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blk-mq: split out tag initialization, support shared tags

Browse Source 
Add a new blk_mq_tag_set structure that gets set up before we initialize
the queue.  A single blk_mq_tag_set structure can be shared by multiple
queues.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Modular export of blk_mq_{alloc,free}_tagset added by me.

Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Christoph Hellwig 2014-04-15 14:14:00 -06:00 committed by Jens Axboe
parent ed44832dea
commit 24d2f90309
8 changed files with 260 additions and 198 deletions
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6
block/blk-mq-cpumap.c
View File

@ -80,17 +80,17 @@ int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues)
return 0;
}
unsigned int *blk_mq_make_queue_map(struct blk_mq_reg *reg)
unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set)
{
unsigned int *map;
/* If cpus are offline, map them to first hctx */
map = kzalloc_node(sizeof(*map) * num_possible_cpus(), GFP_KERNEL,
reg->numa_node);
set->numa_node);
if (!map)
return NULL;
if (!blk_mq_update_queue_map(map, reg->nr_hw_queues))
if (!blk_mq_update_queue_map(map, set->nr_hw_queues))
return map;
kfree(map);

14
block/blk-mq-tag.c
View File

@ -1,25 +1,11 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/percpu_ida.h>
#include <linux/blk-mq.h>
#include "blk.h"
#include "blk-mq.h"
#include "blk-mq-tag.h"
/*
* Per tagged queue (tag address space) map
*/
struct blk_mq_tags {
unsigned int nr_tags;
unsigned int nr_reserved_tags;
unsigned int nr_batch_move;
unsigned int nr_max_cache;
struct percpu_ida free_tags;
struct percpu_ida reserved_tags;
};
void blk_mq_wait_for_tags(struct blk_mq_tags *tags)
{
int tag = blk_mq_get_tag(tags, __GFP_WAIT, false);

19
block/blk-mq-tag.h
View File

@ -1,7 +1,24 @@
#ifndef INT_BLK_MQ_TAG_H
#define INT_BLK_MQ_TAG_H
struct blk_mq_tags;
#include <linux/percpu_ida.h>
/*
* Tag address space map.
*/
struct blk_mq_tags {
unsigned int nr_tags;
unsigned int nr_reserved_tags;
unsigned int nr_batch_move;
unsigned int nr_max_cache;
struct percpu_ida free_tags;
struct percpu_ida reserved_tags;
struct request **rqs;
struct list_head page_list;
};
extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node);
extern void blk_mq_free_tags(struct blk_mq_tags *tags);

