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Commit d332ce09 authored by Omar Sandoval's avatar Omar Sandoval Committed by Jens Axboe
Browse files

blk-mq-debugfs: allow schedulers to register debugfs attributes 



This provides the infrastructure for schedulers to expose their internal
state through debugfs. We add a list of queue attributes and a list of
hctx attributes to struct elevator_type and wire them up when switching
schedulers.

Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>

Add missing seq_file.h header in blk-mq-debugfs.h

Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 9c1051aa

block/blk-mq-debugfs.c

+65 −9
Original line number Diff line number Diff line
@@ -24,15 +24,6 @@ 
#include "blk-mq-debugfs.h"

#include "blk-mq-tag.h"



struct blk_mq_debugfs_attr {

	const char *name;

	umode_t mode;

	int (*show)(void *, struct seq_file *);

	ssize_t (*write)(void *, const char __user *, size_t, loff_t *);

	/* Set either .show or .seq_ops. */

	const struct seq_operations *seq_ops;

};



static int blk_flags_show(struct seq_file *m, const unsigned long flags,

			  const char *const *flag_name, int flag_name_count)

{
@@ -725,6 +716,9 @@ int blk_mq_debugfs_register(struct request_queue *q) 
	queue_for_each_hw_ctx(q, hctx, i) {

		if (!hctx->debugfs_dir && blk_mq_debugfs_register_hctx(q, hctx))

			goto err;

		if (q->elevator && !hctx->sched_debugfs_dir &&

		    blk_mq_debugfs_register_sched_hctx(q, hctx))

			goto err;

	}



	return 0;
@@ -737,6 +731,7 @@ int blk_mq_debugfs_register(struct request_queue *q) 
void blk_mq_debugfs_unregister(struct request_queue *q)

{

	debugfs_remove_recursive(q->debugfs_dir);

	q->sched_debugfs_dir = NULL;

	q->debugfs_dir = NULL;

}
@@ -791,6 +786,7 @@ int blk_mq_debugfs_register_hctx(struct request_queue *q, 
void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)

{

	debugfs_remove_recursive(hctx->debugfs_dir);

	hctx->sched_debugfs_dir = NULL;

	hctx->debugfs_dir = NULL;

}
@@ -815,3 +811,63 @@ void blk_mq_debugfs_unregister_hctxs(struct request_queue *q) 
	queue_for_each_hw_ctx(q, hctx, i)

		blk_mq_debugfs_unregister_hctx(hctx);

}



int blk_mq_debugfs_register_sched(struct request_queue *q)

{

	struct elevator_type *e = q->elevator->type;



	if (!q->debugfs_dir)

		return -ENOENT;



	if (!e->queue_debugfs_attrs)

		return 0;



	q->sched_debugfs_dir = debugfs_create_dir("sched", q->debugfs_dir);

	if (!q->sched_debugfs_dir)

		return -ENOMEM;



	if (!debugfs_create_files(q->sched_debugfs_dir, q,

				  e->queue_debugfs_attrs))

		goto err;



	return 0;



err:

	blk_mq_debugfs_unregister_sched(q);

	return -ENOMEM;

}



void blk_mq_debugfs_unregister_sched(struct request_queue *q)

{

	debugfs_remove_recursive(q->sched_debugfs_dir);

	q->sched_debugfs_dir = NULL;

}



int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,

				       struct blk_mq_hw_ctx *hctx)

{

	struct elevator_type *e = q->elevator->type;



	if (!hctx->debugfs_dir)

		return -ENOENT;



	if (!e->hctx_debugfs_attrs)

		return 0;



	hctx->sched_debugfs_dir = debugfs_create_dir("sched",

						     hctx->debugfs_dir);

	if (!hctx->sched_debugfs_dir)

		return -ENOMEM;



	if (!debugfs_create_files(hctx->sched_debugfs_dir, hctx,

				  e->hctx_debugfs_attrs))

		return -ENOMEM;



	return 0;

}



void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)

{

	debugfs_remove_recursive(hctx->sched_debugfs_dir);

	hctx->sched_debugfs_dir = NULL;

}

block/blk-mq-debugfs.h

+37 −0
Original line number Diff line number Diff line
@@ -2,6 +2,18 @@ 
#define INT_BLK_MQ_DEBUGFS_H



