Commit d4928196 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'cfq-ioc-share' of git://git.kernel.dk/linux-2.6-block

* 'cfq-ioc-share' of git://git.kernel.dk/linux-2.6-block:
  cfq-iosched: kill some big inlines
  cfq-iosched: relax IOPRIO_CLASS_IDLE restrictions
  kernel: add CLONE_IO to specifically request sharing of IO contexts
  io_context sharing - anticipatory changes
  block: cfq: make the io contect sharing lockless
  io_context sharing - cfq changes
  io context sharing: preliminary support
  ioprio: move io priority from task_struct to io_context
parents bb04af0e febffd61
...@@ -170,9 +170,11 @@ static void free_as_io_context(struct as_io_context *aic) ...@@ -170,9 +170,11 @@ static void free_as_io_context(struct as_io_context *aic)
static void as_trim(struct io_context *ioc) static void as_trim(struct io_context *ioc)
{ {
spin_lock(&ioc->lock);
if (ioc->aic) if (ioc->aic)
free_as_io_context(ioc->aic); free_as_io_context(ioc->aic);
ioc->aic = NULL; ioc->aic = NULL;
spin_unlock(&ioc->lock);
} }
/* Called when the task exits */ /* Called when the task exits */
...@@ -462,7 +464,9 @@ static void as_antic_timeout(unsigned long data) ...@@ -462,7 +464,9 @@ static void as_antic_timeout(unsigned long data)
spin_lock_irqsave(q->queue_lock, flags); spin_lock_irqsave(q->queue_lock, flags);
if (ad->antic_status == ANTIC_WAIT_REQ if (ad->antic_status == ANTIC_WAIT_REQ
|| ad->antic_status == ANTIC_WAIT_NEXT) { || ad->antic_status == ANTIC_WAIT_NEXT) {
struct as_io_context *aic = ad->io_context->aic; struct as_io_context *aic;
spin_lock(&ad->io_context->lock);
aic = ad->io_context->aic;
ad->antic_status = ANTIC_FINISHED; ad->antic_status = ANTIC_FINISHED;
kblockd_schedule_work(&ad->antic_work); kblockd_schedule_work(&ad->antic_work);
...@@ -475,6 +479,7 @@ static void as_antic_timeout(unsigned long data) ...@@ -475,6 +479,7 @@ static void as_antic_timeout(unsigned long data)
/* process not "saved" by a cooperating request */ /* process not "saved" by a cooperating request */
ad->exit_no_coop = (7*ad->exit_no_coop + 256)/8; ad->exit_no_coop = (7*ad->exit_no_coop + 256)/8;
} }
spin_unlock(&ad->io_context->lock);
} }
spin_unlock_irqrestore(q->queue_lock, flags); spin_unlock_irqrestore(q->queue_lock, flags);
} }
...@@ -635,9 +640,11 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq) ...@@ -635,9 +640,11 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
ioc = ad->io_context; ioc = ad->io_context;
BUG_ON(!ioc); BUG_ON(!ioc);
spin_lock(&ioc->lock);
if (rq && ioc == RQ_IOC(rq)) { if (rq && ioc == RQ_IOC(rq)) {
/* request from same process */ /* request from same process */
spin_unlock(&ioc->lock);
return 1; return 1;
} }
...@@ -646,20 +653,25 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq) ...@@ -646,20 +653,25 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
* In this situation status should really be FINISHED, * In this situation status should really be FINISHED,
* however the timer hasn't had the chance to run yet. * however the timer hasn't had the chance to run yet.
*/ */
spin_unlock(&ioc->lock);
return 1; return 1;
} }
aic = ioc->aic; aic = ioc->aic;
if (!aic) if (!aic) {
spin_unlock(&ioc->lock);
return 0; return 0;
}
if (atomic_read(&aic->nr_queued) > 0) { if (atomic_read(&aic->nr_queued) > 0) {
/* process has more requests queued */ /* process has more requests queued */
spin_unlock(&ioc->lock);
return 1; return 1;
} }
if (atomic_read(&aic->nr_dispatched) > 0) { if (atomic_read(&aic->nr_dispatched) > 0) {
/* process has more requests dispatched */ /* process has more requests dispatched */
spin_unlock(&ioc->lock);
return 1; return 1;
} }
...@@ -680,6 +692,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq) ...@@ -680,6 +692,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
} }
as_update_iohist(ad, aic, rq); as_update_iohist(ad, aic, rq);
spin_unlock(&ioc->lock);
return 1; return 1;
} }
...@@ -688,20 +701,27 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq) ...@@ -688,20 +701,27 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
if (aic->ttime_samples == 0) if (aic->ttime_samples == 0)
ad->exit_prob = (7*ad->exit_prob + 256)/8; ad->exit_prob = (7*ad->exit_prob + 256)/8;
if (ad->exit_no_coop > 128) if (ad->exit_no_coop > 128) {
spin_unlock(&ioc->lock);
return 1; return 1;
} }
}
if (aic->ttime_samples == 0) { if (aic->ttime_samples == 0) {
if (ad->new_ttime_mean > ad->antic_expire) if (ad->new_ttime_mean > ad->antic_expire) {
spin_unlock(&ioc->lock);
return 1; return 1;
if (ad->exit_prob * ad->exit_no_coop > 128*256) }
if (ad->exit_prob * ad->exit_no_coop > 128*256) {
spin_unlock(&ioc->lock);
return 1; return 1;
}
} else if (aic->ttime_mean > ad->antic_expire) { } else if (aic->ttime_mean > ad->antic_expire) {
/* the process thinks too much between requests */ /* the process thinks too much between requests */
spin_unlock(&ioc->lock);
return 1; return 1;
} }
spin_unlock(&ioc->lock);
return 0; return 0;
} }
...@@ -1255,7 +1275,9 @@ static void as_merged_requests(struct request_queue *q, struct request *req, ...@@ -1255,7 +1275,9 @@ static void as_merged_requests(struct request_queue *q, struct request *req,
* Don't copy here but swap, because when anext is * Don't copy here but swap, because when anext is
* removed below, it must contain the unused context * removed below, it must contain the unused context
*/ */
double_spin_lock(&rioc->lock, &nioc->lock, rioc < nioc);
swap_io_context(&rioc, &nioc); swap_io_context(&rioc, &nioc);
double_spin_unlock(&rioc->lock, &nioc->lock, rioc < nioc);
} }
} }
......
