2020-08-26 02:19:26

by Tianxianting

[permalink] [raw]
Subject: [PATCH] [v2] blk-mq: use BLK_MQ_NO_TAG for no tag

Replace various magic -1 constants for tags with BLK_MQ_NO_TAG.
And move the definition of BLK_MQ_NO_TAG from 'block/blk-mq-tag.h'
to 'include/linux/blk-mq.h'

Signed-off-by: Xianting Tian <[email protected]>
---
block/blk-core.c | 4 ++--
block/blk-mq-sched.c | 2 +-
block/blk-mq-tag.h | 6 ------
include/linux/blk-mq.h | 8 +++++++-
4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index d9d632639..c7eaf7504 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -116,8 +116,8 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
rq->__sector = (sector_t) -1;
INIT_HLIST_NODE(&rq->hash);
RB_CLEAR_NODE(&rq->rb_node);
- rq->tag = -1;
- rq->internal_tag = -1;
+ rq->tag = BLK_MQ_NO_TAG;
+ rq->internal_tag = BLK_MQ_NO_TAG;
rq->start_time_ns = ktime_get_ns();
rq->part = NULL;
refcount_set(&rq->ref, 1);
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index a19cdf159..439481f59 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -522,7 +522,7 @@ void blk_mq_sched_insert_request(struct request *rq, bool at_head,
goto run;
}

- WARN_ON(e && (rq->tag != -1));
+ WARN_ON(e && (rq->tag != BLK_MQ_NO_TAG));

if (blk_mq_sched_bypass_insert(hctx, !!e, rq)) {
/*
diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index b1acac518..8fc48aa72 100644
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -45,12 +45,6 @@ static inline struct sbq_wait_state *bt_wait_ptr(struct sbitmap_queue *bt,
return sbq_wait_ptr(bt, &hctx->wait_index);
}

-enum {
- BLK_MQ_NO_TAG = -1U,
- BLK_MQ_TAG_MIN = 1,
- BLK_MQ_TAG_MAX = BLK_MQ_NO_TAG - 1,
-};
-
extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 9d2d5ad36..2499d8aae 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -209,6 +209,12 @@ enum hctx_type {
HCTX_MAX_TYPES,
};

+enum {
+ BLK_MQ_NO_TAG = -1U,
+ BLK_MQ_TAG_MIN = 1,
+ BLK_MQ_TAG_MAX = BLK_MQ_NO_TAG - 1,
+};
+
/**
* struct blk_mq_tag_set - tag set that can be shared between request queues
* @map: One or more ctx -> hctx mappings. One map exists for each
@@ -569,7 +575,7 @@ static inline void *blk_mq_rq_to_pdu(struct request *rq)
static inline blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx,
struct request *rq)
{
- if (rq->tag != -1)
+ if (rq->tag != BLK_MQ_NO_TAG)
return rq->tag | (hctx->queue_num << BLK_QC_T_SHIFT);

return rq->internal_tag | (hctx->queue_num << BLK_QC_T_SHIFT) |
--
2.17.1


2020-08-26 04:30:47

by Ming Lei

[permalink] [raw]
Subject: Re: [PATCH] [v2] blk-mq: use BLK_MQ_NO_TAG for no tag

On Wed, Aug 26, 2020 at 10:06:51AM +0800, Xianting Tian wrote:
> Replace various magic -1 constants for tags with BLK_MQ_NO_TAG.
> And move the definition of BLK_MQ_NO_TAG from 'block/blk-mq-tag.h'
> to 'include/linux/blk-mq.h'

All three symbols are supposed for block core internal code only, so
looks you shouldn't move them to public header.


Thanks,
Ming

2020-08-26 07:56:08

by Tianxianting

[permalink] [raw]
Subject: RE: [PATCH] [v2] blk-mq: use BLK_MQ_NO_TAG for no tag

Hi Ming Lei
Thanks for your quick comment.
As the function request_to_qc_t() in 'include/linux/blk-mq.h ' used the magic '-1',
Seems it is hard to replace it with BLK_MQ_NO_TAG :(

-----Original Message-----
From: Ming Lei [mailto:[email protected]]
Sent: Wednesday, August 26, 2020 12:29 PM
To: tianxianting (RD) <[email protected]>
Cc: [email protected]; [email protected]; [email protected]
Subject: Re: [PATCH] [v2] blk-mq: use BLK_MQ_NO_TAG for no tag

On Wed, Aug 26, 2020 at 10:06:51AM +0800, Xianting Tian wrote:
> Replace various magic -1 constants for tags with BLK_MQ_NO_TAG.
> And move the definition of BLK_MQ_NO_TAG from 'block/blk-mq-tag.h'
> to 'include/linux/blk-mq.h'

All three symbols are supposed for block core internal code only, so looks you shouldn't move them to public header.


Thanks,
Ming