244
block/blk-mq.c
View File

@ -81,7 +81,7 @@ static struct request *__blk_mq_alloc_request(struct blk_mq_hw_ctx *hctx,
tag = blk_mq_get_tag(hctx->tags, gfp, reserved);
if (tag != BLK_MQ_TAG_FAIL) {
rq = hctx->rqs[tag];
rq = hctx->tags->rqs[tag];
blk_rq_init(hctx->queue, rq);
rq->tag = tag;
@ -404,6 +404,12 @@ static void blk_mq_requeue_request(struct request *rq)
rq->nr_phys_segments--;
}
struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
{
return tags->rqs[tag];
}
EXPORT_SYMBOL(blk_mq_tag_to_rq);
struct blk_mq_timeout_data {
struct blk_mq_hw_ctx *hctx;
unsigned long *next;
@ -425,12 +431,13 @@ static void blk_mq_timeout_check(void *__data, unsigned long *free_tags)
do {
struct request *rq;
tag = find_next_zero_bit(free_tags, hctx->queue_depth, tag);
if (tag >= hctx->queue_depth)
tag = find_next_zero_bit(free_tags, hctx->tags->nr_tags, tag);
if (tag >= hctx->tags->nr_tags)
break;
rq = hctx->rqs[tag++];
rq = blk_mq_tag_to_rq(hctx->tags, tag++);
if (rq->q != hctx->queue)
continue;
if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
continue;
@ -969,11 +976,11 @@ struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu)
}
EXPORT_SYMBOL(blk_mq_map_queue);
struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *reg,
struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *set,
unsigned int hctx_index)
{
return kmalloc_node(sizeof(struct blk_mq_hw_ctx),
GFP_KERNEL | __GFP_ZERO, reg->numa_node);
GFP_KERNEL | __GFP_ZERO, set->numa_node);
}
EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue);
@ -1030,31 +1037,31 @@ static void blk_mq_hctx_notify(void *data, unsigned long action,
blk_mq_put_ctx(ctx);
}
static void blk_mq_free_rq_map(struct blk_mq_hw_ctx *hctx, void *driver_data)
static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
struct blk_mq_tags *tags, unsigned int hctx_idx)
{
struct page *page;
if (hctx->rqs && hctx->queue->mq_ops->exit_request) {
if (tags->rqs && set->ops->exit_request) {
int i;
for (i = 0; i < hctx->queue_depth; i++) {
if (!hctx->rqs[i])
for (i = 0; i < tags->nr_tags; i++) {
if (!tags->rqs[i])
continue;
hctx->queue->mq_ops->exit_request(driver_data, hctx,
hctx->rqs[i], i);
set->ops->exit_request(set->driver_data, tags->rqs[i],
hctx_idx, i);
}
}
while (!list_empty(&hctx->page_list)) {
page = list_first_entry(&hctx->page_list, struct page, lru);
while (!list_empty(&tags->page_list)) {
page = list_first_entry(&tags->page_list, struct page, lru);
list_del_init(&page->lru);
__free_pages(page, page->private);
}
kfree(hctx->rqs);
kfree(tags->rqs);
if (hctx->tags)
blk_mq_free_tags(hctx->tags);
blk_mq_free_tags(tags);
}
static size_t order_to_size(unsigned int order)
@ -1067,30 +1074,36 @@ static size_t order_to_size(unsigned int order)
return ret;
}
static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx,
struct blk_mq_reg *reg, void *driver_data, int node)
static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
unsigned int hctx_idx)
{
unsigned int reserved_tags = reg->reserved_tags;
struct blk_mq_tags *tags;
unsigned int i, j, entries_per_page, max_order = 4;
size_t rq_size, left;
int error;
INIT_LIST_HEAD(&hctx->page_list);
tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags,
set->numa_node);
if (!tags)
return NULL;
hctx->rqs = kmalloc_node(hctx->queue_depth * sizeof(struct request *),
GFP_KERNEL, node);
if (!hctx->rqs)
return -ENOMEM;
INIT_LIST_HEAD(&tags->page_list);
tags->rqs = kmalloc_node(set->queue_depth * sizeof(struct request *),
GFP_KERNEL, set->numa_node);
if (!tags->rqs) {
blk_mq_free_tags(tags);
return NULL;
}
/*
* rq_size is the size of the request plus driver payload, rounded
* to the cacheline size
*/
rq_size = round_up(sizeof(struct request) + hctx->cmd_size,
rq_size = round_up(sizeof(struct request) + set->cmd_size,
cache_line_size());
left = rq_size * hctx->queue_depth;
left = rq_size * set->queue_depth;
for (i = 0; i < hctx->queue_depth;) {
for (i = 0; i < set->queue_depth; ) {
int this_order = max_order;