...@@ -26,9 +26,9 @@ static const int cfq_slice_async_rq = 2; ...@@ -26,9 +26,9 @@ static const int cfq_slice_async_rq = 2;
static int cfq_slice_idle = HZ / 125; static int cfq_slice_idle = HZ / 125;
/* /*
* grace period before allowing idle class to get disk access * offset from end of service tree
*/ */
#define CFQ_IDLE_GRACE (HZ / 10) #define CFQ_IDLE_DELAY (HZ / 5)
/* /*
* below this threshold, we consider thinktime immediate * below this threshold, we consider thinktime immediate
...@@ -98,8 +98,6 @@ struct cfq_data { ...@@ -98,8 +98,6 @@ struct cfq_data {
struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR];
struct cfq_queue *async_idle_cfqq; struct cfq_queue *async_idle_cfqq;
struct timer_list idle_class_timer;
sector_t last_position; sector_t last_position;
unsigned long last_end_request; unsigned long last_end_request;
...@@ -199,8 +197,8 @@ CFQ_CFQQ_FNS(sync); ...@@ -199,8 +197,8 @@ CFQ_CFQQ_FNS(sync);
static void cfq_dispatch_insert(struct request_queue *, struct request *); static void cfq_dispatch_insert(struct request_queue *, struct request *);
static struct cfq_queue *cfq_get_queue(struct cfq_data *, int, static struct cfq_queue *cfq_get_queue(struct cfq_data *, int,
struct task_struct *, gfp_t); struct io_context *, gfp_t);
static struct cfq_io_context *cfq_cic_rb_lookup(struct cfq_data *, static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *,
struct io_context *); struct io_context *);
static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic, static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic,
...@@ -384,12 +382,15 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2) ...@@ -384,12 +382,15 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2)
/* /*
* The below is leftmost cache rbtree addon * The below is leftmost cache rbtree addon
*/ */
static struct rb_node *cfq_rb_first(struct cfq_rb_root *root) static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root)
{ {
if (!root->left) if (!root->left)
root->left = rb_first(&root->rb); root->left = rb_first(&root->rb);
return root->left; if (root->left)
return rb_entry(root->left, struct cfq_queue, rb_node);
return NULL;
} }
static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root)
...@@ -446,12 +447,20 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd, ...@@ -446,12 +447,20 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
static void cfq_service_tree_add(struct cfq_data *cfqd, static void cfq_service_tree_add(struct cfq_data *cfqd,
struct cfq_queue *cfqq, int add_front) struct cfq_queue *cfqq, int add_front)
{ {
struct rb_node **p = &cfqd->service_tree.rb.rb_node; struct rb_node **p, *parent;
struct rb_node *parent = NULL; struct cfq_queue *__cfqq;
unsigned long rb_key; unsigned long rb_key;
int left; int left;
if (!add_front) { if (cfq_class_idle(cfqq)) {
rb_key = CFQ_IDLE_DELAY;
parent = rb_last(&cfqd->service_tree.rb);
if (parent && parent != &cfqq->rb_node) {
__cfqq = rb_entry(parent, struct cfq_queue, rb_node);
rb_key += __cfqq->rb_key;
} else
rb_key += jiffies;
} else if (!add_front) {
rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies;
rb_key += cfqq->slice_resid; rb_key += cfqq->slice_resid;
cfqq->slice_resid = 0; cfqq->slice_resid = 0;
...@@ -469,8 +478,9 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, ...@@ -469,8 +478,9 @@ static void cfq_service_tree_add(struct cfq_data *cfqd,
} }
left = 1; left = 1;
parent = NULL;
p = &cfqd->service_tree.rb.rb_node;
while (*p) { while (*p) {
struct cfq_queue *__cfqq;
struct rb_node **n; struct rb_node **n;
parent = *p; parent = *p;
...@@ -524,8 +534,7 @@ static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq) ...@@ -524,8 +534,7 @@ static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq)
* add to busy list of queues for service, trying to be fair in ordering * add to busy list of queues for service, trying to be fair in ordering
* the pending list according to last request service * the pending list according to last request service
*/ */
static inline void static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{ {
BUG_ON(cfq_cfqq_on_rr(cfqq)); BUG_ON(cfq_cfqq_on_rr(cfqq));
cfq_mark_cfqq_on_rr(cfqq); cfq_mark_cfqq_on_rr(cfqq);
...@@ -538,8 +547,7 @@ cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) ...@@ -538,8 +547,7 @@ cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
* Called when the cfqq no longer has requests pending, remove it from * Called when the cfqq no longer has requests pending, remove it from
* the service tree. * the service tree.
*/ */
static inline void static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{ {
BUG_ON(!cfq_cfqq_on_rr(cfqq)); BUG_ON(!cfq_cfqq_on_rr(cfqq));
cfq_clear_cfqq_on_rr(cfqq); cfq_clear_cfqq_on_rr(cfqq);
...@@ -554,7 +562,7 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) ...@@ -554,7 +562,7 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
/* /*
* rb tree support functions * rb tree support functions
*/ */
static inline void cfq_del_rq_rb(struct request *rq) static void cfq_del_rq_rb(struct request *rq)
{ {
struct cfq_queue *cfqq = RQ_CFQQ(rq); struct cfq_queue *cfqq = RQ_CFQQ(rq);
struct cfq_data *cfqd = cfqq->cfqd; struct cfq_data *cfqd = cfqq->cfqd;
...@@ -594,8 +602,7 @@ static void cfq_add_rq_rb(struct request *rq) ...@@ -594,8 +602,7 @@ static void cfq_add_rq_rb(struct request *rq)
BUG_ON(!cfqq->next_rq); BUG_ON(!cfqq->next_rq);
} }
static inline void static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
{ {
elv_rb_del(&cfqq->sort_list, rq); elv_rb_del(&cfqq->sort_list, rq);
cfqq->queued[rq_is_sync(rq)]--; cfqq->queued[rq_is_sync(rq)]--;
...@@ -609,7 +616,7 @@ cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) ...@@ -609,7 +616,7 @@ cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
struct cfq_io_context *cic; struct cfq_io_context *cic;
struct cfq_queue *cfqq; struct cfq_queue *cfqq;
cic = cfq_cic_rb_lookup(cfqd, tsk->io_context); cic = cfq_cic_lookup(cfqd, tsk->io_context);
if (!cic) if (!cic)
return NULL; return NULL;
...@@ -721,7 +728,7 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq, ...@@ -721,7 +728,7 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq,
* Lookup the cfqq that this bio will be queued with. Allow * Lookup the cfqq that this bio will be queued with. Allow
* merge only if rq is queued there. * merge only if rq is queued there.
*/ */
cic = cfq_cic_rb_lookup(cfqd, current->io_context); cic = cfq_cic_lookup(cfqd, current->io_context);
if (!cic) if (!cic)
return 0; return 0;
...@@ -732,15 +739,10 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq, ...@@ -732,15 +739,10 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq,
return 0; return 0;
} }
static inline void static void __cfq_set_active_queue(struct cfq_data *cfqd,
__cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) struct cfq_queue *cfqq)
{ {
if (cfqq) { if (cfqq) {
/*
* stop potential idle class queues waiting service
*/
del_timer(&cfqd->idle_class_timer);
cfqq->slice_end = 0; cfqq->slice_end = 0;
cfq_clear_cfqq_must_alloc_slice(cfqq); cfq_clear_cfqq_must_alloc_slice(cfqq);
cfq_clear_cfqq_fifo_expire(cfqq); cfq_clear_cfqq_fifo_expire(cfqq);
...@@ -789,47 +791,16 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, int timed_out) ...@@ -789,47 +791,16 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, int timed_out)
__cfq_slice_expired(cfqd, cfqq, timed_out); __cfq_slice_expired(cfqd, cfqq, timed_out);
} }
static int start_idle_class_timer(struct cfq_data *cfqd)
{
unsigned long end = cfqd->last_end_request + CFQ_IDLE_GRACE;
unsigned long now = jiffies;
if (time_before(now, end) &&
time_after_eq(now, cfqd->last_end_request)) {
mod_timer(&cfqd->idle_class_timer, end);
return 1;
}
return 0;
}
/* /*
* Get next queue for service. Unless we have a queue preemption, * Get next queue for service. Unless we have a queue preemption,
* we'll simply select the first cfqq in the service tree. * we'll simply select the first cfqq in the service tree.
