Commit ce32496e authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: simplify tag allocation policy selection 



Use a plain BLK_MQ_F_* flag to select the round robin tag selection
instead of overlaying an enum with just two possible values into the
flags space.

Doing so allows adding a BLK_MQ_F_MAX sentinel for simplified overflow
checking in the messy debugfs helpers.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJohn Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20250106083531.799976-5-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e7602bb4

block/blk-mq-debugfs.c

+4 −21
Original line number Diff line number Diff line
@@ -172,19 +172,13 @@ static int hctx_state_show(void *data, struct seq_file *m) 
	return 0;

}



#define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name

static const char *const alloc_policy_name[] = {

	BLK_TAG_ALLOC_NAME(FIFO),

	BLK_TAG_ALLOC_NAME(RR),

};

#undef BLK_TAG_ALLOC_NAME



#define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name

static const char *const hctx_flag_name[] = {

	HCTX_FLAG_NAME(TAG_QUEUE_SHARED),

	HCTX_FLAG_NAME(STACKING),

	HCTX_FLAG_NAME(TAG_HCTX_SHARED),

	HCTX_FLAG_NAME(BLOCKING),

	HCTX_FLAG_NAME(TAG_RR),

	HCTX_FLAG_NAME(NO_SCHED_BY_DEFAULT),

};

#undef HCTX_FLAG_NAME
@@ -192,22 +186,11 @@ static const char *const hctx_flag_name[] = { 
static int hctx_flags_show(void *data, struct seq_file *m)

{

	struct blk_mq_hw_ctx *hctx = data;

	const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);



	BUILD_BUG_ON(ARRAY_SIZE(hctx_flag_name) !=

			BLK_MQ_F_ALLOC_POLICY_START_BIT);

	BUILD_BUG_ON(ARRAY_SIZE(alloc_policy_name) != BLK_TAG_ALLOC_MAX);

	BUILD_BUG_ON(ARRAY_SIZE(hctx_flag_name) != ilog2(BLK_MQ_F_MAX));



	seq_puts(m, "alloc_policy=");

	if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&

	    alloc_policy_name[alloc_policy])

		seq_puts(m, alloc_policy_name[alloc_policy]);

	else

		seq_printf(m, "%d", alloc_policy);

	seq_puts(m, " ");

	blk_flags_show(m,

		       hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),

		       hctx_flag_name, ARRAY_SIZE(hctx_flag_name));

	blk_flags_show(m, hctx->flags, hctx_flag_name,

			ARRAY_SIZE(hctx_flag_name));

	seq_puts(m, "\n");

	return 0;

}

block/blk-mq-tag.c

+2 −3
Original line number Diff line number Diff line
@@ -545,11 +545,10 @@ static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth, 
}



struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,

				     unsigned int reserved_tags,

				     int node, int alloc_policy)

		unsigned int reserved_tags, unsigned int flags, int node)

{

	unsigned int depth = total_tags - reserved_tags;

	bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR;

	bool round_robin = flags & BLK_MQ_F_TAG_RR;

	struct blk_mq_tags *tags;



	if (total_tags > BLK_MQ_TAG_MAX) {

block/blk-mq.c

+1 −2
Original line number Diff line number Diff line
@@ -3476,8 +3476,7 @@ static struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, 
	if (node == NUMA_NO_NODE)

		node = set->numa_node;



	tags = blk_mq_init_tags(nr_tags, reserved_tags, node,

				BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags));

	tags = blk_mq_init_tags(nr_tags, reserved_tags, set->flags, node);

	if (!tags)

		return NULL;

block/blk-mq.h

+1 −1
Original line number Diff line number Diff line
@@ -163,7 +163,7 @@ struct blk_mq_alloc_data { 
};



struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags,

		unsigned int reserved_tags, int node, int alloc_policy);

		unsigned int reserved_tags, unsigned int flags, int node);

void blk_mq_free_tags(struct blk_mq_tags *tags);



unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);

drivers/ata/ahci.h

+1 −1
Original line number Diff line number Diff line
@@ -396,7 +396,7 @@ extern const struct attribute_group *ahci_sdev_groups[]; 
	.shost_groups		= ahci_shost_groups,			\

	.sdev_groups		= ahci_sdev_groups,			\

	.change_queue_depth     = ata_scsi_change_queue_depth,		\

	.tag_alloc_policy       = BLK_TAG_ALLOC_RR,             	\

	.tag_alloc_policy_rr	= true,					\

	.device_configure	= ata_scsi_device_configure



extern struct ata_port_operations ahci_ops;