Merge branch 'cfq-merge' of git://brick.kernel.dk/data/git/linux-2.6-block

* 'cfq-merge' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [BLOCK] cfq-iosched: seek and async performance fixes
  [PATCH] ll_rw_blk: fix 80-col offender in put_io_context()
  [PATCH] cfq-iosched: small cfq_choose_req() optimization
  [PATCH] [BLOCK] cfq-iosched: change cfq io context linking from list to tree
This commit is contained in:
Linus Torvalds 2006-03-28 09:25:44 -08:00
commit 7baf398f12
3 changed files with 222 additions and 182 deletions

View file

@ -26,18 +26,12 @@ static const int cfq_back_penalty = 2; /* penalty of a backwards seek */
static const int cfq_slice_sync = HZ / 10;
static int cfq_slice_async = HZ / 25;
static const int cfq_slice_async_rq = 2;
static int cfq_slice_idle = HZ / 100;
static int cfq_slice_idle = HZ / 70;
#define CFQ_IDLE_GRACE (HZ / 10)
#define CFQ_SLICE_SCALE (5)
#define CFQ_KEY_ASYNC (0)
#define CFQ_KEY_ANY (0xffff)
/*
* disable queueing at the driver/hardware level
*/
static const int cfq_max_depth = 2;
static DEFINE_RWLOCK(cfq_exit_lock);
@ -102,6 +96,8 @@ static struct completion *ioc_gone;
#define cfq_cfqq_sync(cfqq) \
(cfq_cfqq_class_sync(cfqq) || (cfqq)->on_dispatch[SYNC])
#define sample_valid(samples) ((samples) > 80)
/*
* Per block device queue structure
*/
@ -170,7 +166,6 @@ struct cfq_data {
unsigned int cfq_slice[2];
unsigned int cfq_slice_async_rq;
unsigned int cfq_slice_idle;
unsigned int cfq_max_depth;
struct list_head cic_list;
};
@ -343,17 +338,27 @@ static int cfq_queue_empty(request_queue_t *q)
return !cfqd->busy_queues;
}
static inline pid_t cfq_queue_pid(struct task_struct *task, int rw)
{
if (rw == READ || process_sync(task))
return task->pid;
return CFQ_KEY_ASYNC;
}
/*
* Lifted from AS - choose which of crq1 and crq2 that is best served now.
* We choose the request that is closest to the head right now. Distance
* behind the head are penalized and only allowed to a certain extent.
* behind the head is penalized and only allowed to a certain extent.
*/
static struct cfq_rq *
cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2)
{
sector_t last, s1, s2, d1 = 0, d2 = 0;
int r1_wrap = 0, r2_wrap = 0; /* requests are behind the disk head */
unsigned long back_max;
#define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */
#define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */
unsigned wrap = 0; /* bit mask: requests behind the disk head? */
if (crq1 == NULL || crq1 == crq2)
return crq2;
@ -385,35 +390,47 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2)
else if (s1 + back_max >= last)
d1 = (last - s1) * cfqd->cfq_back_penalty;
else
r1_wrap = 1;
wrap |= CFQ_RQ1_WRAP;
if (s2 >= last)
d2 = s2 - last;
else if (s2 + back_max >= last)
d2 = (last - s2) * cfqd->cfq_back_penalty;
else
r2_wrap = 1;
wrap |= CFQ_RQ2_WRAP;
/* Found required data */
if (!r1_wrap && r2_wrap)
return crq1;
else if (!r2_wrap && r1_wrap)
return crq2;
else if (r1_wrap && r2_wrap) {
/* both behind the head */
if (s1 <= s2)
return crq1;
else
return crq2;
}
/* Both requests in front of the head */
if (d1 < d2)
/*
* By doing switch() on the bit mask "wrap" we avoid having to
* check two variables for all permutations: --> faster!