*/ */
static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd)
{ {
struct cfq_queue *cfqq;
struct rb_node *n;
if (RB_EMPTY_ROOT(&cfqd->service_tree.rb)) if (RB_EMPTY_ROOT(&cfqd->service_tree.rb))
return NULL; return NULL;
n = cfq_rb_first(&cfqd->service_tree); return cfq_rb_first(&cfqd->service_tree);
cfqq = rb_entry(n, struct cfq_queue, rb_node);
if (cfq_class_idle(cfqq)) {
/*
* 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 (start_idle_class_timer(cfqd))
cfqq = NULL;
}
return cfqq;
} }
/* /*
...@@ -895,7 +866,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd) ...@@ -895,7 +866,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
* task has exited, don't wait * task has exited, don't wait
*/ */
cic = cfqd->active_cic; cic = cfqd->active_cic;
if (!cic || !cic->ioc->task) if (!cic || !atomic_read(&cic->ioc->nr_tasks))
return; return;
/* /*
...@@ -939,7 +910,7 @@ static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) ...@@ -939,7 +910,7 @@ static void cfq_dispatch_insert(struct request_queue *q, struct request *rq)
/* /*
* return expired entry, or NULL to just start from scratch in rbtree * return expired entry, or NULL to just start from scratch in rbtree
*/ */
static inline struct request *cfq_check_fifo(struct cfq_queue *cfqq) static struct request *cfq_check_fifo(struct cfq_queue *cfqq)
{ {
struct cfq_data *cfqd = cfqq->cfqd; struct cfq_data *cfqd = cfqq->cfqd;
struct request *rq; struct request *rq;
...@@ -1068,7 +1039,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq, ...@@ -1068,7 +1039,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
return dispatched; return dispatched;
} }
static inline int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq)
{ {
int dispatched = 0; int dispatched = 0;
...@@ -1087,14 +1058,11 @@ static inline int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) ...@@ -1087,14 +1058,11 @@ static inline int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq)
*/ */
static int cfq_forced_dispatch(struct cfq_data *cfqd) static int cfq_forced_dispatch(struct cfq_data *cfqd)
{ {
struct cfq_queue *cfqq;
int dispatched = 0; int dispatched = 0;
struct rb_node *n;
while ((n = cfq_rb_first(&cfqd->service_tree)) != NULL) {
struct cfq_queue *cfqq = rb_entry(n, struct cfq_queue, rb_node);
while ((cfqq = cfq_rb_first(&cfqd->service_tree)) != NULL)
dispatched += __cfq_forced_dispatch_cfqq(cfqq); dispatched += __cfq_forced_dispatch_cfqq(cfqq);
}
cfq_slice_expired(cfqd, 0); cfq_slice_expired(cfqd, 0);
...@@ -1170,20 +1138,69 @@ static void cfq_put_queue(struct cfq_queue *cfqq) ...@@ -1170,20 +1138,69 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
kmem_cache_free(cfq_pool, cfqq); kmem_cache_free(cfq_pool, cfqq);
} }
static void cfq_free_io_context(struct io_context *ioc) /*
* Call func for each cic attached to this ioc. Returns number of cic's seen.
*/
#define CIC_GANG_NR 16
static unsigned int
call_for_each_cic(struct io_context *ioc,
void (*func)(struct io_context *, struct cfq_io_context *))
{ {
struct cfq_io_context *__cic; struct cfq_io_context *cics[CIC_GANG_NR];
struct rb_node *n; unsigned long index = 0;
int freed = 0; unsigned int called = 0;
int nr;
ioc->ioc_data = NULL; rcu_read_lock();
while ((n = rb_first(&ioc->cic_root)) != NULL) { do {
__cic = rb_entry(n, struct cfq_io_context, rb_node); int i;
rb_erase(&__cic->rb_node, &ioc->cic_root);
kmem_cache_free(cfq_ioc_pool, __cic); /*
freed++; * Perhaps there's a better way - this just gang lookups from
} * 0 to the end, restarting after each CIC_GANG_NR from the
* last key + 1.
*/
nr = radix_tree_gang_lookup(&ioc->radix_root, (void **) cics,
index, CIC_GANG_NR);
if (!nr)
break;
called += nr;
index = 1 + (unsigned long) cics[nr - 1]->key;
for (i = 0; i < nr; i++)
func(ioc, cics[i]);
} while (nr == CIC_GANG_NR);
rcu_read_unlock();
return called;
}
static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic)
{
unsigned long flags;
BUG_ON(!cic->dead_key);
spin_lock_irqsave(&ioc->lock, flags);
radix_tree_delete(&ioc->radix_root, cic->dead_key);
spin_unlock_irqrestore(&ioc->lock, flags);
kmem_cache_free(cfq_ioc_pool, cic);
}
static void cfq_free_io_context(struct io_context *ioc)
{
int freed;
/*
* ioc->refcount is zero here, so no more cic's are allowed to be
* linked into this ioc. So it should be ok to iterate over the known
* list, we will see all cic's since no new ones are added.
*/
freed = call_for_each_cic(ioc, cic_free_func);
elv_ioc_count_mod(ioc_count, -freed); elv_ioc_count_mod(ioc_count, -freed);
...@@ -1205,7 +1222,12 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd, ...@@ -1205,7 +1222,12 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
struct cfq_io_context *cic) struct cfq_io_context *cic)
{ {
list_del_init(&cic->queue_list); list_del_init(&cic->queue_list);
/*
* Make sure key == NULL is seen for dead queues
*/
smp_wmb(); smp_wmb();
cic->dead_key = (unsigned long) cic->key;
cic->key = NULL; cic->key = NULL;
if (cic->cfqq[ASYNC]) { if (cic->cfqq[ASYNC]) {
...@@ -1219,16 +1241,18 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd, ...@@ -1219,16 +1241,18 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
} }
} }
static void cfq_exit_single_io_context(struct cfq_io_context *cic) static void cfq_exit_single_io_context(struct io_context *ioc,
struct cfq_io_context *cic)
{ {
struct cfq_data *cfqd = cic->key; struct cfq_data *cfqd = cic->key;
if (cfqd) { if (cfqd) {
struct request_queue *q = cfqd->queue; struct request_queue *q = cfqd->queue;
unsigned long flags;
spin_lock_irq(q->queue_lock); spin_lock_irqsave(q->queue_lock, flags);
__cfq_exit_single_io_context(cfqd, cic); __cfq_exit_single_io_context(cfqd, cic);
spin_unlock_irq(q->queue_lock); spin_unlock_irqrestore(q->queue_lock, flags);
} }
} }
...@@ -1238,21 +1262,8 @@ static void cfq_exit_single_io_context(struct cfq_io_context *cic) ...@@ -1238,21 +1262,8 @@ static void cfq_exit_single_io_context(struct cfq_io_context *cic)
*/ */
static void cfq_exit_io_context(struct io_context *ioc) static void cfq_exit_io_context(struct io_context *ioc)
{ {
struct cfq_io_context *__cic; rcu_assign_pointer(ioc->ioc_data, NULL);
struct rb_node *n; call_for_each_cic(ioc, cfq_exit_single_io_context);
ioc->ioc_data = NULL;
/*
* put the reference this task is holding to the various queues
