return -ENOMEM;
tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG;
nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL);
if (!nq->tag_map) {
kfree(nq->cmds);
- return 1;
+ return -ENOMEM;
}
for (i = 0; i < nq->queue_depth; i++) {
@@ -454,33 +489,37 @@ static void cleanup_queues(struct nullb *nullb)
static int setup_queues(struct nullb *nullb)
{
- struct nullb_queue *nq;
- int i;
-
- nullb->queues = kzalloc(submit_queues * sizeof(*nq), GFP_KERNEL);
+ nullb->queues = kzalloc(submit_queues * sizeof(struct nullb_queue),
+ GFP_KERNEL);
if (!nullb->queues)
- return 1;
+ return -ENOMEM;
nullb->nr_queues = 0;
nullb->queue_depth = hw_queue_depth;
- if (queue_mode == NULL_Q_MQ)
- return 0;
+ return 0;
+}
+
+static int init_driver_queues(struct nullb *nullb)
+{
+ struct nullb_queue *nq;
+ int i, ret = 0;
for (i = 0; i < submit_queues; i++) {
nq = &nullb->queues[i];
- init_waitqueue_head(&nq->wait);
- nq->queue_depth = hw_queue_depth;
- if (setup_commands(nq))
- break;
+
+ null_init_queue(nullb, nq);
+
+ ret = setup_commands(nq);
+ if (ret)
+ goto err_queue;
nullb->nr_queues++;
}
- if (i == submit_queues)
- return 0;
-
+ return 0;
+err_queue:
cleanup_queues(nullb);
- return 1;
+ return ret;
}
static int null_add_dev(void)
@@ -495,34 +534,36 @@ static int null_add_dev(void)
spin_lock_init(&nullb->lock);
+ if (queue_mode == NULL_Q_MQ && use_per_node_hctx)
+ submit_queues = nr_online_nodes;
+
if (setup_queues(nullb))
goto err;
if (queue_mode == NULL_Q_MQ) {
null_mq_reg.numa_node = home_node;
null_mq_reg.queue_depth = hw_queue_depth;
+ null_mq_reg.nr_hw_queues = submit_queues;
if (use_per_node_hctx) {
null_mq_reg.ops->alloc_hctx = null_alloc_hctx;
null_mq_reg.ops->free_hctx = null_free_hctx;
-
- null_mq_reg.nr_hw_queues = nr_online_nodes;
} else {
null_mq_reg.ops->alloc_hctx = blk_mq_alloc_single_hw_queue;
null_mq_reg.ops->free_hctx = blk_mq_free_single_hw_queue;
-
- null_mq_reg.nr_hw_queues = submit_queues;
}
nullb->q = blk_mq_init_queue(&null_mq_reg, nullb);
} else if (queue_mode == NULL_Q_BIO) {
nullb->q = blk_alloc_queue_node(GFP_KERNEL, home_node);
blk_queue_make_request(nullb->q, null_queue_bio);
+ init_driver_queues(nullb);
} else {
nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock, home_node);
blk_queue_prep_rq(nullb->q, null_rq_prep_fn);
if (nullb->q)
blk_queue_softirq_done(nullb->q, null_softirq_done_fn);
+ init_driver_queues(nullb);
}
if (!nullb->q)
@@ -534,10 +575,7 @@ static int null_add_dev(void)
disk = nullb->disk = alloc_disk_node(1, home_node);
if (!disk) {
queue_fail:
- if (queue_mode == NULL_Q_MQ)
- blk_mq_free_queue(nullb->q);
- else
- blk_cleanup_queue(nullb->q);
+ blk_cleanup_queue(nullb->q);
cleanup_queues(nullb);
err:
kfree(nullb);
@@ -579,7 +617,13 @@ static int __init null_init(void)
}
#endif
- if (submit_queues > nr_cpu_ids)
+ if (queue_mode == NULL_Q_MQ && use_per_node_hctx) {
+ if (submit_queues < nr_online_nodes) {
+ pr_warn("null_blk: submit_queues param is set to %u.",
+ nr_online_nodes);
+ submit_queues = nr_online_nodes;
+ }
+ } else if (submit_queues > nr_cpu_ids)
submit_queues = nr_cpu_ids;
else if (!submit_queues)
submit_queues = 1;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 00:40:35 +0100