struct page *page;
int to_do;
@ -1100,7 +1113,8 @@ static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx,
this_order--;
do {
page = alloc_pages_node(node, GFP_KERNEL, this_order);
page = alloc_pages_node(set->numa_node, GFP_KERNEL,
this_order);
if (page)
break;
if (!this_order--)
@ -1110,22 +1124,22 @@ static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx,
} while (1);
if (!page)
break;
goto fail;
page->private = this_order;
list_add_tail(&page->lru, &hctx->page_list);
list_add_tail(&page->lru, &tags->page_list);
p = page_address(page);
entries_per_page = order_to_size(this_order) / rq_size;
to_do = min(entries_per_page, hctx->queue_depth - i);
to_do = min(entries_per_page, set->queue_depth - i);
left -= to_do * rq_size;
for (j = 0; j < to_do; j++) {
hctx->rqs[i] = p;
if (reg->ops->init_request) {
error = reg->ops->init_request(driver_data,
hctx, hctx->rqs[i], i);
if (error)
goto err_rq_map;
tags->rqs[i] = p;
if (set->ops->init_request) {
if (set->ops->init_request(set->driver_data,
tags->rqs[i], hctx_idx, i,
set->numa_node))
goto fail;
}
p += rq_size;
@ -1133,30 +1147,16 @@ static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx,
}
}
if (i < (reserved_tags + BLK_MQ_TAG_MIN)) {
error = -ENOMEM;
goto err_rq_map;
}
if (i != hctx->queue_depth) {
hctx->queue_depth = i;
pr_warn("%s: queue depth set to %u because of low memory\n",
__func__, i);
}
return tags;
hctx->tags = blk_mq_init_tags(hctx->queue_depth, reserved_tags, node);
if (!hctx->tags) {
error = -ENOMEM;
goto err_rq_map;
}
return 0;
err_rq_map:
blk_mq_free_rq_map(hctx, driver_data);
return error;
fail:
pr_warn("%s: failed to allocate requests\n", __func__);
blk_mq_free_rq_map(set, tags, hctx_idx);
return NULL;
}
static int blk_mq_init_hw_queues(struct request_queue *q,
struct blk_mq_reg *reg, void *driver_data)
struct blk_mq_tag_set *set)
{
struct blk_mq_hw_ctx *hctx;
unsigned int i, j;
@ -1170,23 +1170,21 @@ static int blk_mq_init_hw_queues(struct request_queue *q,
node = hctx->numa_node;
if (node == NUMA_NO_NODE)
node = hctx->numa_node = reg->numa_node;
node = hctx->numa_node = set->numa_node;
INIT_DELAYED_WORK(&hctx->delayed_work, blk_mq_work_fn);
spin_lock_init(&hctx->lock);
INIT_LIST_HEAD(&hctx->dispatch);
hctx->queue = q;
hctx->queue_num = i;
hctx->flags = reg->flags;
hctx->queue_depth = reg->queue_depth;
hctx->cmd_size = reg->cmd_size;
hctx->flags = set->flags;
hctx->cmd_size = set->cmd_size;
blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
blk_mq_hctx_notify, hctx);
blk_mq_register_cpu_notifier(&hctx->cpu_notifier);
if (blk_mq_init_rq_map(hctx, reg, driver_data, node))
break;
hctx->tags = set->tags[i];
/*
* Allocate space for all possible cpus to avoid allocation in
@ -1206,8 +1204,8 @@ static int blk_mq_init_hw_queues(struct request_queue *q,
hctx->nr_ctx_map = num_maps;
hctx->nr_ctx = 0;
if (reg->ops->init_hctx &&
reg->ops->init_hctx(hctx, driver_data, i))
if (set->ops->init_hctx &&
set->ops->init_hctx(hctx, set->driver_data, i))
break;
}
@ -1221,11 +1219,10 @@ static int blk_mq_init_hw_queues(struct request_queue *q,
if (i == j)
break;
if (reg->ops->exit_hctx)
reg->ops->exit_hctx(hctx, j);
if (set->ops->exit_hctx)
set->ops->exit_hctx(hctx, j);
blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
blk_mq_free_rq_map(hctx, driver_data);
kfree(hctx->ctxs);
}
@ -1290,41 +1287,25 @@ static void blk_mq_map_swqueue(struct request_queue *q)
}
}
struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg,
void *driver_data)
struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
{
struct blk_mq_hw_ctx **hctxs;
struct blk_mq_ctx *ctx;
struct request_queue *q;
int i;
if (!reg->nr_hw_queues ||
!reg->ops->queue_rq || !reg->ops->map_queue ||
!reg->ops->alloc_hctx || !reg->ops->free_hctx)
return ERR_PTR(-EINVAL);
if (!reg->queue_depth)
reg->queue_depth = BLK_MQ_MAX_DEPTH;
else if (reg->queue_depth > BLK_MQ_MAX_DEPTH) {
pr_err("blk-mq: queuedepth too large (%u)\n", reg->queue_depth);