*/
switch (wrap) {
case 0: /* common case for CFQ: crq1 and crq2 not wrapped */
if (d1 < d2)
return crq1;
else if (d2 < d1)
return crq2;
else {
if (s1 >= s2)
return crq1;
else
return crq2;
}
case CFQ_RQ2_WRAP:
return crq1;
else if (d2 < d1)
case CFQ_RQ1_WRAP:
return crq2;
else {
if (s1 >= s2)
case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both crqs wrapped */
default:
/*
* Since both rqs are wrapped,
* start with the one that's further behind head
* (--> only *one* back seek required),
* since back seek takes more time than forward.
*/
if (s1 <= s2)
return crq1;
else
return crq2;
@ -612,15 +629,20 @@ cfq_reposition_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
cfq_add_crq_rb(crq);
}
static struct request *cfq_find_rq_rb(struct cfq_data *cfqd, sector_t sector)
static struct request *
cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
{
struct cfq_queue *cfqq = cfq_find_cfq_hash(cfqd, current->pid, CFQ_KEY_ANY);
struct task_struct *tsk = current;
pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio));
struct cfq_queue *cfqq;
struct rb_node *n;
sector_t sector;
cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio);
if (!cfqq)
goto out;
sector = bio->bi_sector + bio_sectors(bio);
n = cfqq->sort_list.rb_node;
while (n) {
struct cfq_rq *crq = rb_entry_crq(n);
@ -674,7 +696,7 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio)
goto out;
}
__rq = cfq_find_rq_rb(cfqd, bio->bi_sector + bio_sectors(bio));
__rq = cfq_find_rq_fmerge(cfqd, bio);
if (__rq && elv_rq_merge_ok(__rq, bio)) {
ret = ELEVATOR_FRONT_MERGE;
goto out;
@ -877,6 +899,7 @@ static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd)
static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
struct cfq_io_context *cic;
unsigned long sl;
WARN_ON(!RB_EMPTY(&cfqq->sort_list));
@ -892,13 +915,23 @@ static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
/*
* task has exited, don't wait
*/
if (cfqd->active_cic && !cfqd->active_cic->ioc->task)
cic = cfqd->active_cic;
if (!cic || !cic->ioc->task)
return 0;
cfq_mark_cfqq_must_dispatch(cfqq);
cfq_mark_cfqq_wait_request(cfqq);
sl = min(cfqq->slice_end - 1, (unsigned long) cfqd->cfq_slice_idle);
/*
* we don't want to idle for seeks, but we do want to allow
* fair distribution of slice time for a process doing back-to-back
* seeks. so allow a little bit of time for him to submit a new rq
*/
if (sample_valid(cic->seek_samples) && cic->seek_mean > 131072)
sl = 2;
mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
return 1;
}
@ -1115,13 +1148,6 @@ cfq_dispatch_requests(request_queue_t *q, int force)
if (cfqq) {
int max_dispatch;
/*
* if idle window is disabled, allow queue buildup
*/
if (!cfq_cfqq_idle_window(cfqq) &&
cfqd->rq_in_driver >= cfqd->cfq_max_depth)
return 0;
cfq_clear_cfqq_must_dispatch(cfqq);
cfq_clear_cfqq_wait_request(cfqq);
del_timer(&cfqd->idle_slice_timer);
@ -1171,13 +1197,13 @@ __cfq_find_cfq_hash(struct cfq_data *cfqd, unsigned int key, unsigned int prio,
const int hashval)
{
struct hlist_head *hash_list = &cfqd->cfq_hash[hashval];
struct hlist_node *entry, *next;
struct hlist_node *entry;
struct cfq_queue *__cfqq;
hlist_for_each_safe(entry, next, hash_list) {
struct cfq_queue *__cfqq = list_entry_qhash(entry);