#ifdef CONFIG_BLK_DEBUG_FS



#include <linux/seq_file.h>



struct blk_mq_debugfs_attr {

	const char *name;

	umode_t mode;

	int (*show)(void *, struct seq_file *);

	ssize_t (*write)(void *, const char __user *, size_t, loff_t *);

	/* Set either .show or .seq_ops. */

	const struct seq_operations *seq_ops;

};



int blk_mq_debugfs_register(struct request_queue *q);

void blk_mq_debugfs_unregister(struct request_queue *q);

int blk_mq_debugfs_register_hctx(struct request_queue *q,
@@ -9,6 +21,12 @@ int blk_mq_debugfs_register_hctx(struct request_queue *q, 
void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx);

int blk_mq_debugfs_register_hctxs(struct request_queue *q);

void blk_mq_debugfs_unregister_hctxs(struct request_queue *q);



int blk_mq_debugfs_register_sched(struct request_queue *q);

void blk_mq_debugfs_unregister_sched(struct request_queue *q);

int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,

				       struct blk_mq_hw_ctx *hctx);

void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);

#else

static inline int blk_mq_debugfs_register(struct request_queue *q)

{
@@ -37,6 +55,25 @@ static inline int blk_mq_debugfs_register_hctxs(struct request_queue *q) 
static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)

{

}



static inline int blk_mq_debugfs_register_sched(struct request_queue *q)

{

	return 0;

}



static inline void blk_mq_debugfs_unregister_sched(struct request_queue *q)

{

}



static inline int blk_mq_debugfs_register_sched_hctx(struct request_queue *q,

						     struct blk_mq_hw_ctx *hctx)

{

	return 0;

}



static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)

{

}

#endif



#endif

block/blk-mq-sched.c

+16 −8
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 


#include "blk.h"

#include "blk-mq.h"

#include "blk-mq-debugfs.h"

#include "blk-mq-sched.h"

#include "blk-mq-tag.h"

#include "blk-wbt.h"
@@ -472,6 +473,8 @@ int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, 
		}

	}



	blk_mq_debugfs_register_sched_hctx(q, hctx);



	return 0;

}
@@ -483,6 +486,8 @@ void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, 
	if (!e)

		return;



	blk_mq_debugfs_unregister_sched_hctx(hctx);



	if (e->type->ops.mq.exit_hctx && hctx->sched_data) {

		e->type->ops.mq.exit_hctx(hctx, hctx_idx);

		hctx->sched_data = NULL;
@@ -519,8 +524,10 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) 
	if (ret)

		goto err;



	if (e->ops.mq.init_hctx) {

	blk_mq_debugfs_register_sched(q);



	queue_for_each_hw_ctx(q, hctx, i) {

		if (e->ops.mq.init_hctx) {

			ret = e->ops.mq.init_hctx(hctx, i);

			if (ret) {

				eq = q->elevator;
@@ -529,6 +536,7 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) 
				return ret;

			}

		}

		blk_mq_debugfs_register_sched_hctx(q, hctx);

	}



	return 0;
@@ -544,14 +552,14 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e) 
	struct blk_mq_hw_ctx *hctx;

	unsigned int i;



	if (e->type->ops.mq.exit_hctx) {

	queue_for_each_hw_ctx(q, hctx, i) {

			if (hctx->sched_data) {

		blk_mq_debugfs_unregister_sched_hctx(hctx);

		if (e->type->ops.mq.exit_hctx && hctx->sched_data) {

			e->type->ops.mq.exit_hctx(hctx, i);

			hctx->sched_data = NULL;

		}

	}

	}

	blk_mq_debugfs_unregister_sched(q);

	if (e->type->ops.mq.exit_sched)

		e->type->ops.mq.exit_sched(e);

	blk_mq_sched_tags_teardown(q);

include/linux/blk-mq.h

+1 −0
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ struct blk_mq_hw_ctx { 


#ifdef CONFIG_BLK_DEBUG_FS

	struct dentry		*debugfs_dir;

	struct dentry		*sched_debugfs_dir;

#endif

};

include/linux/blkdev.h

+1 −0
Original line number Diff line number Diff line
@@ -579,6 +579,7 @@ struct request_queue { 


#ifdef CONFIG_BLK_DEBUG_FS

	struct dentry		*debugfs_dir;

	struct dentry		*sched_debugfs_dir;

#endif



	bool			mq_sysfs_init_done;