reg->queue_depth = BLK_MQ_MAX_DEPTH;
}
if (reg->queue_depth < (reg->reserved_tags + BLK_MQ_TAG_MIN))
return ERR_PTR(-EINVAL);
ctx = alloc_percpu(struct blk_mq_ctx);
if (!ctx)
return ERR_PTR(-ENOMEM);
hctxs = kmalloc_node(reg->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
reg->numa_node);
hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
set->numa_node);
if (!hctxs)
goto err_percpu;
for (i = 0; i < reg->nr_hw_queues; i++) {
hctxs[i] = reg->ops->alloc_hctx(reg, i);
for (i = 0; i < set->nr_hw_queues; i++) {
hctxs[i] = set->ops->alloc_hctx(set, i);
if (!hctxs[i])
goto err_hctxs;
@ -1335,11 +1316,11 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg,
hctxs[i]->queue_num = i;
}
q = blk_alloc_queue_node(GFP_KERNEL, reg->numa_node);
q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node);
if (!q)
goto err_hctxs;
q->mq_map = blk_mq_make_queue_map(reg);
q->mq_map = blk_mq_make_queue_map(set);
if (!q->mq_map)
goto err_map;
@ -1347,33 +1328,34 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_reg *reg,
blk_queue_rq_timeout(q, 30000);
q->nr_queues = nr_cpu_ids;
q->nr_hw_queues = reg->nr_hw_queues;
q->nr_hw_queues = set->nr_hw_queues;
q->queue_ctx = ctx;
q->queue_hw_ctx = hctxs;
q->mq_ops = reg->ops;
q->mq_ops = set->ops;
q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
q->sg_reserved_size = INT_MAX;
blk_queue_make_request(q, blk_mq_make_request);
blk_queue_rq_timed_out(q, reg->ops->timeout);
if (reg->timeout)
blk_queue_rq_timeout(q, reg->timeout);
blk_queue_rq_timed_out(q, set->ops->timeout);
if (set->timeout)
blk_queue_rq_timeout(q, set->timeout);
if (reg->ops->complete)
blk_queue_softirq_done(q, reg->ops->complete);
if (set->ops->complete)
blk_queue_softirq_done(q, set->ops->complete);
blk_mq_init_flush(q);
blk_mq_init_cpu_queues(q, reg->nr_hw_queues);
blk_mq_init_cpu_queues(q, set->nr_hw_queues);
q->flush_rq = kzalloc(round_up(sizeof(struct request) + reg->cmd_size,
cache_line_size()), GFP_KERNEL);
q->flush_rq = kzalloc(round_up(sizeof(struct request) +
set->cmd_size, cache_line_size()),
GFP_KERNEL);
if (!q->flush_rq)
goto err_hw;
if (blk_mq_init_hw_queues(q, reg, driver_data))
if (blk_mq_init_hw_queues(q, set))
goto err_flush_rq;
blk_mq_map_swqueue(q);
@ -1391,11 +1373,11 @@ err_hw:
err_map:
blk_cleanup_queue(q);
err_hctxs:
for (i = 0; i < reg->nr_hw_queues; i++) {
for (i = 0; i < set->nr_hw_queues; i++) {
if (!hctxs[i])
break;
free_cpumask_var(hctxs[i]->cpumask);
reg->ops->free_hctx(hctxs[i], i);
set->ops->free_hctx(hctxs[i], i);
}
kfree(hctxs);
err_percpu:
@ -1412,7 +1394,6 @@ void blk_mq_free_queue(struct request_queue *q)
queue_for_each_hw_ctx(q, hctx, i) {
kfree(hctx->ctx_map);
kfree(hctx->ctxs);
blk_mq_free_rq_map(hctx, q->queuedata);
blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
if (q->mq_ops->exit_hctx)
q->mq_ops->exit_hctx(hctx, i);
@ -1473,6 +1454,53 @@ static int blk_mq_queue_reinit_notify(struct notifier_block *nb,
return NOTIFY_OK;
}
int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
{
int i;
if (!set->nr_hw_queues)
return -EINVAL;
if (!set->queue_depth || set->queue_depth > BLK_MQ_MAX_DEPTH)
return -EINVAL;
if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
return -EINVAL;
if (!set->nr_hw_queues ||
!set->ops->queue_rq || !set->ops->map_queue ||
!set->ops->alloc_hctx || !set->ops->free_hctx)
return -EINVAL;
set->tags = kmalloc_node(set->nr_hw_queues * sizeof(struct blk_mq_tags),
GFP_KERNEL, set->numa_node);
if (!set->tags)
goto out;
for (i = 0; i < set->nr_hw_queues; i++) {
set->tags[i] = blk_mq_init_rq_map(set, i);
if (!set->tags[i])
goto out_unwind;
}
return 0;
out_unwind:
while (--i >= 0)
blk_mq_free_rq_map(set, set->tags[i], i);
out:
return -ENOMEM;
}
EXPORT_SYMBOL(blk_mq_alloc_tag_set);
void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
{
int i;
for (i = 0; i < set->nr_hw_queues; i++)
blk_mq_free_rq_map(set, set->tags[i], i);
}
EXPORT_SYMBOL(blk_mq_free_tag_set);
void blk_mq_disable_hotplug(void)
{
mutex_lock(&all_q_mutex);

