[PATCH] cfq-iosched: cleanups, fixes, dead code removal
A collection of little fixes and cleanups: - We don't use the 'queued' sysfs exported attribute, since the may_queue() logic was rewritten. So kill it. - Remove dead defines. - cfq_set_active_queue() can be rewritten cleaner with else if conditions. - Several places had cfq_exit_cfqq() like logic, abstract that out and use that. - Annotate the cfqq kmem_cache_alloc() so the allocator knows that this is a repeat allocation if it fails with __GFP_WAIT set. Allows the allocator to start freeing some memory, if needed. CFQ already loops for this condition, so might as well pass the hint down. - Remove cfqd->rq_starved logic. It's not needed anymore after we dropped the crq allocation in cfq_set_request(). - Remove uneeded parameter passing. Signed-off-by: Jens Axboe <axboe@suse.de>
This commit is contained in:
Jens Axboe
Jens Axboe
parent
e6a1c874a0
commit
89850f7ee9
1 changed files with 72 additions and 116 deletions
|
|
@ -17,7 +17,6 @@
|
|||
* tunables
|
||||
*/
|
||||
static const int cfq_quantum = 4; /* max queue in one round of service */
|
||||
static const int cfq_queued = 8; /* minimum rq allocate limit per-queue*/
|
||||
static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 };
|
||||
static const int cfq_back_max = 16 * 1024; /* maximum backwards seek, in KiB */
|
||||
static const int cfq_back_penalty = 2; /* penalty of a backwards seek */
|
||||
|
|
@ -54,7 +53,6 @@ static struct completion *ioc_gone;
|
|||
|
||||
#define CFQ_PRIO_LISTS IOPRIO_BE_NR
|
||||
#define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
|
||||
#define cfq_class_be(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_BE)
|
||||
#define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT)
|
||||
|
||||
#define ASYNC (0)
|
||||
|
|
@ -98,9 +96,6 @@ struct cfq_data {
|
|||
int rq_in_driver;
|
||||
int hw_tag;
|
||||
|
||||
/*
|
||||
* schedule slice state info
|
||||
*/
|
||||
/*
|
||||
* idle window management
|
||||
*/
|
||||
|
|
@ -117,13 +112,10 @@ struct cfq_data {
|
|||
sector_t last_sector;
|
||||
unsigned long last_end_request;
|
||||
|
||||
unsigned int rq_starved;
|
||||
|
||||
/*
|
||||
* tunables, see top of file
|
||||
*/
|
||||
unsigned int cfq_quantum;
|
||||
unsigned int cfq_queued;
|
||||
unsigned int cfq_fifo_expire[2];
|
||||
unsigned int cfq_back_penalty;
|
||||
unsigned int cfq_back_max;
|
||||
|
|
@ -484,12 +476,14 @@ cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
|
|||
{
|
||||
struct task_struct *tsk = current;
|
||||
pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio));
|
||||
sector_t sector = bio->bi_sector + bio_sectors(bio);
|
||||
struct cfq_queue *cfqq;
|
||||
|
||||
cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio);
|
||||
if (cfqq)
|
||||
if (cfqq) {
|
||||
sector_t sector = bio->bi_sector + bio_sectors(bio);
|
||||
|
||||
return elv_rb_find(&cfqq->sort_list, sector);
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
|
@ -699,26 +693,25 @@ static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd)
|
|||
{
|
||||
struct cfq_queue *cfqq = NULL;
|
||||
|
||||
/*
|
||||
* if current list is non-empty, grab first entry. if it is empty,
|
||||
* get next prio level and grab first entry then if any are spliced
|
||||
*/
|
||||
if (!list_empty(&cfqd->cur_rr) || cfq_get_next_prio_level(cfqd) != -1)
|
||||
if (!list_empty(&cfqd->cur_rr) || cfq_get_next_prio_level(cfqd) != -1) {
|
||||
/*
|
||||
* if current list is non-empty, grab first entry. if it is
|
||||
* empty, get next prio level and grab first entry then if any
|
||||
* are spliced
|
||||
*/
|
||||
cfqq = list_entry_cfqq(cfqd->cur_rr.next);
|
||||
|
||||
/*
|
||||
* If no new queues are available, check if the busy list has some
|
||||
* before falling back to idle io.
|
||||
*/
|
||||
if (!cfqq && !list_empty(&cfqd->busy_rr))
|
||||
} else if (!list_empty(&cfqd->busy_rr)) {
|
||||
/*
|
||||
* If no new queues are available, check if the busy list has
|
||||
* some before falling back to idle io.