*/
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);
}
} }
static struct cfq_io_context * static struct cfq_io_context *
...@@ -1273,7 +1284,7 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) ...@@ -1273,7 +1284,7 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
return cic; return cic;
} }
static void cfq_init_prio_data(struct cfq_queue *cfqq) static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc)
{ {
struct task_struct *tsk = current; struct task_struct *tsk = current;
int ioprio_class; int ioprio_class;
...@@ -1281,7 +1292,7 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq) ...@@ -1281,7 +1292,7 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq)
if (!cfq_cfqq_prio_changed(cfqq)) if (!cfq_cfqq_prio_changed(cfqq))
return; return;
ioprio_class = IOPRIO_PRIO_CLASS(tsk->ioprio); ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio);
switch (ioprio_class) { switch (ioprio_class) {
default: default:
printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class);
...@@ -1293,11 +1304,11 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq) ...@@ -1293,11 +1304,11 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq)
cfqq->ioprio_class = IOPRIO_CLASS_BE; cfqq->ioprio_class = IOPRIO_CLASS_BE;
break; break;
case IOPRIO_CLASS_RT: case IOPRIO_CLASS_RT:
cfqq->ioprio = task_ioprio(tsk); cfqq->ioprio = task_ioprio(ioc);
cfqq->ioprio_class = IOPRIO_CLASS_RT; cfqq->ioprio_class = IOPRIO_CLASS_RT;
break; break;
case IOPRIO_CLASS_BE: case IOPRIO_CLASS_BE:
cfqq->ioprio = task_ioprio(tsk); cfqq->ioprio = task_ioprio(ioc);
cfqq->ioprio_class = IOPRIO_CLASS_BE; cfqq->ioprio_class = IOPRIO_CLASS_BE;
break; break;
case IOPRIO_CLASS_IDLE: case IOPRIO_CLASS_IDLE:
...@@ -1316,7 +1327,7 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq) ...@@ -1316,7 +1327,7 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq)
cfq_clear_cfqq_prio_changed(cfqq); cfq_clear_cfqq_prio_changed(cfqq);
} }
static inline void changed_ioprio(struct cfq_io_context *cic) static void changed_ioprio(struct io_context *ioc, struct cfq_io_context *cic)
{ {
struct cfq_data *cfqd = cic->key; struct cfq_data *cfqd = cic->key;
struct cfq_queue *cfqq; struct cfq_queue *cfqq;
...@@ -1330,8 +1341,7 @@ static inline void changed_ioprio(struct cfq_io_context *cic) ...@@ -1330,8 +1341,7 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
cfqq = cic->cfqq[ASYNC]; cfqq = cic->cfqq[ASYNC];
if (cfqq) { if (cfqq) {
struct cfq_queue *new_cfqq; struct cfq_queue *new_cfqq;
new_cfqq = cfq_get_queue(cfqd, ASYNC, cic->ioc->task, new_cfqq = cfq_get_queue(cfqd, ASYNC, cic->ioc, GFP_ATOMIC);
GFP_ATOMIC);
if (new_cfqq) { if (new_cfqq) {
cic->cfqq[ASYNC] = new_cfqq; cic->cfqq[ASYNC] = new_cfqq;
cfq_put_queue(cfqq); cfq_put_queue(cfqq);
...@@ -1347,29 +1357,19 @@ static inline void changed_ioprio(struct cfq_io_context *cic) ...@@ -1347,29 +1357,19 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
static void cfq_ioc_set_ioprio(struct io_context *ioc) static void cfq_ioc_set_ioprio(struct io_context *ioc)
{ {
struct cfq_io_context *cic; call_for_each_cic(ioc, changed_ioprio);
struct rb_node *n;
ioc->ioprio_changed = 0; ioc->ioprio_changed = 0;
n = rb_first(&ioc->cic_root);
while (n != NULL) {
cic = rb_entry(n, struct cfq_io_context, rb_node);
changed_ioprio(cic);
n = rb_next(n);
}
} }
static struct cfq_queue * static struct cfq_queue *
cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync, cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync,
struct task_struct *tsk, gfp_t gfp_mask) struct io_context *ioc, gfp_t gfp_mask)
{ {
struct cfq_queue *cfqq, *new_cfqq = NULL; struct cfq_queue *cfqq, *new_cfqq = NULL;
struct cfq_io_context *cic; struct cfq_io_context *cic;
retry: retry:
cic = cfq_cic_rb_lookup(cfqd, tsk->io_context); cic = cfq_cic_lookup(cfqd, ioc);
/* cic always exists here */ /* cic always exists here */
cfqq = cic_to_cfqq(cic, is_sync); cfqq = cic_to_cfqq(cic, is_sync);
...@@ -1404,15 +1404,16 @@ cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync, ...@@ -1404,15 +1404,16 @@ cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync,
atomic_set(&cfqq->ref, 0); atomic_set(&cfqq->ref, 0);
cfqq->cfqd = cfqd; cfqq->cfqd = cfqd;
cfq_mark_cfqq_prio_changed(cfqq);
cfq_mark_cfqq_queue_new(cfqq);
cfq_init_prio_data(cfqq, ioc);
if (is_sync) { if (is_sync) {
if (!cfq_class_idle(cfqq))
cfq_mark_cfqq_idle_window(cfqq); cfq_mark_cfqq_idle_window(cfqq);
cfq_mark_cfqq_sync(cfqq); cfq_mark_cfqq_sync(cfqq);
} }
cfq_mark_cfqq_prio_changed(cfqq);
cfq_mark_cfqq_queue_new(cfqq);
cfq_init_prio_data(cfqq);
} }
if (new_cfqq) if (new_cfqq)
...@@ -1439,11 +1440,11 @@ cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) ...@@ -1439,11 +1440,11 @@ cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio)
} }
static struct cfq_queue * static struct cfq_queue *
cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct task_struct *tsk, cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct io_context *ioc,
gfp_t gfp_mask) gfp_t gfp_mask)
{ {
const int ioprio = task_ioprio(tsk); const int ioprio = task_ioprio(ioc);
const int ioprio_class = task_ioprio_class(tsk); const int ioprio_class = task_ioprio_class(ioc);
struct cfq_queue **async_cfqq = NULL; struct cfq_queue **async_cfqq = NULL;
struct cfq_queue *cfqq = NULL; struct cfq_queue *cfqq = NULL;
...@@ -1453,7 +1454,7 @@ cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct task_struct *tsk, ...@@ -1453,7 +1454,7 @@ cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct task_struct *tsk,
} }
if (!cfqq) { if (!cfqq) {
cfqq = cfq_find_alloc_queue(cfqd, is_sync, tsk, gfp_mask); cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask);
if (!cfqq) if (!cfqq)
return NULL; return NULL;
} }
...@@ -1470,28 +1471,42 @@ cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct task_struct *tsk, ...@@ -1470,28 +1471,42 @@ cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct task_struct *tsk,
return cfqq; return cfqq;
} }
static void cfq_cic_free(struct cfq_io_context *cic)
{
kmem_cache_free(cfq_ioc_pool, cic);
elv_ioc_count_dec(ioc_count);
if (ioc_gone && !elv_ioc_count_read(ioc_count))
complete(ioc_gone);
}
/* /*
* We drop cfq io contexts lazily, so we may find a dead one. * We drop cfq io contexts lazily, so we may find a dead one.