5
block/blk-mq.h
View File

@ -1,6 +1,8 @@
#ifndef INT_BLK_MQ_H
#define INT_BLK_MQ_H
struct blk_mq_tag_set;
struct blk_mq_ctx {
struct {
spinlock_t lock;
@ -46,8 +48,7 @@ void blk_mq_disable_hotplug(void);
/*
* CPU -> queue mappings
*/
struct blk_mq_reg;
extern unsigned int *blk_mq_make_queue_map(struct blk_mq_reg *reg);
extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues);
void blk_mq_add_timer(struct request *rq);

88
drivers/block/null_blk.c
View File

@ -32,6 +32,7 @@ struct nullb {
unsigned int index;
struct request_queue *q;
struct gendisk *disk;
struct blk_mq_tag_set tag_set;
struct hrtimer timer;
unsigned int queue_depth;
spinlock_t lock;
@ -320,10 +321,11 @@ static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq)
return BLK_MQ_RQ_QUEUE_OK;
}
static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_reg *reg, unsigned int hctx_index)
static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_tag_set *set,
unsigned int 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 b_size = DIV_ROUND_UP(set->nr_hw_queues, nr_online_nodes);
int tip = (set->nr_hw_queues % nr_online_nodes);
int node = 0, i, n;
/*
@ -338,7 +340,7 @@ static struct blk_mq_hw_ctx *null_alloc_hctx(struct blk_mq_reg *reg, unsigned in
tip--;
if (!tip)
b_size = reg->nr_hw_queues / nr_online_nodes;
b_size = set->nr_hw_queues / nr_online_nodes;
}
}
@ -387,13 +389,17 @@ static struct blk_mq_ops null_mq_ops = {
.map_queue = blk_mq_map_queue,
.init_hctx = null_init_hctx,
.complete = null_softirq_done_fn,
.alloc_hctx = blk_mq_alloc_single_hw_queue,
.free_hctx = blk_mq_free_single_hw_queue,
};
static struct blk_mq_reg null_mq_reg = {
.ops = &null_mq_ops,
.queue_depth = 64,
.cmd_size = sizeof(struct nullb_cmd),
.flags = BLK_MQ_F_SHOULD_MERGE,
static struct blk_mq_ops null_mq_ops_pernode = {
.queue_rq = null_queue_rq,
.map_queue = blk_mq_map_queue,
.init_hctx = null_init_hctx,
.complete = null_softirq_done_fn,
.alloc_hctx = null_alloc_hctx,
.free_hctx = null_free_hctx,
};
static void null_del_dev(struct nullb *nullb)
@ -402,6 +408,8 @@ static void null_del_dev(struct nullb *nullb)
del_gendisk(nullb->disk);
blk_cleanup_queue(nullb->q);
if (queue_mode == NULL_Q_MQ)
blk_mq_free_tag_set(&nullb->tag_set);
put_disk(nullb->disk);
kfree(nullb);
}
@ -506,7 +514,7 @@ static int null_add_dev(void)
nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, home_node);
if (!nullb)
return -ENOMEM;
goto out;
spin_lock_init(&nullb->lock);
@ -514,49 +522,47 @@ static int null_add_dev(void)
submit_queues = nr_online_nodes;
if (setup_queues(nullb))
goto err;
goto out_free_nullb;
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)
nullb->tag_set.ops = &null_mq_ops_pernode;
else
nullb->tag_set.ops = &null_mq_ops;
nullb->tag_set.nr_hw_queues = submit_queues;
nullb->tag_set.queue_depth = hw_queue_depth;
nullb->tag_set.numa_node = home_node;
nullb->tag_set.cmd_size = sizeof(struct nullb_cmd);
nullb->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
nullb->tag_set.driver_data = nullb;
if (use_per_node_hctx) {
null_mq_reg.ops->alloc_hctx = null_alloc_hctx;
null_mq_reg.ops->free_hctx = null_free_hctx;
} 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;
}
if (blk_mq_alloc_tag_set(&nullb->tag_set))
goto out_cleanup_queues;
nullb->q = blk_mq_init_queue(&null_mq_reg, nullb);
nullb->q = blk_mq_init_queue(&nullb->tag_set);
if (!nullb->q)
goto out_cleanup_tags;
} else if (queue_mode == NULL_Q_BIO) {
nullb->q = blk_alloc_queue_node(GFP_KERNEL, home_node);
if (!nullb->q)
goto out_cleanup_queues;
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);
if (!nullb->q)
goto out_cleanup_queues;
blk_queue_prep_rq(nullb->q, null_rq_prep_fn);
if (nullb->q)
blk_queue_softirq_done(nullb->q, null_softirq_done_fn);
blk_queue_softirq_done(nullb->q, null_softirq_done_fn);
init_driver_queues(nullb);
}
if (!nullb->q)
goto queue_fail;
nullb->q->queuedata = nullb;
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, nullb->q);
disk = nullb->disk = alloc_disk_node(1, home_node);
if (!disk) {
queue_fail:
blk_cleanup_queue(nullb->q);
cleanup_queues(nullb);
err:
kfree(nullb);
return -ENOMEM;
}
if (!disk)
goto out_cleanup_blk_queue;
mutex_lock(&lock);
list_add_tail(&nullb->list, &nullb_list);
@ -579,6 +585,18 @@ err:
sprintf(disk->disk_name, "nullb%d", nullb->index);
add_disk(disk);
return 0;
out_cleanup_blk_queue:
blk_cleanup_queue(nullb->q);
out_cleanup_tags:
if (queue_mode == NULL_Q_MQ)
blk_mq_free_tag_set(&nullb->tag_set);
out_cleanup_queues:
cleanup_queues(nullb);
out_free_nullb:
kfree(nullb);
out:
return -ENOMEM;
}
static int __init null_init(void)