hlist_for_each_entry(__cfqq, entry, hash_list, cfq_hash) {
const unsigned short __p = IOPRIO_PRIO_VALUE(__cfqq->org_ioprio_class, __cfqq->org_ioprio);
if (__cfqq->key == key && (__p == prio || prio == CFQ_KEY_ANY))
if (__cfqq->key == key && (__p == prio || !prio))
return __cfqq;
}
@ -1190,19 +1216,19 @@ cfq_find_cfq_hash(struct cfq_data *cfqd, unsigned int key, unsigned short prio)
return __cfq_find_cfq_hash(cfqd, key, prio, hash_long(key, CFQ_QHASH_SHIFT));
}
static void cfq_free_io_context(struct cfq_io_context *cic)
static void cfq_free_io_context(struct io_context *ioc)
{
struct cfq_io_context *__cic;
struct list_head *entry, *next;
int freed = 1;
struct rb_node *n;
int freed = 0;
list_for_each_safe(entry, next, &cic->list) {
__cic = list_entry(entry, struct cfq_io_context, list);
while ((n = rb_first(&ioc->cic_root)) != NULL) {
__cic = rb_entry(n, struct cfq_io_context, rb_node);
rb_erase(&__cic->rb_node, &ioc->cic_root);
kmem_cache_free(cfq_ioc_pool, __cic);
freed++;
}
kmem_cache_free(cfq_ioc_pool, cic);
if (atomic_sub_and_test(freed, &ioc_count) && ioc_gone)
complete(ioc_gone);
}
@ -1210,8 +1236,7 @@ static void cfq_free_io_context(struct cfq_io_context *cic)
static void cfq_trim(struct io_context *ioc)
{
ioc->set_ioprio = NULL;
if (ioc->cic)
cfq_free_io_context(ioc->cic);
cfq_free_io_context(ioc);
}
/*
@ -1250,26 +1275,26 @@ static void cfq_exit_single_io_context(struct cfq_io_context *cic)
spin_unlock(q->queue_lock);
}
static void cfq_exit_io_context(struct cfq_io_context *cic)
static void cfq_exit_io_context(struct io_context *ioc)
{
struct cfq_io_context *__cic;
struct list_head *entry;
unsigned long flags;
local_irq_save(flags);
struct rb_node *n;
/*
* put the reference this task is holding to the various queues
*/
read_lock(&cfq_exit_lock);
list_for_each(entry, &cic->list) {
__cic = list_entry(entry, struct cfq_io_context, list);
read_lock_irqsave(&cfq_exit_lock, flags);
n = rb_first(&ioc->cic_root);
while (n != NULL) {
__cic = rb_entry(n, struct cfq_io_context, rb_node);
cfq_exit_single_io_context(__cic);
n = rb_next(n);
}
cfq_exit_single_io_context(cic);
read_unlock(&cfq_exit_lock);
local_irq_restore(flags);
read_unlock_irqrestore(&cfq_exit_lock, flags);
}
static struct cfq_io_context *
@ -1278,10 +1303,10 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
struct cfq_io_context *cic = kmem_cache_alloc(cfq_ioc_pool, gfp_mask);
if (cic) {
INIT_LIST_HEAD(&cic->list);
RB_CLEAR(&cic->rb_node);
cic->key = NULL;
cic->cfqq[ASYNC] = NULL;
cic->cfqq[SYNC] = NULL;
cic->key = NULL;
cic->last_end_request = jiffies;
cic->ttime_total = 0;
cic->ttime_samples = 0;
@ -1373,15 +1398,17 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio)
{
struct cfq_io_context *cic;
struct rb_node *n;
write_lock(&cfq_exit_lock);
cic = ioc->cic;
n = rb_first(&ioc->cic_root);
while (n != NULL) {
cic = rb_entry(n, struct cfq_io_context, rb_node);
changed_ioprio(cic);
list_for_each_entry(cic, &cic->list, list)
changed_ioprio(cic);
n = rb_next(n);
}
write_unlock(&cfq_exit_lock);
@ -1445,14 +1472,67 @@ cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk,
return cfqq;
}
static struct cfq_io_context *
cfq_cic_rb_lookup(struct cfq_data *cfqd, struct io_context *ioc)