*/ */
static void static void
cfq_drop_dead_cic(struct io_context *ioc, struct cfq_io_context *cic) cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc,
struct cfq_io_context *cic)
{ {
unsigned long flags;
WARN_ON(!list_empty(&cic->queue_list)); WARN_ON(!list_empty(&cic->queue_list));
spin_lock_irqsave(&ioc->lock, flags);
if (ioc->ioc_data == cic) if (ioc->ioc_data == cic)
ioc->ioc_data = NULL; rcu_assign_pointer(ioc->ioc_data, NULL);
rb_erase(&cic->rb_node, &ioc->cic_root); radix_tree_delete(&ioc->radix_root, (unsigned long) cfqd);
kmem_cache_free(cfq_ioc_pool, cic); spin_unlock_irqrestore(&ioc->lock, flags);
elv_ioc_count_dec(ioc_count);
cfq_cic_free(cic);
} }
static struct cfq_io_context * static struct cfq_io_context *
cfq_cic_rb_lookup(struct cfq_data *cfqd, struct io_context *ioc) cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc)
{ {
struct rb_node *n;
struct cfq_io_context *cic; struct cfq_io_context *cic;
void *k, *key = cfqd; void *k;
if (unlikely(!ioc)) if (unlikely(!ioc))
return NULL; return NULL;
...@@ -1499,74 +1514,64 @@ cfq_cic_rb_lookup(struct cfq_data *cfqd, struct io_context *ioc) ...@@ -1499,74 +1514,64 @@ cfq_cic_rb_lookup(struct cfq_data *cfqd, struct io_context *ioc)
/* /*
* we maintain a last-hit cache, to avoid browsing over the tree * we maintain a last-hit cache, to avoid browsing over the tree
*/ */
cic = ioc->ioc_data; cic = rcu_dereference(ioc->ioc_data);
if (cic && cic->key == cfqd) if (cic && cic->key == cfqd)
return cic; return cic;
restart: do {
n = ioc->cic_root.rb_node; rcu_read_lock();
while (n) { cic = radix_tree_lookup(&ioc->radix_root, (unsigned long) cfqd);
cic = rb_entry(n, struct cfq_io_context, rb_node); rcu_read_unlock();
if (!cic)
break;
/* ->key must be copied to avoid race with cfq_exit_queue() */ /* ->key must be copied to avoid race with cfq_exit_queue() */
k = cic->key; k = cic->key;
if (unlikely(!k)) { if (unlikely(!k)) {
cfq_drop_dead_cic(ioc, cic); cfq_drop_dead_cic(cfqd, ioc, cic);
goto restart; continue;
} }
if (key < k) rcu_assign_pointer(ioc->ioc_data, cic);
n = n->rb_left; break;
else if (key > k) } while (1);
n = n->rb_right;
else {
ioc->ioc_data = cic;
return cic;
}
}
return NULL; return cic;
} }
static inline void /*
cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, * Add cic into ioc, using cfqd as the search key. This enables us to lookup
struct cfq_io_context *cic) * the process specific cfq io context when entered from the block layer.
* Also adds the cic to a per-cfqd list, used when this queue is removed.
*/
static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc,
struct cfq_io_context *cic, gfp_t gfp_mask)
{ {
struct rb_node **p;
struct rb_node *parent;
struct cfq_io_context *__cic;
unsigned long flags; unsigned long flags;
void *k; int ret;
ret = radix_tree_preload(gfp_mask);
if (!ret) {
cic->ioc = ioc; cic->ioc = ioc;
cic->key = cfqd; cic->key = cfqd;
restart: spin_lock_irqsave(&ioc->lock, flags);
parent = NULL; ret = radix_tree_insert(&ioc->radix_root,
p = &ioc->cic_root.rb_node; (unsigned long) cfqd, cic);
while (*p) { spin_unlock_irqrestore(&ioc->lock, flags);
parent = *p;
__cic = rb_entry(parent, struct cfq_io_context, rb_node);
/* ->key must be copied to avoid race with cfq_exit_queue() */
k = __cic->key;
if (unlikely(!k)) {
cfq_drop_dead_cic(ioc, __cic);
goto restart;
}
if (cic->key < k)
p = &(*p)->rb_left;
else if (cic->key > k)
p = &(*p)->rb_right;
else
BUG();
}
rb_link_node(&cic->rb_node, parent, p); radix_tree_preload_end();
rb_insert_color(&cic->rb_node, &ioc->cic_root);
if (!ret) {
spin_lock_irqsave(cfqd->queue->queue_lock, flags); spin_lock_irqsave(cfqd->queue->queue_lock, flags);
list_add(&cic->queue_list, &cfqd->cic_list); list_add(&cic->queue_list, &cfqd->cic_list);
spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
}
}
if (ret)
printk(KERN_ERR "cfq: cic link failed!\n");
return ret;
} }
/* /*
...@@ -1586,7 +1591,7 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) ...@@ -1586,7 +1591,7 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
if (!ioc) if (!ioc)
return NULL; return NULL;
cic = cfq_cic_rb_lookup(cfqd, ioc); cic = cfq_cic_lookup(cfqd, ioc);
if (cic) if (cic)
goto out; goto out;
...@@ -1594,13 +1599,17 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) ...@@ -1594,13 +1599,17 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
if (cic == NULL) if (cic == NULL)
goto err; goto err;
cfq_cic_link(cfqd, ioc, cic); if (cfq_cic_link(cfqd, ioc, cic, gfp_mask))
goto err_free;
out: out:
smp_read_barrier_depends(); smp_read_barrier_depends();
if (unlikely(ioc->ioprio_changed)) if (unlikely(ioc->ioprio_changed))
cfq_ioc_set_ioprio(ioc); cfq_ioc_set_ioprio(ioc);
return cic; return cic;
err_free:
cfq_cic_free(cic);
err: err:
put_io_context(ioc); put_io_context(ioc);
return NULL; return NULL;
...@@ -1655,12 +1664,15 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, ...@@ -1655,12 +1664,15 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
{ {
int enable_idle; int enable_idle;
if (!cfq_cfqq_sync(cfqq)) /*
* Don't idle for async or idle io prio class
*/
if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq))
return; return;
enable_idle = cfq_cfqq_idle_window(cfqq); enable_idle = cfq_cfqq_idle_window(cfqq);
if (!cic->ioc->task || !cfqd->cfq_slice_idle || if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle ||
(cfqd->hw_tag && CIC_SEEKY(cic))) (cfqd->hw_tag && CIC_SEEKY(cic)))
enable_idle = 0; enable_idle = 0;
else if (sample_valid(cic->ttime_samples)) { else if (sample_valid(cic->ttime_samples)) {
...@@ -1793,7 +1805,7 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq) ...@@ -1793,7 +1805,7 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq)
struct cfq_data *cfqd = q->elevator->elevator_data; struct cfq_data *cfqd = q->elevator->elevator_data;
struct cfq_queue *cfqq = RQ_CFQQ(rq); struct cfq_queue *cfqq = RQ_CFQQ(rq);
cfq_init_prio_data(cfqq); cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc);
cfq_add_rq_rb(rq); cfq_add_rq_rb(rq);
...@@ -1834,7 +1846,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq) ...@@ -1834,7 +1846,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
cfq_set_prio_slice(cfqd, cfqq); cfq_set_prio_slice(cfqd, cfqq);
cfq_clear_cfqq_slice_new(cfqq); cfq_clear_cfqq_slice_new(cfqq);
} }
if (cfq_slice_used(cfqq)) if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq))
cfq_slice_expired(cfqd, 1); cfq_slice_expired(cfqd, 1);
else if (sync && RB_EMPTY_ROOT(&cfqq->sort_list)) else if (sync && RB_EMPTY_ROOT(&cfqq->sort_list))
cfq_arm_slice_timer(cfqd); cfq_arm_slice_timer(cfqd);
...@@ -1894,13 +1906,13 @@ static int cfq_may_queue(struct request_queue *q, int rw) ...@@ -1894,13 +1906,13 @@ static int cfq_may_queue(struct request_queue *q, int rw)
* so just lookup a possibly existing queue, or return 'may queue' * so just lookup a possibly existing queue, or return 'may queue'
* if that fails * if that fails
*/ */
cic = cfq_cic_rb_lookup(cfqd, tsk->io_context); cic = cfq_cic_lookup(cfqd, tsk->io_context);
if (!cic) if (!cic)
return ELV_MQUEUE_MAY; return ELV_MQUEUE_MAY;
cfqq = cic_to_cfqq(cic, rw & REQ_RW_SYNC); cfqq = cic_to_cfqq(cic, rw & REQ_RW_SYNC);
if (cfqq) { if (cfqq) {
cfq_init_prio_data(cfqq); cfq_init_prio_data(cfqq, cic->ioc);
cfq_prio_boost(cfqq); cfq_prio_boost(cfqq);