48
drivers/block/virtio_blk.c
View File

@ -30,6 +30,9 @@ struct virtio_blk
/* The disk structure for the kernel. */
struct gendisk *disk;
/* Block layer tags. */
struct blk_mq_tag_set tag_set;
/* Process context for config space updates */
struct work_struct config_work;
@ -480,8 +483,9 @@ static const struct device_attribute dev_attr_cache_type_rw =
__ATTR(cache_type, S_IRUGO|S_IWUSR,
virtblk_cache_type_show, virtblk_cache_type_store);
static int virtblk_init_request(void *data, struct blk_mq_hw_ctx *hctx,
struct request *rq, unsigned int nr)
static int virtblk_init_request(void *data, struct request *rq,
unsigned int hctx_idx, unsigned int request_idx,
unsigned int numa_node)
{
struct virtio_blk *vblk = data;
struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
@ -495,18 +499,12 @@ static struct blk_mq_ops virtio_mq_ops = {
.map_queue = blk_mq_map_queue,
.alloc_hctx = blk_mq_alloc_single_hw_queue,
.free_hctx = blk_mq_free_single_hw_queue,
.init_request = virtblk_init_request,
.complete = virtblk_request_done,
.init_request = virtblk_init_request,
};
static struct blk_mq_reg virtio_mq_reg = {
.ops = &virtio_mq_ops,
.nr_hw_queues = 1,
.queue_depth = 0, /* Set in virtblk_probe */
.numa_node = NUMA_NO_NODE,
.flags = BLK_MQ_F_SHOULD_MERGE,
};
module_param_named(queue_depth, virtio_mq_reg.queue_depth, uint, 0444);
static unsigned int virtblk_queue_depth;
module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
static int virtblk_probe(struct virtio_device *vdev)
{
@ -562,20 +560,32 @@ static int virtblk_probe(struct virtio_device *vdev)
}
/* Default queue sizing is to fill the ring. */
if (!virtio_mq_reg.queue_depth) {
virtio_mq_reg.queue_depth = vblk->vq->num_free;
if (!virtblk_queue_depth) {
virtblk_queue_depth = vblk->vq->num_free;
/* ... but without indirect descs, we use 2 descs per req */
if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
virtio_mq_reg.queue_depth /= 2;
virtblk_queue_depth /= 2;
}
virtio_mq_reg.cmd_size =
memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
vblk->tag_set.ops = &virtio_mq_ops;
vblk->tag_set.nr_hw_queues = 1;
vblk->tag_set.queue_depth = virtblk_queue_depth;
vblk->tag_set.numa_node = NUMA_NO_NODE;
vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
vblk->tag_set.cmd_size =
sizeof(struct virtblk_req) +
sizeof(struct scatterlist) * sg_elems;
vblk->tag_set.driver_data = vblk;
q = vblk->disk->queue = blk_mq_init_queue(&virtio_mq_reg, vblk);
err = blk_mq_alloc_tag_set(&vblk->tag_set);
if (err)
goto out_put_disk;
q = vblk->disk->queue = blk_mq_init_queue(&vblk->tag_set);
if (!q) {
err = -ENOMEM;
goto out_put_disk;
goto out_free_tags;
}
q->queuedata = vblk;
@ -678,6 +688,8 @@ static int virtblk_probe(struct virtio_device *vdev)
out_del_disk:
del_gendisk(vblk->disk);
blk_cleanup_queue(vblk->disk->queue);
out_free_tags:
blk_mq_free_tag_set(&vblk->tag_set);
out_put_disk:
put_disk(vblk->disk);
out_free_vq:
@ -704,6 +716,8 @@ static void virtblk_remove(struct virtio_device *vdev)
del_gendisk(vblk->disk);
blk_cleanup_queue(vblk->disk->queue);
blk_mq_free_tag_set(&vblk->tag_set);
/* Stop all the virtqueues. */
vdev->config->reset(vdev);

