[PATCH v4 13/13] blk-mq: Stop using pointers for blk_mq_tags bitmap tags

From: John Garry
Date: Fri Sep 24 2021 - 04:34:31 EST


Now that we use shared tags for shared sbitmap support, we don't require
the tags sbitmap pointers, so drop them.

This essentially reverts commit 222a5ae03cdd ("blk-mq: Use pointers for
blk_mq_tags bitmap tags").

Function blk_mq_init_bitmap_tags() is removed also, since it would be only
a wrappper for blk_mq_init_bitmaps().

Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
block/bfq-iosched.c | 4 +--
block/blk-mq-debugfs.c | 8 +++---
block/blk-mq-tag.c | 56 +++++++++++++++---------------------------
block/blk-mq-tag.h | 7 ++----
block/blk-mq.c | 8 +++---
block/kyber-iosched.c | 4 +--
block/mq-deadline.c | 2 +-
7 files changed, 35 insertions(+), 54 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index dd13c2bbc29c..4674f85d7df0 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -6894,8 +6894,8 @@ static void bfq_depth_updated(struct blk_mq_hw_ctx *hctx)
struct blk_mq_tags *tags = hctx->sched_tags;
unsigned int min_shallow;

- min_shallow = bfq_update_depths(bfqd, tags->bitmap_tags);
- sbitmap_queue_min_shallow_depth(tags->bitmap_tags, min_shallow);
+ min_shallow = bfq_update_depths(bfqd, &tags->bitmap_tags);
+ sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, min_shallow);
}

static int bfq_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int index)
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 4b66d2776eda..4000376330c9 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -452,11 +452,11 @@ static void blk_mq_debugfs_tags_show(struct seq_file *m,
atomic_read(&tags->active_queues));

seq_puts(m, "\nbitmap_tags:\n");
- sbitmap_queue_show(tags->bitmap_tags, m);
+ sbitmap_queue_show(&tags->bitmap_tags, m);

if (tags->nr_reserved_tags) {
seq_puts(m, "\nbreserved_tags:\n");
- sbitmap_queue_show(tags->breserved_tags, m);
+ sbitmap_queue_show(&tags->breserved_tags, m);
}
}

@@ -487,7 +487,7 @@ static int hctx_tags_bitmap_show(void *data, struct seq_file *m)
if (res)
goto out;
if (hctx->tags)
- sbitmap_bitmap_show(&hctx->tags->bitmap_tags->sb, m);
+ sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);
mutex_unlock(&q->sysfs_lock);

out:
@@ -521,7 +521,7 @@ static int hctx_sched_tags_bitmap_show(void *data, struct seq_file *m)
if (res)
goto out;
if (hctx->sched_tags)
- sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags->sb, m);
+ sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);
mutex_unlock(&q->sysfs_lock);

out:
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 4e71ce6b37ea..4cf0f74f4fa9 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -46,9 +46,9 @@ bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
*/
void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve)
{
- sbitmap_queue_wake_all(tags->bitmap_tags);
+ sbitmap_queue_wake_all(&tags->bitmap_tags);
if (include_reserve)
- sbitmap_queue_wake_all(tags->breserved_tags);
+ sbitmap_queue_wake_all(&tags->breserved_tags);
}

/*
@@ -104,10 +104,10 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
WARN_ON_ONCE(1);
return BLK_MQ_NO_TAG;
}
- bt = tags->breserved_tags;
+ bt = &tags->breserved_tags;
tag_offset = 0;
} else {
- bt = tags->bitmap_tags;
+ bt = &tags->bitmap_tags;
tag_offset = tags->nr_reserved_tags;
}

@@ -153,9 +153,9 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
data->ctx);
tags = blk_mq_tags_from_data(data);
if (data->flags & BLK_MQ_REQ_RESERVED)
- bt = tags->breserved_tags;
+ bt = &tags->breserved_tags;
else
- bt = tags->bitmap_tags;
+ bt = &tags->bitmap_tags;

/*
* If destination hw queue is changed, fake wake up on
@@ -189,10 +189,10 @@ void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx,
const int real_tag = tag - tags->nr_reserved_tags;

BUG_ON(real_tag >= tags->nr_tags);
- sbitmap_queue_clear(tags->bitmap_tags, real_tag, ctx->cpu);
+ sbitmap_queue_clear(&tags->bitmap_tags, real_tag, ctx->cpu);
} else {
BUG_ON(tag >= tags->nr_reserved_tags);
- sbitmap_queue_clear(tags->breserved_tags, tag, ctx->cpu);
+ sbitmap_queue_clear(&tags->breserved_tags, tag, ctx->cpu);
}
}

@@ -343,9 +343,9 @@ static void __blk_mq_all_tag_iter(struct blk_mq_tags *tags,
WARN_ON_ONCE(flags & BT_TAG_ITER_RESERVED);

if (tags->nr_reserved_tags)
- bt_tags_for_each(tags, tags->breserved_tags, fn, priv,
+ bt_tags_for_each(tags, &tags->breserved_tags, fn, priv,
flags | BT_TAG_ITER_RESERVED);
- bt_tags_for_each(tags, tags->bitmap_tags, fn, priv, flags);
+ bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, flags);
}

/**
@@ -462,8 +462,8 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
continue;

if (tags->nr_reserved_tags)
- bt_for_each(hctx, tags->breserved_tags, fn, priv, true);
- bt_for_each(hctx, tags->bitmap_tags, fn, priv, false);
+ bt_for_each(hctx, &tags->breserved_tags, fn, priv, true);
+ bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false);
}
blk_queue_exit(q);
}
@@ -495,24 +495,6 @@ int blk_mq_init_bitmaps(struct sbitmap_queue *bitmap_tags,
return -ENOMEM;
}