{
struct rb_node *n = ioc->cic_root.rb_node;
struct cfq_io_context *cic;
void *key = cfqd;
while (n) {
cic = rb_entry(n, struct cfq_io_context, rb_node);
if (key < cic->key)
n = n->rb_left;
else if (key > cic->key)
n = n->rb_right;
else
return cic;
}
return NULL;
}
static inline void
cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc,
struct cfq_io_context *cic)
{
struct rb_node **p = &ioc->cic_root.rb_node;
struct rb_node *parent = NULL;
struct cfq_io_context *__cic;
read_lock(&cfq_exit_lock);
cic->ioc = ioc;
cic->key = cfqd;
ioc->set_ioprio = cfq_ioc_set_ioprio;
while (*p) {
parent = *p;
__cic = rb_entry(parent, struct cfq_io_context, rb_node);
if (cic->key < __cic->key)
p = &(*p)->rb_left;
else if (cic->key > __cic->key)
p = &(*p)->rb_right;
else
BUG();
}
rb_link_node(&cic->rb_node, parent, p);
rb_insert_color(&cic->rb_node, &ioc->cic_root);
list_add(&cic->queue_list, &cfqd->cic_list);
read_unlock(&cfq_exit_lock);
}
/*
* Setup general io context and cfq io context. There can be several cfq
* io contexts per general io context, if this process is doing io to more
* than one device managed by cfq. Note that caller is holding a reference to
* cfqq, so we don't need to worry about it disappearing
* than one device managed by cfq.
*/
static struct cfq_io_context *
cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask)
cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
{
struct io_context *ioc = NULL;
struct cfq_io_context *cic;
@ -1463,88 +1543,15 @@ cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask)
if (!ioc)
return NULL;
restart:
if ((cic = ioc->cic) == NULL) {
cic = cfq_alloc_io_context(cfqd, gfp_mask);
cic = cfq_cic_rb_lookup(cfqd, ioc);
if (cic)
goto out;
if (cic == NULL)
goto err;
/*
* manually increment generic io_context usage count, it
* cannot go away since we are already holding one ref to it
*/
cic->ioc = ioc;
cic->key = cfqd;
read_lock(&cfq_exit_lock);
ioc->set_ioprio = cfq_ioc_set_ioprio;
ioc->cic = cic;
list_add(&cic->queue_list, &cfqd->cic_list);
read_unlock(&cfq_exit_lock);
} else {
struct cfq_io_context *__cic;
/*
* the first cic on the list is actually the head itself
*/
if (cic->key == cfqd)
goto out;
if (unlikely(!cic->key)) {
read_lock(&cfq_exit_lock);
if (list_empty(&cic->list))
ioc->cic = NULL;
else
ioc->cic = list_entry(cic->list.next,
struct cfq_io_context,
list);
read_unlock(&cfq_exit_lock);
kmem_cache_free(cfq_ioc_pool, cic);
atomic_dec(&ioc_count);
goto restart;
}
/*
* cic exists, check if we already are there. linear search
* should be ok here, the list will usually not be more than
* 1 or a few entries long
*/
list_for_each_entry(__cic, &cic->list, list) {
/*
* this process is already holding a reference to
* this queue, so no need to get one more
*/
if (__cic->key == cfqd) {
cic = __cic;
goto out;
}
if (unlikely(!__cic->key)) {
read_lock(&cfq_exit_lock);
list_del(&__cic->list);
read_unlock(&cfq_exit_lock);
kmem_cache_free(cfq_ioc_pool, __cic);
atomic_dec(&ioc_count);
goto restart;
}
}
/*
* nope, process doesn't have a cic assoicated with this
* cfqq yet. get a new one and add to list
*/
__cic = cfq_alloc_io_context(cfqd, gfp_mask);
if (__cic == NULL)
goto err;
__cic->ioc = ioc;
__cic->key = cfqd;
read_lock(&cfq_exit_lock);