|
||||
*/
|
||||
cfqq = list_entry_cfqq(cfqd->busy_rr.next);
|
||||
|
||||
/*
|
||||
* if we have idle queues and no rt or be queues had pending
|
||||
* requests, either allow immediate service if the grace period
|
||||
* has passed or arm the idle grace timer
|
||||
*/
|
||||
if (!cfqq && !list_empty(&cfqd->idle_rr)) {
|
||||
} else if (!list_empty(&cfqd->idle_rr)) {
|
||||
/*
|
||||
* if we have idle queues and no rt or be queues had pending
|
||||
* requests, either allow immediate service if the grace period
|
||||
* has passed or arm the idle grace timer
|
||||
*/
|
||||
unsigned long end = cfqd->last_end_request + CFQ_IDLE_GRACE;
|
||||
|
||||
if (time_after_eq(jiffies, end))
|
||||
|
|
@ -793,18 +786,19 @@ static inline struct request *cfq_check_fifo(struct cfq_queue *cfqq)
|
|||
{
|
||||
struct cfq_data *cfqd = cfqq->cfqd;
|
||||
struct request *rq;
|
||||
int fifo;
|
||||
|
||||
if (cfq_cfqq_fifo_expire(cfqq))
|
||||
return NULL;
|
||||
if (list_empty(&cfqq->fifo))
|
||||
return NULL;
|
||||
|
||||
if (!list_empty(&cfqq->fifo)) {
|
||||
int fifo = cfq_cfqq_class_sync(cfqq);
|
||||
fifo = cfq_cfqq_class_sync(cfqq);
|
||||
rq = rq_entry_fifo(cfqq->fifo.next);
|
||||
|
||||
rq = rq_entry_fifo(cfqq->fifo.next);
|
||||
if (time_after(jiffies, rq->start_time + cfqd->cfq_fifo_expire[fifo])) {
|
||||
cfq_mark_cfqq_fifo_expire(cfqq);
|
||||
return rq;
|
||||
}
|
||||
if (time_after(jiffies, rq->start_time + cfqd->cfq_fifo_expire[fifo])) {
|
||||
cfq_mark_cfqq_fifo_expire(cfqq);
|
||||
return rq;
|
||||
}
|
||||
|
||||
return NULL;
|
||||
|
|
@ -1096,40 +1090,48 @@ static void cfq_trim(struct io_context *ioc)
|
|||
cfq_free_io_context(ioc);
|
||||
}
|
||||
|
||||
static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
|
||||
{
|
||||
if (unlikely(cfqq == cfqd->active_queue))
|
||||
__cfq_slice_expired(cfqd, cfqq, 0);
|
||||
|
||||
cfq_put_queue(cfqq);
|
||||
}
|
||||
|
||||
static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
|
||||
struct cfq_io_context *cic)
|
||||
{
|
||||
if (cic->cfqq[ASYNC]) {
|
||||
cfq_exit_cfqq(cfqd, cic->cfqq[ASYNC]);
|
||||
cic->cfqq[ASYNC] = NULL;
|
||||
}
|
||||
|
||||
if (cic->cfqq[SYNC]) {
|
||||
cfq_exit_cfqq(cfqd, cic->cfqq[SYNC]);
|
||||
cic->cfqq[SYNC] = NULL;
|
||||
}
|
||||
|
||||
cic->key = NULL;
|
||||
list_del_init(&cic->queue_list);
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* Called with interrupts disabled
|
||||
*/
|
||||
static void cfq_exit_single_io_context(struct cfq_io_context *cic)
|
||||
{
|
||||
struct cfq_data *cfqd = cic->key;
|
||||
request_queue_t *q;
|
||||
|
||||
if (!cfqd)
|
||||
return;
|
||||
|
||||
q = cfqd->queue;
|
||||
|
||||
WARN_ON(!irqs_disabled());
|
||||
|
||||
spin_lock(q->queue_lock);
|
||||
if (cfqd) {
|
||||
request_queue_t *q = cfqd->queue;
|
||||
|
||||
if (cic->cfqq[ASYNC]) {
|
||||
if (unlikely(cic->cfqq[ASYNC] == cfqd->active_queue))
|
||||
__cfq_slice_expired(cfqd, cic->cfqq[ASYNC], 0);
|
||||
cfq_put_queue(cic->cfqq[ASYNC]);
|
||||
cic->cfqq[ASYNC] = NULL;
|
||||
spin_lock(q->queue_lock);
|
||||
__cfq_exit_single_io_context(cfqd, cic);
|
||||
spin_unlock(q->queue_lock);
|
||||
}
|
||||
|
||||
if (cic->cfqq[SYNC]) {
|
||||
if (unlikely(cic->cfqq[SYNC] == cfqd->active_queue))
|
||||
__cfq_slice_expired(cfqd, cic->cfqq[SYNC], 0);
|
||||
cfq_put_queue(cic->cfqq[SYNC]);
|
||||
cic->cfqq[SYNC] = NULL;
|
||||
}
|
||||
|
||||
cic->key = NULL;
|
||||
list_del_init(&cic->queue_list);
|
||||
spin_unlock(q->queue_lock);
|
||||
}
|
||||
|
||||
static void cfq_exit_io_context(struct io_context *ioc)
|
||||
|
|
@ -1286,8 +1288,14 @@ cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk,
|
|||
cfqq = new_cfqq;
|
||||
new_cfqq = NULL;
|
||||
} else if (gfp_mask & __GFP_WAIT) {
|
||||
/*
|
||||
* Inform the allocator of the fact that we will
|
||||
* just repeat this allocation if it fails, to allow
|
||||
* the allocator to do whatever it needs to attempt to
|
||||
* free memory.
