Commit dc4fa29f authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm io tracker: factor out IO tracker 



Allow other code to use dm_io_tracker.

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent b6e58b54

drivers/md/dm-cache-target.c

+6 −76
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include "dm-bio-prison-v2.h"

#include "dm-bio-record.h"

#include "dm-cache-metadata.h"

#include "dm-io-tracker.h"



#include <linux/dm-io.h>

#include <linux/dm-kcopyd.h>
@@ -39,77 +40,6 @@ DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(cache_copy_throttle, 


/*----------------------------------------------------------------*/



struct io_tracker {

	spinlock_t lock;



	/*

	 * Sectors of in-flight IO.

	 */

	sector_t in_flight;



	/*

	 * The time, in jiffies, when this device became idle (if it is

	 * indeed idle).

	 */

	unsigned long idle_time;

	unsigned long last_update_time;

};



static void iot_init(struct io_tracker *iot)

{

	spin_lock_init(&iot->lock);

	iot->in_flight = 0ul;

	iot->idle_time = 0ul;

	iot->last_update_time = jiffies;

}



static bool __iot_idle_for(struct io_tracker *iot, unsigned long jifs)

{

	if (iot->in_flight)

		return false;



	return time_after(jiffies, iot->idle_time + jifs);

}



static bool iot_idle_for(struct io_tracker *iot, unsigned long jifs)

{

	bool r;



	spin_lock_irq(&iot->lock);

	r = __iot_idle_for(iot, jifs);

	spin_unlock_irq(&iot->lock);



	return r;

}



static void iot_io_begin(struct io_tracker *iot, sector_t len)

{

	spin_lock_irq(&iot->lock);

	iot->in_flight += len;

	spin_unlock_irq(&iot->lock);

}



static void __iot_io_end(struct io_tracker *iot, sector_t len)

{

	if (!len)

		return;



	iot->in_flight -= len;

	if (!iot->in_flight)

		iot->idle_time = jiffies;

}



static void iot_io_end(struct io_tracker *iot, sector_t len)

{

	unsigned long flags;



	spin_lock_irqsave(&iot->lock, flags);

	__iot_io_end(iot, len);

	spin_unlock_irqrestore(&iot->lock, flags);

}



/*----------------------------------------------------------------*/



/*

 * Represents a chunk of future work.  'input' allows continuations to pass

 * values between themselves, typically error values.
@@ -470,7 +400,7 @@ struct cache { 
	struct batcher committer;

	struct work_struct commit_ws;



	struct io_tracker tracker;

	struct dm_io_tracker tracker;



	mempool_t migration_pool;
@@ -866,7 +796,7 @@ static void accounted_begin(struct cache *cache, struct bio *bio) 
	if (accountable_bio(cache, bio)) {

		pb = get_per_bio_data(bio);

		pb->len = bio_sectors(bio);

		iot_io_begin(&cache->tracker, pb->len);

		dm_iot_io_begin(&cache->tracker, pb->len);

	}

}
@@ -874,7 +804,7 @@ static void accounted_complete(struct cache *cache, struct bio *bio) 
{

	struct per_bio_data *pb = get_per_bio_data(bio);



	iot_io_end(&cache->tracker, pb->len);

	dm_iot_io_end(&cache->tracker, pb->len);

}



static void accounted_request(struct cache *cache, struct bio *bio)
@@ -1642,7 +1572,7 @@ enum busy { 


static enum busy spare_migration_bandwidth(struct cache *cache)

{

	bool idle = iot_idle_for(&cache->tracker, HZ);

	bool idle = dm_iot_idle_for(&cache->tracker, HZ);

	sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) *

		cache->sectors_per_block;
@@ -2603,7 +2533,7 @@ static int cache_create(struct cache_args *ca, struct cache **result) 


	batcher_init(&cache->committer, commit_op, cache,

		     issue_op, cache, cache->wq);

	iot_init(&cache->tracker);

	dm_iot_init(&cache->tracker);



	init_rwsem(&cache->background_work_lock);

	prevent_background_work(cache);

drivers/md/dm-io-tracker.h

0 → 100644
+69 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2021 Red Hat, Inc. All rights reserved.

 *

 * This file is released under the GPL.

 */



#ifndef DM_IO_TRACKER_H

#define DM_IO_TRACKER_H



#include <linux/jiffies.h>



struct dm_io_tracker {

	spinlock_t lock;



	/*

	 * Sectors of in-flight IO.

	 */

	sector_t in_flight;



	/*

	 * The time, in jiffies, when this device became idle

	 * (if it is indeed idle).

	 */

	unsigned long idle_time;

	unsigned long last_update_time;

};



static inline void dm_iot_init(struct dm_io_tracker *iot)

{

	spin_lock_init(&iot->lock);

	iot->in_flight = 0ul;

	iot->idle_time = 0ul;

	iot->last_update_time = jiffies;

}



static inline bool dm_iot_idle_for(struct dm_io_tracker *iot, unsigned long j)

{

	bool r = false;



	spin_lock_irq(&iot->lock);

	if (!iot->in_flight)

		r = time_after(jiffies, iot->idle_time + j);

	spin_unlock_irq(&iot->lock);



	return r;

}



static inline void dm_iot_io_begin(struct dm_io_tracker *iot, sector_t len)

{

	spin_lock_irq(&iot->lock);

	iot->in_flight += len;

	spin_unlock_irq(&iot->lock);

}



static inline void dm_iot_io_end(struct dm_io_tracker *iot, sector_t len)

{

	unsigned long flags;



	if (!len)

		return;



	spin_lock_irqsave(&iot->lock, flags);

	iot->in_flight -= len;

	if (!iot->in_flight)

		iot->idle_time = jiffies;

	spin_unlock_irqrestore(&iot->lock, flags);

}



#endif