return __cfq_may_queue(cfqq); return __cfq_may_queue(cfqq);
...@@ -1938,7 +1950,6 @@ static int ...@@ -1938,7 +1950,6 @@ static int
cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
{ {
struct cfq_data *cfqd = q->elevator->elevator_data; struct cfq_data *cfqd = q->elevator->elevator_data;
struct task_struct *tsk = current;
struct cfq_io_context *cic; struct cfq_io_context *cic;
const int rw = rq_data_dir(rq); const int rw = rq_data_dir(rq);
const int is_sync = rq_is_sync(rq); const int is_sync = rq_is_sync(rq);
...@@ -1956,7 +1967,7 @@ cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) ...@@ -1956,7 +1967,7 @@ cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
cfqq = cic_to_cfqq(cic, is_sync); cfqq = cic_to_cfqq(cic, is_sync);
if (!cfqq) { if (!cfqq) {
cfqq = cfq_get_queue(cfqd, is_sync, tsk, gfp_mask); cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask);
if (!cfqq) if (!cfqq)
goto queue_fail; goto queue_fail;
...@@ -2039,29 +2050,9 @@ static void cfq_idle_slice_timer(unsigned long data) ...@@ -2039,29 +2050,9 @@ static void cfq_idle_slice_timer(unsigned long data)
spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
} }
/*
* Timer running if an idle class queue is waiting for service
*/
static void cfq_idle_class_timer(unsigned long data)
{
struct cfq_data *cfqd = (struct cfq_data *) data;
unsigned long flags;
spin_lock_irqsave(cfqd->queue->queue_lock, flags);
/*
* race with a non-idle queue, reset timer
*/
if (!start_idle_class_timer(cfqd))
cfq_schedule_dispatch(cfqd);
spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
}
static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) static void cfq_shutdown_timer_wq(struct cfq_data *cfqd)
{ {
del_timer_sync(&cfqd->idle_slice_timer); del_timer_sync(&cfqd->idle_slice_timer);
del_timer_sync(&cfqd->idle_class_timer);
kblockd_flush_work(&cfqd->unplug_work); kblockd_flush_work(&cfqd->unplug_work);
} }
...@@ -2126,10 +2117,6 @@ static void *cfq_init_queue(struct request_queue *q) ...@@ -2126,10 +2117,6 @@ static void *cfq_init_queue(struct request_queue *q)
cfqd->idle_slice_timer.function = cfq_idle_slice_timer; cfqd->idle_slice_timer.function = cfq_idle_slice_timer;
cfqd->idle_slice_timer.data = (unsigned long) cfqd; cfqd->idle_slice_timer.data = (unsigned long) cfqd;
init_timer(&cfqd->idle_class_timer);
cfqd->idle_class_timer.function = cfq_idle_class_timer;
cfqd->idle_class_timer.data = (unsigned long) cfqd;
INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); INIT_WORK(&cfqd->unplug_work, cfq_kick_queue);
cfqd->last_end_request = jiffies; cfqd->last_end_request = jiffies;
...@@ -2160,7 +2147,7 @@ static int __init cfq_slab_setup(void) ...@@ -2160,7 +2147,7 @@ static int __init cfq_slab_setup(void)
if (!cfq_pool) if (!cfq_pool)
goto fail; goto fail;
cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0); cfq_ioc_pool = KMEM_CACHE(cfq_io_context, SLAB_DESTROY_BY_RCU);
if (!cfq_ioc_pool) if (!cfq_ioc_pool)
goto fail; goto fail;
......
...@@ -3853,55 +3853,100 @@ int __init blk_dev_init(void) ...@@ -3853,55 +3853,100 @@ int __init blk_dev_init(void)
return 0; return 0;
} }
static void cfq_dtor(struct io_context *ioc)
{
struct cfq_io_context *cic[1];
int r;
/*
* We don't have a specific key to lookup with, so use the gang
* lookup to just retrieve the first item stored. The cfq exit
* function will iterate the full tree, so any member will do.
*/
r = radix_tree_gang_lookup(&ioc->radix_root, (void **) cic, 0, 1);
if (r > 0)
cic[0]->dtor(ioc);
}
/* /*
* IO Context helper functions * IO Context helper functions. put_io_context() returns 1 if there are no
* more users of this io context, 0 otherwise.
*/ */
void put_io_context(struct io_context *ioc) int put_io_context(struct io_context *ioc)
{ {
if (ioc == NULL) if (ioc == NULL)
return; return 1;
BUG_ON(atomic_read(&ioc->refcount) == 0); BUG_ON(atomic_read(&ioc->refcount) == 0);
if (atomic_dec_and_test(&ioc->refcount)) { if (atomic_dec_and_test(&ioc->refcount)) {
struct cfq_io_context *cic;
rcu_read_lock(); rcu_read_lock();
if (ioc->aic && ioc->aic->dtor) if (ioc->aic && ioc->aic->dtor)
ioc->aic->dtor(ioc->aic); ioc->aic->dtor(ioc->aic);
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(); rcu_read_unlock();
cfq_dtor(ioc);
kmem_cache_free(iocontext_cachep, ioc); kmem_cache_free(iocontext_cachep, ioc);
return 1;
} }
return 0;
} }
EXPORT_SYMBOL(put_io_context); EXPORT_SYMBOL(put_io_context);
static void cfq_exit(struct io_context *ioc)
{
struct cfq_io_context *cic[1];
int r;
rcu_read_lock();
/*
* See comment for cfq_dtor()
*/
r = radix_tree_gang_lookup(&ioc->radix_root, (void **) cic, 0, 1);
rcu_read_unlock();
if (r > 0)
cic[0]->exit(ioc);
}
/* Called by the exitting task */ /* Called by the exitting task */
void exit_io_context(void) void exit_io_context(void)
{ {
struct io_context *ioc; struct io_context *ioc;
struct cfq_io_context *cic;
task_lock(current); task_lock(current);
ioc = current->io_context; ioc = current->io_context;
current->io_context = NULL; current->io_context = NULL;
task_unlock(current); task_unlock(current);
ioc->task = NULL; if (atomic_dec_and_test(&ioc->nr_tasks)) {
if (ioc->aic && ioc->aic->exit) if (ioc->aic && ioc->aic->exit)
ioc->aic->exit(ioc->aic); ioc->aic->exit(ioc->aic);
if (ioc->cic_root.rb_node != NULL) { cfq_exit(ioc);
cic = rb_entry(rb_first(&ioc->cic_root), struct cfq_io_context, rb_node);
cic->exit(ioc);
}
put_io_context(ioc); put_io_context(ioc);
}
}
struct io_context *alloc_io_context(gfp_t gfp_flags, int node)
{
struct io_context *ret;
ret = kmem_cache_alloc_node(iocontext_cachep, gfp_flags, node);
if (ret) {
atomic_set(&ret->refcount, 1);
atomic_set(&ret->nr_tasks, 1);
spin_lock_init(&ret->lock);
ret->ioprio_changed = 0;
ret->ioprio = 0;
ret->last_waited = jiffies; /* doesn't matter... */
ret->nr_batch_requests = 0; /* because this is 0 */
ret->aic = NULL;
INIT_RADIX_TREE(&ret->radix_root, GFP_ATOMIC | __GFP_HIGH);
ret->ioc_data = NULL;
}
return ret;
} }
/* /*
...@@ -3921,16 +3966,8 @@ static struct io_context *current_io_context(gfp_t gfp_flags, int node) ...@@ -3921,16 +3966,8 @@ static struct io_context *current_io_context(gfp_t gfp_flags, int node)
if (likely(ret)) if (likely(ret))
return ret; return ret;
ret = kmem_cache_alloc_node(iocontext_cachep, gfp_flags, node); ret = alloc_io_context(gfp_flags, node);
if (ret) { if (ret) {
atomic_set(&ret->refcount, 1);
ret->task = current;
ret->ioprio_changed = 0;
ret->last_waited = jiffies; /* doesn't matter... */
ret->nr_batch_requests = 0; /* because this is 0 */
ret->aic = NULL;
ret->cic_root.rb_node = NULL;
ret->ioc_data = NULL;
/* make sure set_task_ioprio() sees the settings above */ /* make sure set_task_ioprio() sees the settings above */
smp_wmb(); smp_wmb();
tsk->io_context = ret; tsk->io_context = ret;
...@@ -3947,10 +3984,18 @@ static struct io_context *current_io_context(gfp_t gfp_flags, int node) ...@@ -3947,10 +3984,18 @@ static struct io_context *current_io_context(gfp_t gfp_flags, int node)
*/ */
struct io_context *get_io_context(gfp_t gfp_flags, int node) struct io_context *get_io_context(gfp_t gfp_flags, int node)
{ {
struct io_context *ret; struct io_context *ret = NULL;
/*
* Check for unlikely race with exiting task. ioc ref count is
* zero when ioc is being detached.
