linux-imx

/*

 * Copyright (C) 2012 Red Hat. All rights reserved.

 *

 * This file is released under the GPL.

 */

​

#include "dm.h"

#include "dm-bio-prison-v2.h"

#include "dm-bio-record.h"

#include "dm-cache-metadata.h"

​

#include <linux/dm-io.h>

#include <linux/dm-kcopyd.h>

#include <linux/jiffies.h>

#include <linux/init.h>

#include <linux/mempool.h>

#include <linux/module.h>

#include <linux/rwsem.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>

​

#define DM_MSG_PREFIX "cache"

​

DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(cache_copy_throttle,

    "A percentage of time allocated for copying to and/or from cache");

​

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

​

/*

 * Glossary:

 *

 * oblock: index of an origin block

 * cblock: index of a cache block

 * promotion: movement of a block from origin to cache

 * demotion: movement of a block from cache to origin

 * migration: movement of a block between the origin and cache device,

 *        either direction

 */

​

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

​

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;