Commit cc56694f authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

blk-mq-debugfs: support rq_qos 



blk-mq-debugfs has been proved as very helpful for debug some
tough issues, such as IO hang.

We have seen blk-wbt related IO hang several times, even inside
Red Hat BZ, there is such report not sovled yet, so this patch
adds support debugfs on rq_qos.

Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f9824952

block/blk-mq-debugfs.c

+54 −0
Original line number Original line Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include "blk-mq.h"

#include "blk-mq.h"

#include "blk-mq-debugfs.h"

#include "blk-mq-debugfs.h"

#include "blk-mq-tag.h"

#include "blk-mq-tag.h"

#include "blk-rq-qos.h"





static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)

static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)

{

{
@@ -856,6 +857,15 @@ int blk_mq_debugfs_register(struct request_queue *q) 
			goto err;

			goto err;

	}

	}





	if (q->rq_qos) {

		struct rq_qos *rqos = q->rq_qos;



		while (rqos) {

			blk_mq_debugfs_register_rqos(rqos);

			rqos = rqos->next;

		}

	}



	return 0;

	return 0;





err:

err:
@@ -978,6 +988,50 @@ void blk_mq_debugfs_unregister_sched(struct request_queue *q) 
	q->sched_debugfs_dir = NULL;

	q->sched_debugfs_dir = NULL;

}

}





void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)

{

	debugfs_remove_recursive(rqos->debugfs_dir);

	rqos->debugfs_dir = NULL;

}



int blk_mq_debugfs_register_rqos(struct rq_qos *rqos)

{

	struct request_queue *q = rqos->q;

	const char *dir_name = rq_qos_id_to_name(rqos->id);



	if (!q->debugfs_dir)

		return -ENOENT;



	if (rqos->debugfs_dir || !rqos->ops->debugfs_attrs)

		return 0;



	if (!q->rqos_debugfs_dir) {

		q->rqos_debugfs_dir = debugfs_create_dir("rqos",

							 q->debugfs_dir);

		if (!q->rqos_debugfs_dir)

			return -ENOMEM;

	}



	rqos->debugfs_dir = debugfs_create_dir(dir_name,

					       rqos->q->rqos_debugfs_dir);

	if (!rqos->debugfs_dir)

		return -ENOMEM;



	if (!debugfs_create_files(rqos->debugfs_dir, rqos,

				  rqos->ops->debugfs_attrs))

		goto err;

	return 0;

 err:

	blk_mq_debugfs_unregister_rqos(rqos);

	return -ENOMEM;

}



void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)

{

	debugfs_remove_recursive(q->rqos_debugfs_dir);

	q->rqos_debugfs_dir = NULL;

}



int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,

int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,

				       struct blk_mq_hw_ctx *hctx)

				       struct blk_mq_hw_ctx *hctx)

{

{

block/blk-mq-debugfs.h

+17 −0
Original line number Original line Diff line number Diff line
@@ -31,6 +31,10 @@ void blk_mq_debugfs_unregister_sched(struct request_queue *q); 
int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,

int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,

				       struct blk_mq_hw_ctx *hctx);

				       struct blk_mq_hw_ctx *hctx);

void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);

void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);



int blk_mq_debugfs_register_rqos(struct rq_qos *rqos);

void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos);

void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q);

#else

#else

static inline int blk_mq_debugfs_register(struct request_queue *q)

static inline int blk_mq_debugfs_register(struct request_queue *q)

{

{
@@ -78,6 +82,19 @@ static inline int blk_mq_debugfs_register_sched_hctx(struct request_queue *q, 
static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)

static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)

{

{

}

}



static inline int blk_mq_debugfs_register_rqos(struct rq_qos *rqos)

{

	return 0;

}



static inline void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)

{

}



static inline void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)