*/
do {
ret = current_io_context(gfp_flags, node); ret = current_io_context(gfp_flags, node);
if (likely(ret)) if (unlikely(!ret))
atomic_inc(&ret->refcount); break;
} while (!atomic_inc_not_zero(&ret->refcount));
return ret; return ret;
} }
EXPORT_SYMBOL(get_io_context); EXPORT_SYMBOL(get_io_context);
......
...@@ -41,18 +41,28 @@ static int set_task_ioprio(struct task_struct *task, int ioprio) ...@@ -41,18 +41,28 @@ static int set_task_ioprio(struct task_struct *task, int ioprio)
return err; return err;
task_lock(task); task_lock(task);
do {
task->ioprio = ioprio;
ioc = task->io_context; ioc = task->io_context;
/* see wmb() in current_io_context() */ /* see wmb() in current_io_context() */
smp_read_barrier_depends(); smp_read_barrier_depends();
if (ioc) if (ioc)
break;
ioc = alloc_io_context(GFP_ATOMIC, -1);
if (!ioc) {
err = -ENOMEM;
break;
}
task->io_context = ioc;
} while (1);
if (!err) {
ioc->ioprio = ioprio;
ioc->ioprio_changed = 1; ioc->ioprio_changed = 1;
}
task_unlock(task); task_unlock(task);
return 0; return err;
} }
asmlinkage long sys_ioprio_set(int which, int who, int ioprio) asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
...@@ -75,8 +85,6 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio) ...@@ -75,8 +85,6 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
break; break;
case IOPRIO_CLASS_IDLE: case IOPRIO_CLASS_IDLE:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
break; break;
case IOPRIO_CLASS_NONE: case IOPRIO_CLASS_NONE:
if (data) if (data)
...@@ -148,7 +156,9 @@ static int get_task_ioprio(struct task_struct *p) ...@@ -148,7 +156,9 @@ static int get_task_ioprio(struct task_struct *p)
ret = security_task_getioprio(p); ret = security_task_getioprio(p);
if (ret) if (ret)
goto out; goto out;
ret = p->ioprio; ret = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, IOPRIO_NORM);
if (p->io_context)
ret = p->io_context->ioprio;
out: out:
return ret; return ret;
} }
......
...@@ -34,83 +34,10 @@ struct sg_io_hdr; ...@@ -34,83 +34,10 @@ struct sg_io_hdr;
#define BLKDEV_MIN_RQ 4 #define BLKDEV_MIN_RQ 4
#define BLKDEV_MAX_RQ 128 /* Default maximum */ #define BLKDEV_MAX_RQ 128 /* Default maximum */
/* int put_io_context(struct io_context *ioc);
* This is the per-process anticipatory I/O scheduler state.
*/
struct as_io_context {
spinlock_t lock;
void (*dtor)(struct as_io_context *aic); /* destructor */
void (*exit)(struct as_io_context *aic); /* called on task exit */
unsigned long state;
atomic_t nr_queued; /* queued reads & sync writes */
atomic_t nr_dispatched; /* number of requests gone to the drivers */
/* IO History tracking */
/* Thinktime */
unsigned long last_end_request;
unsigned long ttime_total;
unsigned long ttime_samples;
unsigned long ttime_mean;
/* Layout pattern */
unsigned int seek_samples;
sector_t last_request_pos;
u64 seek_total;
sector_t seek_mean;
};
struct cfq_queue;
struct cfq_io_context {
struct rb_node rb_node;
void *key;
struct cfq_queue *cfqq[2];
struct io_context *ioc;
unsigned long last_end_request;
sector_t last_request_pos;
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 io_context *); /* destructor */
void (*exit)(struct io_context *); /* called on task exit */
};
/*
* This is the per-process I/O subsystem state. It is refcounted and
* kmalloc'ed. Currently all fields are modified in process io context
* (apart from the atomic refcount), so require no locking.
*/
struct io_context {
atomic_t refcount;
struct task_struct *task;
unsigned int ioprio_changed;
/*
* For request batching
*/
unsigned long last_waited; /* Time last woken after wait for request */
int nr_batch_requests; /* Number of requests left in the batch */
struct as_io_context *aic;
struct rb_root cic_root;
void *ioc_data;
};
void put_io_context(struct io_context *ioc);
void exit_io_context(void); void exit_io_context(void);
struct io_context *get_io_context(gfp_t gfp_flags, int node); struct io_context *get_io_context(gfp_t gfp_flags, int node);
struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
void copy_io_context(struct io_context **pdst, struct io_context **psrc); void copy_io_context(struct io_context **pdst, struct io_context **psrc);
void swap_io_context(struct io_context **ioc1, struct io_context **ioc2); void swap_io_context(struct io_context **ioc1, struct io_context **ioc2);
...@@ -894,6 +821,12 @@ static inline void exit_io_context(void) ...@@ -894,6 +821,12 @@ static inline void exit_io_context(void)
{ {
} }
static inline int put_io_context(struct io_context *ioc)
{
return 1;
}
#endif /* CONFIG_BLOCK */ #endif /* CONFIG_BLOCK */
#endif #endif
...@@ -137,7 +137,6 @@ extern struct group_info init_groups; ...@@ -137,7 +137,6 @@ extern struct group_info init_groups;
.time_slice = HZ, \ .time_slice = HZ, \
.nr_cpus_allowed = NR_CPUS, \ .nr_cpus_allowed = NR_CPUS, \
}, \ }, \
.ioprio = 0, \
.tasks = LIST_HEAD_INIT(tsk.tasks), \ .tasks = LIST_HEAD_INIT(tsk.tasks), \
.ptrace_children= LIST_HEAD_INIT(tsk.ptrace_children), \ .ptrace_children= LIST_HEAD_INIT(tsk.ptrace_children), \
.ptrace_list = LIST_HEAD_INIT(tsk.ptrace_list), \ .ptrace_list = LIST_HEAD_INIT(tsk.ptrace_list), \
......
#ifndef IOCONTEXT_H
#define IOCONTEXT_H
#include <linux/radix-tree.h>
/*
* This is the per-process anticipatory I/O scheduler state.
*/
struct as_io_context {
spinlock_t lock;
void (*dtor)(struct as_io_context *aic); /* destructor */
void (*exit)(struct as_io_context *aic); /* called on task exit */
unsigned long state;
atomic_t nr_queued; /* queued reads & sync writes */
atomic_t nr_dispatched; /* number of requests gone to the drivers */
/* IO History tracking */
/* Thinktime */
unsigned long last_end_request;
unsigned long ttime_total;
unsigned long ttime_samples;
unsigned long ttime_mean;
/* Layout pattern */
unsigned int seek_samples;
sector_t last_request_pos;
u64 seek_total;
sector_t seek_mean;
};
struct cfq_queue;
struct cfq_io_context {
void *key;
unsigned long dead_key;
struct cfq_queue *cfqq[2];
struct io_context *ioc;
unsigned long last_end_request;
sector_t last_request_pos;
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 io_context *); /* destructor */
void (*exit)(struct io_context *); /* called on task exit */
};
/*
* I/O subsystem state of the associated processes. It is refcounted
* and kmalloc'ed. These could be shared between processes.