-static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
- int node, int alloc_policy)
-{
- int ret;
-
- ret = blk_mq_init_bitmaps(&tags->__bitmap_tags,
- &tags->__breserved_tags,
- tags->nr_tags, tags->nr_reserved_tags,
- node, alloc_policy);
- if (ret)
- return ret;
-
- tags->bitmap_tags = &tags->__bitmap_tags;
- tags->breserved_tags = &tags->__breserved_tags;
-
- return 0;
-}
-
struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
unsigned int reserved_tags,
int node, int alloc_policy)
@@ -532,7 +514,9 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
tags->nr_reserved_tags = reserved_tags;
spin_lock_init(&tags->lock);

- if (blk_mq_init_bitmap_tags(tags, node, alloc_policy) < 0) {
+ if (blk_mq_init_bitmaps(&tags->bitmap_tags, &tags->breserved_tags,
+ total_tags, reserved_tags, node,
+ alloc_policy) < 0) {
kfree(tags);
return NULL;
}
@@ -541,8 +525,8 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,

void blk_mq_free_tags(struct blk_mq_tags *tags)
{
- sbitmap_queue_free(tags->bitmap_tags);
- sbitmap_queue_free(tags->breserved_tags);
+ sbitmap_queue_free(&tags->bitmap_tags);
+ sbitmap_queue_free(&tags->breserved_tags);
kfree(tags);
}

@@ -591,7 +575,7 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
* Don't need (or can't) update reserved tags here, they
* remain static and should never need resizing.
*/
- sbitmap_queue_resize(tags->bitmap_tags,
+ sbitmap_queue_resize(&tags->bitmap_tags,
tdepth - tags->nr_reserved_tags);
}

@@ -602,12 +586,12 @@ void blk_mq_tag_resize_shared_sbitmap(struct blk_mq_tag_set *set, unsigned int s
{
struct blk_mq_tags *tags = set->shared_sbitmap_tags;

- sbitmap_queue_resize(&tags->__bitmap_tags, size - set->reserved_tags);
+ sbitmap_queue_resize(&tags->bitmap_tags, size - set->reserved_tags);
}

void blk_mq_tag_update_sched_shared_sbitmap(struct request_queue *q)
{
- sbitmap_queue_resize(q->shared_sbitmap_tags->bitmap_tags,
+ sbitmap_queue_resize(&q->shared_sbitmap_tags->bitmap_tags,
q->nr_requests - q->tag_set->reserved_tags);
}

diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index e433e39a9cfa..23747ea2bb53 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -11,11 +11,8 @@ struct blk_mq_tags {

atomic_t active_queues;

- struct sbitmap_queue *bitmap_tags;
- struct sbitmap_queue *breserved_tags;
-
- struct sbitmap_queue __bitmap_tags;
- struct sbitmap_queue __breserved_tags;
+ struct sbitmap_queue bitmap_tags;
+ struct sbitmap_queue breserved_tags;

struct request **rqs;
struct request **static_rqs;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index ece43855bcdf..5baa35cae8a0 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1062,14 +1062,14 @@ static inline unsigned int queued_to_index(unsigned int queued)

static bool __blk_mq_get_driver_tag(struct request *rq)
{
- struct sbitmap_queue *bt = rq->mq_hctx->tags->bitmap_tags;
+ struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags;
unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags;
int tag;

blk_mq_tag_busy(rq->mq_hctx);

if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) {
- bt = rq->mq_hctx->tags->breserved_tags;
+ bt = &rq->mq_hctx->tags->breserved_tags;
tag_offset = 0;
} else {
if (!hctx_may_queue(rq->mq_hctx, bt))
@@ -1112,7 +1112,7 @@ static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,
struct sbitmap_queue *sbq;

list_del_init(&wait->entry);
- sbq = hctx->tags->bitmap_tags;
+ sbq = &hctx->tags->bitmap_tags;
atomic_dec(&sbq->ws_active);
}
spin_unlock(&hctx->dispatch_wait_lock);
@@ -1130,7 +1130,7 @@ static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,
static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx,
struct request *rq)
{
- struct sbitmap_queue *sbq = hctx->tags->bitmap_tags;
+ struct sbitmap_queue *sbq = &hctx->tags->bitmap_tags;
struct wait_queue_head *wq;
wait_queue_entry_t *wait;
bool ret;
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index 15a8be57203d..9fb735bf1134 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -451,11 +451,11 @@ static void kyber_depth_updated(struct blk_mq_hw_ctx *hctx)
{
struct kyber_queue_data *kqd = hctx->queue->elevator->elevator_data;
struct blk_mq_tags *tags = hctx->sched_tags;
- unsigned int shift = tags->bitmap_tags->sb.shift;
+ unsigned int shift = tags->bitmap_tags.sb.shift;

kqd->async_depth = (1U << shift) * KYBER_ASYNC_PERCENT / 100U;

- sbitmap_queue_min_shallow_depth(tags->bitmap_tags, kqd->async_depth);
+ sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, kqd->async_depth);
}

static int kyber_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index 7f3c3932b723..7fd07d00838e 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -519,7 +519,7 @@ static void dd_depth_updated(struct blk_mq_hw_ctx *hctx)

dd->async_depth = max(1UL, 3 * q->nr_requests / 4);

- sbitmap_queue_min_shallow_depth(tags->bitmap_tags, dd->async_depth);
+ sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, dd->async_depth);
}

/* Called by blk_mq_init_hctx() and blk_mq_init_sched(). */
--
2.26.2