34
include/linux/blk-mq.h
View File

@ -33,8 +33,6 @@ struct blk_mq_hw_ctx {
unsigned int nr_ctx_map;
unsigned long *ctx_map;
struct request **rqs;
struct list_head page_list;
struct blk_mq_tags *tags;
unsigned long queued;
@ -42,7 +40,6 @@ struct blk_mq_hw_ctx {
#define BLK_MQ_MAX_DISPATCH_ORDER 10
unsigned long dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
unsigned int queue_depth;
unsigned int numa_node;
unsigned int cmd_size; /* per-request extra data */
@ -50,7 +47,7 @@ struct blk_mq_hw_ctx {
struct kobject kobj;
};
struct blk_mq_reg {
struct blk_mq_tag_set {
struct blk_mq_ops *ops;
unsigned int nr_hw_queues;
unsigned int queue_depth;
@ -59,18 +56,22 @@ struct blk_mq_reg {
int numa_node;
unsigned int timeout;
unsigned int flags; /* BLK_MQ_F_* */
void *driver_data;
struct blk_mq_tags **tags;
};
typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *);
typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
typedef struct blk_mq_hw_ctx *(alloc_hctx_fn)(struct blk_mq_reg *,unsigned int);
typedef struct blk_mq_hw_ctx *(alloc_hctx_fn)(struct blk_mq_tag_set *,
unsigned int);
typedef void (free_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
typedef int (init_request_fn)(void *, struct blk_mq_hw_ctx *,
struct request *, unsigned int);
typedef void (exit_request_fn)(void *, struct blk_mq_hw_ctx *,
struct request *, unsigned int);
typedef int (init_request_fn)(void *, struct request *, unsigned int,
unsigned int, unsigned int);
typedef void (exit_request_fn)(void *, struct request *, unsigned int,
unsigned int);
struct blk_mq_ops {
/*
@ -127,10 +128,13 @@ enum {
BLK_MQ_MAX_DEPTH = 2048,
};
struct request_queue *blk_mq_init_queue(struct blk_mq_reg *, void *);
struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
int blk_mq_register_disk(struct gendisk *);
void blk_mq_unregister_disk(struct gendisk *);
int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
void blk_mq_insert_request(struct request *, bool, bool, bool);
@ -139,10 +143,10 @@ void blk_mq_free_request(struct request *rq);
bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp);
struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, gfp_t gfp);
struct request *blk_mq_rq_from_tag(struct request_queue *q, unsigned int tag);
struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_reg *, unsigned int);
struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int);
void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx *, unsigned int);
bool blk_mq_end_io_partial(struct request *rq, int error,
@ -173,12 +177,6 @@ static inline void *blk_mq_rq_to_pdu(struct request *rq)
return (void *) rq + sizeof(*rq);
}
static inline struct request *blk_mq_tag_to_rq(struct blk_mq_hw_ctx *hctx,
unsigned int tag)
{
return hctx->rqs[tag];
}
#define queue_for_each_hw_ctx(q, hctx, i) \
for ((i) = 0; (i) < (q)->nr_hw_queues && \
({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)