*/
struct io_context {
atomic_t refcount;
atomic_t nr_tasks;
/* all the fields below are protected by this lock */
spinlock_t lock;
unsigned short ioprio;
unsigned short ioprio_changed;
/*
* For request batching
*/
unsigned long last_waited; /* Time last woken after wait for request */
int nr_batch_requests; /* Number of requests left in the batch */
struct as_io_context *aic;
struct radix_tree_root radix_root;
void *ioc_data;
};
static inline struct io_context *ioc_task_link(struct io_context *ioc)
{
/*
* if ref count is zero, don't allow sharing (ioc is going away, it's
* a race).
*/
if (ioc && atomic_inc_not_zero(&ioc->refcount))
return ioc;
return NULL;
}
#endif
...@@ -2,6 +2,7 @@ ...@@ -2,6 +2,7 @@
#define IOPRIO_H #define IOPRIO_H
#include <linux/sched.h> #include <linux/sched.h>
#include <linux/iocontext.h>
/* /*
* Gives us 8 prio classes with 13-bits of data for each class * Gives us 8 prio classes with 13-bits of data for each class
...@@ -45,18 +46,18 @@ enum { ...@@ -45,18 +46,18 @@ enum {
* the cpu scheduler nice value to an io priority * the cpu scheduler nice value to an io priority
*/ */
#define IOPRIO_NORM (4) #define IOPRIO_NORM (4)
static inline int task_ioprio(struct task_struct *task) static inline int task_ioprio(struct io_context *ioc)
{ {
if (ioprio_valid(task->ioprio)) if (ioprio_valid(ioc->ioprio))
return IOPRIO_PRIO_DATA(task->ioprio); return IOPRIO_PRIO_DATA(ioc->ioprio);
return IOPRIO_NORM; return IOPRIO_NORM;
} }
static inline int task_ioprio_class(struct task_struct *task) static inline int task_ioprio_class(struct io_context *ioc)
{ {
if (ioprio_valid(task->ioprio)) if (ioprio_valid(ioc->ioprio))
return IOPRIO_PRIO_CLASS(task->ioprio); return IOPRIO_PRIO_CLASS(ioc->ioprio);
return IOPRIO_CLASS_BE; return IOPRIO_CLASS_BE;
} }
......
...@@ -27,6 +27,7 @@ ...@@ -27,6 +27,7 @@
#define CLONE_NEWUSER 0x10000000 /* New user namespace */ #define CLONE_NEWUSER 0x10000000 /* New user namespace */
#define CLONE_NEWPID 0x20000000 /* New pid namespace */ #define CLONE_NEWPID 0x20000000 /* New pid namespace */
#define CLONE_NEWNET 0x40000000 /* New network namespace */ #define CLONE_NEWNET 0x40000000 /* New network namespace */
#define CLONE_IO 0x80000000 /* Clone io context */
/* /*
* Scheduling policies * Scheduling policies
...@@ -975,7 +976,6 @@ struct task_struct { ...@@ -975,7 +976,6 @@ struct task_struct {
struct hlist_head preempt_notifiers; struct hlist_head preempt_notifiers;
#endif #endif
unsigned short ioprio;
/* /*
* fpu_counter contains the number of consecutive context switches * fpu_counter contains the number of consecutive context switches
* that the FPU is used. If this is over a threshold, the lazy fpu * that the FPU is used. If this is over a threshold, the lazy fpu
......
...@@ -51,6 +51,7 @@ ...@@ -51,6 +51,7 @@
#include <linux/random.h> #include <linux/random.h>
#include <linux/tty.h> #include <linux/tty.h>
#include <linux/proc_fs.h> #include <linux/proc_fs.h>
#include <linux/blkdev.h>
#include <asm/pgtable.h> #include <asm/pgtable.h>
#include <asm/pgalloc.h> #include <asm/pgalloc.h>
...@@ -791,6 +792,31 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk) ...@@ -791,6 +792,31 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
return error; return error;
} }
static int copy_io(unsigned long clone_flags, struct task_struct *tsk)
{
#ifdef CONFIG_BLOCK
struct io_context *ioc = current->io_context;
if (!ioc)
return 0;
/*
* Share io context with parent, if CLONE_IO is set
*/
if (clone_flags & CLONE_IO) {
tsk->io_context = ioc_task_link(ioc);
if (unlikely(!tsk->io_context))
return -ENOMEM;
} else if (ioprio_valid(ioc->ioprio)) {
tsk->io_context = alloc_io_context(GFP_KERNEL, -1);
if (unlikely(!tsk->io_context))
return -ENOMEM;
tsk->io_context->ioprio = ioc->ioprio;
}
#endif
return 0;
}
/* /*
* Helper to unshare the files of the current task. * Helper to unshare the files of the current task.
* We don't want to expose copy_files internals to * We don't want to expose copy_files internals to
...@@ -1156,15 +1182,17 @@ static struct task_struct *copy_process(unsigned long clone_flags, ...@@ -1156,15 +1182,17 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto bad_fork_cleanup_mm; goto bad_fork_cleanup_mm;
if ((retval = copy_namespaces(clone_flags, p))) if ((retval = copy_namespaces(clone_flags, p)))
goto bad_fork_cleanup_keys; goto bad_fork_cleanup_keys;
if ((retval = copy_io(clone_flags, p)))
goto bad_fork_cleanup_namespaces;
retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs); retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
if (retval) if (retval)
goto bad_fork_cleanup_namespaces; goto bad_fork_cleanup_io;
if (pid != &init_struct_pid) { if (pid != &init_struct_pid) {
retval = -ENOMEM; retval = -ENOMEM;
pid = alloc_pid(task_active_pid_ns(p)); pid = alloc_pid(task_active_pid_ns(p));
if (!pid) if (!pid)
goto bad_fork_cleanup_namespaces; goto bad_fork_cleanup_io;
if (clone_flags & CLONE_NEWPID) { if (clone_flags & CLONE_NEWPID) {
retval = pid_ns_prepare_proc(task_active_pid_ns(p)); retval = pid_ns_prepare_proc(task_active_pid_ns(p));
...@@ -1234,9 +1262,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, ...@@ -1234,9 +1262,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
/* Need tasklist lock for parent etc handling! */ /* Need tasklist lock for parent etc handling! */
write_lock_irq(&tasklist_lock); write_lock_irq(&tasklist_lock);
/* for sys_ioprio_set(IOPRIO_WHO_PGRP) */
p->ioprio = current->ioprio;
/* /*
* The task hasn't been attached yet, so its cpus_allowed mask will * The task hasn't been attached yet, so its cpus_allowed mask will
* not be changed, nor will its assigned CPU. * not be changed, nor will its assigned CPU.
...@@ -1328,6 +1353,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, ...@@ -1328,6 +1353,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
bad_fork_free_pid: bad_fork_free_pid:
if (pid != &init_struct_pid) if (pid != &init_struct_pid)
free_pid(pid); free_pid(pid);
bad_fork_cleanup_io:
put_io_context(p->io_context);
bad_fork_cleanup_namespaces: bad_fork_cleanup_namespaces:
exit_task_namespaces(p); exit_task_namespaces(p);
bad_fork_cleanup_keys: bad_fork_cleanup_keys:
......
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