|
||||
*/
|
||||
spin_unlock_irq(cfqd->queue->queue_lock);
|
||||
new_cfqq = kmem_cache_alloc(cfq_pool, gfp_mask);
|
||||
new_cfqq = kmem_cache_alloc(cfq_pool, gfp_mask|__GFP_NOFAIL);
|
||||
spin_lock_irq(cfqd->queue->queue_lock);
|
||||
goto retry;
|
||||
} else {
|
||||
|
|
@ -1739,9 +1747,7 @@ static void cfq_prio_boost(struct cfq_queue *cfqq)
|
|||
cfq_resort_rr_list(cfqq, 0);
|
||||
}
|
||||
|
||||
static inline int
|
||||
__cfq_may_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq,
|
||||
struct task_struct *task, int rw)
|
||||
static inline int __cfq_may_queue(struct cfq_queue *cfqq)
|
||||
{
|
||||
if ((cfq_cfqq_wait_request(cfqq) || cfq_cfqq_must_alloc(cfqq)) &&
|
||||
!cfq_cfqq_must_alloc_slice(cfqq)) {
|
||||
|
|
@ -1769,27 +1775,12 @@ static int cfq_may_queue(request_queue_t *q, int rw)
|
|||
cfq_init_prio_data(cfqq);
|
||||
cfq_prio_boost(cfqq);
|
||||
|
||||
return __cfq_may_queue(cfqd, cfqq, tsk, rw);
|
||||
return __cfq_may_queue(cfqq);
|
||||
}
|
||||
|
||||
return ELV_MQUEUE_MAY;
|
||||
}
|
||||
|
||||
static void cfq_check_waiters(request_queue_t *q, struct cfq_queue *cfqq)
|
||||
{
|
||||
struct cfq_data *cfqd = q->elevator->elevator_data;
|
||||
|
||||
if (unlikely(cfqd->rq_starved)) {
|
||||
struct request_list *rl = &q->rq;
|
||||
|
||||
smp_mb();
|
||||
if (waitqueue_active(&rl->wait[READ]))
|
||||
wake_up(&rl->wait[READ]);
|
||||
if (waitqueue_active(&rl->wait[WRITE]))
|
||||
wake_up(&rl->wait[WRITE]);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* queue lock held here
|
||||
*/
|
||||
|
|
@ -1808,7 +1799,6 @@ static void cfq_put_request(request_queue_t *q, struct request *rq)
|
|||
rq->elevator_private = NULL;
|
||||
rq->elevator_private2 = NULL;
|
||||
|
||||
cfq_check_waiters(q, cfqq);
|
||||
cfq_put_queue(cfqq);
|
||||
}
|
||||
}
|
||||
|
|
@ -1848,7 +1838,6 @@ cfq_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask)
|
|||
|
||||
cfqq->allocated[rw]++;
|
||||
cfq_clear_cfqq_must_alloc(cfqq);
|
||||
cfqd->rq_starved = 0;
|
||||
atomic_inc(&cfqq->ref);
|
||||
|
||||
spin_unlock_irqrestore(q->queue_lock, flags);
|
||||
|
|
@ -1860,12 +1849,7 @@ cfq_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask)
|
|||
queue_fail:
|
||||
if (cic)
|
||||
put_io_context(cic->ioc);
|
||||
/*
|
||||
* mark us rq allocation starved. we need to kickstart the process
|
||||
* ourselves if there are no pending requests that can do it for us.
