[PATCH v8 05/18] blk-mq: Use pointers for blk_mq_tags bitmap tags

John Garry
2020-08-19T15:25:51Z

Introduce pointers for the blk_mq_tags regular and reserved bitmap tags,
with the goal of later being able to use a common shared tag bitmap across
all HW contexts in a set.

Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.garry@huawei.com>
---
block/bfq-iosched.c | 4 ++--
block/blk-mq-debugfs.c | 8 ++++----
block/blk-mq-tag.c | 41 ++++++++++++++++++++++-------------------
block/blk-mq-tag.h | 7 +++++--
block/blk-mq.c | 8 ++++----
block/kyber-iosched.c | 4 ++--
6 files changed, 39 insertions(+), 33 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index a4c0bec920cb..88f0dfa545d7 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -6372,8 +6372,8 @@ 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 a4597febff69..645b7f800cb8 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 0426f01e06a6..77fbeae05745 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -35,9 +35,9 @@ 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);
}

/*
@@ -82,10 +82,10 @@ 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;
}

@@ -131,9 +131,9 @@ 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
@@ -167,10 +167,10 @@ 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);
}
}

@@ -298,9 +298,9 @@ 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);
}

/**
@@ -416,8 +416,8 @@ 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);
}
@@ -435,15 +435,18 @@ static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
unsigned int depth = tags->nr_tags - tags->nr_reserved_tags;
bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR;

- if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node))
+ if (bt_alloc(&tags->__bitmap_tags, depth, round_robin, node))
return -ENOMEM;
- if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin,
- node))
+ if (bt_alloc(&tags->__breserved_tags, tags->nr_reserved_tags,
+ round_robin, node))
goto free_bitmap_tags;

+ tags->bitmap_tags = &tags->__bitmap_tags;
+ tags->breserved_tags = &tags->__breserved_tags;
+
return 0;
free_bitmap_tags:
- sbitmap_queue_free(&tags->bitmap_tags);
+ sbitmap_queue_free(&tags->__bitmap_tags);
return -ENOMEM;
}

@@ -475,8 +478,8 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,

void blk_mq_free_tags(struct blk_mq_tags *tags, unsigned int flags)
{
- 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);
}

@@ -527,7 +530,7 @@ 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);
}

diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index 391f68d32fa1..5b6f25bd1966 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -13,8 +13,11 @@ 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 376930061452..ce712ec818e4 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1096,14 +1096,14 @@ 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;
}

@@ -1145,7 +1145,7 @@ 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);
@@ -1163,7 +1163,7 @@ 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 a38c5ab103d1..075e99c207ef 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -359,7 +359,7 @@ static unsigned int kyber_sched_tags_shift(struct request_queue *q)
* All of the hardware queues have the same depth, so we can just grab
* the shift of the first one.
*/
- return q->queue_hw_ctx[0]->sched_tags->bitmap_tags.sb.shift;
+ return q->queue_hw_ctx[0]->sched_tags->bitmap_tags->sb.shift;
}

static struct kyber_queue_data *kyber_queue_data_alloc(struct request_queue *q)
@@ -502,7 +502,7 @@ static int kyber_init_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
khd->batching = 0;

hctx->sched_data = khd;
- sbitmap_queue_min_shallow_depth(&hctx->sched_tags->bitmap_tags,
+ sbitmap_queue_min_shallow_depth(hctx->sched_tags->bitmap_tags,
kqd->async_depth);

return 0;
--
2.26.2