{

}

#endif

#endif





#ifdef CONFIG_BLK_DEBUG_FS_ZONED

#ifdef CONFIG_BLK_DEBUG_FS_ZONED

block/blk-rq-qos.c

+2 −0
Original line number Original line Diff line number Diff line
@@ -264,6 +264,8 @@ void rq_qos_wait(struct rq_wait *rqw, void *private_data, 




void rq_qos_exit(struct request_queue *q)

void rq_qos_exit(struct request_queue *q)

{

{

	blk_mq_debugfs_unregister_queue_rqos(q);



	while (q->rq_qos) {

	while (q->rq_qos) {

		struct rq_qos *rqos = q->rq_qos;

		struct rq_qos *rqos = q->rq_qos;

		q->rq_qos = rqos->next;

		q->rq_qos = rqos->next;

block/blk-rq-qos.h

+24 −0
Original line number Original line Diff line number Diff line
@@ -7,6 +7,10 @@ 
#include <linux/atomic.h>

#include <linux/atomic.h>

#include <linux/wait.h>

#include <linux/wait.h>





#include "blk-mq-debugfs.h"



struct blk_mq_debugfs_attr;



enum rq_qos_id {

enum rq_qos_id {

	RQ_QOS_WBT,

	RQ_QOS_WBT,

	RQ_QOS_CGROUP,

	RQ_QOS_CGROUP,
@@ -22,6 +26,9 @@ struct rq_qos { 
	struct request_queue *q;

	struct request_queue *q;

	enum rq_qos_id id;

	enum rq_qos_id id;

	struct rq_qos *next;

	struct rq_qos *next;

#ifdef CONFIG_BLK_DEBUG_FS

	struct dentry *debugfs_dir;

#endif

};

};





struct rq_qos_ops {

struct rq_qos_ops {
@@ -33,6 +40,7 @@ struct rq_qos_ops { 
	void (*done_bio)(struct rq_qos *, struct bio *);

	void (*done_bio)(struct rq_qos *, struct bio *);

	void (*cleanup)(struct rq_qos *, struct bio *);

	void (*cleanup)(struct rq_qos *, struct bio *);

	void (*exit)(struct rq_qos *);

	void (*exit)(struct rq_qos *);

	const struct blk_mq_debugfs_attr *debugfs_attrs;

};

};





struct rq_depth {

struct rq_depth {
@@ -66,6 +74,17 @@ static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q) 
	return rq_qos_id(q, RQ_QOS_CGROUP);

	return rq_qos_id(q, RQ_QOS_CGROUP);

}

}





static inline const char *rq_qos_id_to_name(enum rq_qos_id id)

{

	switch (id) {

	case RQ_QOS_WBT:

		return "wbt";

	case RQ_QOS_CGROUP:

		return "cgroup";

	}

	return "unknown";

}



static inline void rq_wait_init(struct rq_wait *rq_wait)

static inline void rq_wait_init(struct rq_wait *rq_wait)

{

{

	atomic_set(&rq_wait->inflight, 0);

	atomic_set(&rq_wait->inflight, 0);
@@ -76,6 +95,9 @@ static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos) 
{

{

	rqos->next = q->rq_qos;

	rqos->next = q->rq_qos;

	q->rq_qos = rqos;

	q->rq_qos = rqos;



	if (rqos->ops->debugfs_attrs)

		blk_mq_debugfs_register_rqos(rqos);

}

}





static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)

static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
@@ -91,6 +113,8 @@ static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos) 
		}

		}

		prev = cur;

		prev = cur;

	}

	}



	blk_mq_debugfs_unregister_rqos(rqos);

}

}





typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);

typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);

include/linux/blkdev.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -560,6 +560,7 @@ struct request_queue { 
#ifdef CONFIG_BLK_DEBUG_FS

#ifdef CONFIG_BLK_DEBUG_FS

	struct dentry		*debugfs_dir;

	struct dentry		*debugfs_dir;

	struct dentry		*sched_debugfs_dir;

	struct dentry		*sched_debugfs_dir;

	struct dentry		*rqos_debugfs_dir;

#endif

#endif





	bool			mq_sysfs_init_done;

	bool			mq_sysfs_init_done;

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