|
||||
* that would be an extremely rare OOM situation
|
||||
*/
|
||||
cfqd->rq_starved = 1;
|
||||
|
||||
cfq_schedule_dispatch(cfqd);
|
||||
spin_unlock_irqrestore(q->queue_lock, flags);
|
||||
return 1;
|
||||
|
|
@ -1874,25 +1858,9 @@ cfq_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask)
|
|||
static void cfq_kick_queue(void *data)
|
||||
{
|
||||
request_queue_t *q = data;
|
||||
struct cfq_data *cfqd = q->elevator->elevator_data;
|
||||
unsigned long flags;
|
||||
|
||||
spin_lock_irqsave(q->queue_lock, flags);
|
||||
|
||||
if (cfqd->rq_starved) {
|
||||
struct request_list *rl = &q->rq;
|
||||
|
||||
/*
|
||||
* we aren't guaranteed to get a request after this, but we
|
||||
* have to be opportunistic
|
||||
*/
|
||||
smp_mb();
|
||||
if (waitqueue_active(&rl->wait[READ]))
|
||||
wake_up(&rl->wait[READ]);
|
||||
if (waitqueue_active(&rl->wait[WRITE]))
|
||||
wake_up(&rl->wait[WRITE]);
|
||||
}
|
||||
|
||||
blk_remove_plug(q);
|
||||
q->request_fn(q);
|
||||
spin_unlock_irqrestore(q->queue_lock, flags);
|
||||
|
|
@ -1987,16 +1955,8 @@ static void cfq_exit_queue(elevator_t *e)
|
|||
struct cfq_io_context *cic = list_entry(cfqd->cic_list.next,
|
||||
struct cfq_io_context,
|
||||
queue_list);
|
||||
if (cic->cfqq[ASYNC]) {
|
||||
cfq_put_queue(cic->cfqq[ASYNC]);
|
||||
cic->cfqq[ASYNC] = NULL;
|
||||
}
|
||||
if (cic->cfqq[SYNC]) {
|
||||
cfq_put_queue(cic->cfqq[SYNC]);
|
||||
cic->cfqq[SYNC] = NULL;
|
||||
}
|
||||
cic->key = NULL;
|
||||
list_del_init(&cic->queue_list);
|
||||
|
||||
__cfq_exit_single_io_context(cfqd, cic);
|
||||
}
|
||||
|
||||
spin_unlock_irq(q->queue_lock);
|
||||
|
|
@ -2047,7 +2007,6 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e)
|
|||
|
||||
INIT_WORK(&cfqd->unplug_work, cfq_kick_queue, q);
|
||||
|
||||
cfqd->cfq_queued = cfq_queued;
|
||||
cfqd->cfq_quantum = cfq_quantum;
|
||||
cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0];
|
||||
cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1];
|
||||
|
|
@ -2119,7 +2078,6 @@ static ssize_t __FUNC(elevator_t *e, char *page) \
|
|||
return cfq_var_show(__data, (page)); \
|
||||
}
|
||||
SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0);
|
||||
SHOW_FUNCTION(cfq_queued_show, cfqd->cfq_queued, 0);
|
||||
SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1);
|
||||
SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1);
|
||||
SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0);
|
||||
|
|
@ -2147,7 +2105,6 @@ static ssize_t __FUNC(elevator_t *e, const char *page, size_t count) \
|
|||
return ret; \
|
||||
}
|
||||
STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0);
|
||||
STORE_FUNCTION(cfq_queued_store, &cfqd->cfq_queued, 1, UINT_MAX, 0);
|
||||
STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, UINT_MAX, 1);
|
||||
STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, UINT_MAX, 1);
|
||||
STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0);
|
||||
|
|
@ -2163,7 +2120,6 @@ STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, UINT_MAX,
|
|||
|
||||
static struct elv_fs_entry cfq_attrs[] = {
|
||||
CFQ_ATTR(quantum),
|
||||
CFQ_ATTR(queued),
|
||||
CFQ_ATTR(fifo_expire_sync),
|
||||
CFQ_ATTR(fifo_expire_async),
|
||||
CFQ_ATTR(back_seek_max),
|
||||
|
|
|
|||
Loading…
Reference in a new issue