list_add(&__cic->list, &cic->list);
list_add(&__cic->queue_list, &cfqd->cic_list);
read_unlock(&cfq_exit_lock);
cic = __cic;
}
cic = cfq_alloc_io_context(cfqd, gfp_mask);
if (cic == NULL)
goto err;
cfq_cic_link(cfqd, ioc, cic);
out:
return cic;
err:
@ -1577,7 +1584,33 @@ cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic)
cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples;
}
#define sample_valid(samples) ((samples) > 80)
static void
cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic,
struct cfq_rq *crq)
{
sector_t sdist;
u64 total;
if (cic->last_request_pos < crq->request->sector)
sdist = crq->request->sector - cic->last_request_pos;
else
sdist = cic->last_request_pos - crq->request->sector;
/*
* Don't allow the seek distance to get too large from the
* odd fragment, pagein, etc
*/
if (cic->seek_samples <= 60) /* second&third seek */
sdist = min(sdist, (cic->seek_mean * 4) + 2*1024*1024);
else
sdist = min(sdist, (cic->seek_mean * 4) + 2*1024*64);
cic->seek_samples = (7*cic->seek_samples + 256) / 8;
cic->seek_total = (7*cic->seek_total + (u64)256*sdist) / 8;
total = cic->seek_total + (cic->seek_samples/2);
do_div(total, cic->seek_samples);
cic->seek_mean = (sector_t)total;
}
/*
* Disable idle window if the process thinks too long or seeks so much that
@ -1690,9 +1723,11 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
cic = crq->io_context;
cfq_update_io_thinktime(cfqd, cic);
cfq_update_io_seektime(cfqd, cic, crq);
cfq_update_idle_window(cfqd, cfqq, cic);
cic->last_queue = jiffies;
cic->last_request_pos = crq->request->sector + crq->request->nr_sectors;
if (cfqq == cfqd->active_queue) {
/*
@ -1825,14 +1860,6 @@ static void cfq_prio_boost(struct cfq_queue *cfqq)
cfq_resort_rr_list(cfqq, 0);
}
static inline pid_t cfq_queue_pid(struct task_struct *task, int rw)
{
if (rw == READ || process_sync(task))
return task->pid;
return CFQ_KEY_ASYNC;
}
static inline int
__cfq_may_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq,
struct task_struct *task, int rw)
@ -1965,7 +1992,7 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
might_sleep_if(gfp_mask & __GFP_WAIT);
cic = cfq_get_io_context(cfqd, key, gfp_mask);
cic = cfq_get_io_context(cfqd, gfp_mask);
spin_lock_irqsave(q->queue_lock, flags);
@ -2133,11 +2160,14 @@ static void cfq_exit_queue(elevator_t *e)
request_queue_t *q = cfqd->queue;
cfq_shutdown_timer_wq(cfqd);
write_lock(&cfq_exit_lock);
spin_lock_irq(q->queue_lock);
if (cfqd->active_queue)
__cfq_slice_expired(cfqd, cfqd->active_queue, 0);
while(!list_empty(&cfqd->cic_list)) {
while (!list_empty(&cfqd->cic_list)) {
struct cfq_io_context *cic = list_entry(cfqd->cic_list.next,
struct cfq_io_context,
queue_list);
@ -2152,6 +2182,7 @@ static void cfq_exit_queue(elevator_t *e)
cic->key = NULL;
list_del_init(&cic->queue_list);
}
spin_unlock_irq(q->queue_lock);
write_unlock(&cfq_exit_lock);
@ -2227,7 +2258,6 @@ static int cfq_init_queue(request_queue_t *q, elevator_t *e)
cfqd->cfq_slice[1] = cfq_slice_sync;
cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
cfqd->cfq_slice_idle = cfq_slice_idle;
cfqd->cfq_max_depth = cfq_max_depth;
return 0;
out_crqpool:
@ -2310,7 +2340,6 @@ SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1);
SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1);
SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1);
SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0);
SHOW_FUNCTION(cfq_max_depth_show, cfqd->cfq_max_depth, 0);
#undef SHOW_FUNCTION
#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
@ -2339,7 +2368,6 @@ STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1);
STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1);
STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1);
STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, UINT_MAX, 0);
STORE_FUNCTION(cfq_max_depth_store, &cfqd->cfq_max_depth, 1, UINT_MAX, 0);
#undef STORE_FUNCTION
#define CFQ_ATTR(name) \
@ -2356,7 +2384,6 @@ static struct elv_fs_entry cfq_attrs[] = {
CFQ_ATTR(slice_async),
CFQ_ATTR(slice_async_rq),
CFQ_ATTR(slice_idle),
CFQ_ATTR(max_depth),
__ATTR_NULL
};

View file

@ -3539,11 +3539,17 @@ void put_io_context(struct io_context *ioc)
BUG_ON(atomic_read(&ioc->refcount) == 0);
if (atomic_dec_and_test(&ioc->refcount)) {
struct cfq_io_context *cic;
rcu_read_lock();
if (ioc->aic && ioc->aic->dtor)
ioc->aic->dtor(ioc->aic);
if (ioc->cic && ioc->cic->dtor)
ioc->cic->dtor(ioc->cic);
if (ioc->cic_root.rb_node != NULL) {
struct rb_node *n = rb_first(&ioc->cic_root);
cic = rb_entry(n, struct cfq_io_context, rb_node);
cic->dtor(ioc);
}
rcu_read_unlock();
kmem_cache_free(iocontext_cachep, ioc);
@ -3556,6 +3562,7 @@ void exit_io_context(void)
{
unsigned long flags;
struct io_context *ioc;
struct cfq_io_context *cic;
local_irq_save(flags);
task_lock(current);
@ -3567,8 +3574,10 @@ void exit_io_context(void)
if (ioc->aic && ioc->aic->exit)
ioc->aic->exit(ioc->aic);
if (ioc->cic && ioc->cic->exit)
ioc->cic->exit(ioc->cic);
if (ioc->cic_root.rb_node != NULL) {
cic = rb_entry(rb_first(&ioc->cic_root), struct cfq_io_context, rb_node);
cic->exit(ioc);
}
put_io_context(ioc);
}
@ -3598,7 +3607,7 @@ struct io_context *current_io_context(gfp_t gfp_flags)
ret->last_waited = jiffies; /* doesn't matter... */
ret->nr_batch_requests = 0; /* because this is 0 */
ret->aic = NULL;
ret->cic = NULL;
ret->cic_root.rb_node = NULL;
tsk->io_context = ret;
}

View file

@ -55,25 +55,29 @@ struct as_io_context {
struct cfq_queue;
struct cfq_io_context {
/*
* circular list of cfq_io_contexts belonging to a process io context
*/
struct list_head list;
struct cfq_queue *cfqq[2];
struct rb_node rb_node;
void *key;
struct cfq_queue *cfqq[2];
struct io_context *ioc;
unsigned long last_end_request;
unsigned long last_queue;
sector_t last_request_pos;
unsigned long last_queue;
unsigned long ttime_total;
unsigned long ttime_samples;
unsigned long ttime_mean;
unsigned int seek_samples;
u64 seek_total;
sector_t seek_mean;
struct list_head queue_list;
void (*dtor)(struct cfq_io_context *);
void (*exit)(struct cfq_io_context *);
void (*dtor)(struct io_context *); /* destructor */
void (*exit)(struct io_context *); /* called on task exit */
};
/*
@ -94,7 +98,7 @@ struct io_context {
int nr_batch_requests; /* Number of requests left in the batch */
struct as_io_context *aic;
struct cfq_io_context *cic;
struct rb_root cic_root;
};
void put_io_context(struct io_context *ioc);