diff --git a/block/as-iosched.c b/block/as-iosched.c
index cb5e53b05c7c6baf6224f36a2c3dee8528c4e116..b201d16a71020f1261a42bc56ac36a9915da16ad 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -170,9 +170,11 @@ static void free_as_io_context(struct as_io_context *aic)
static void as_trim(struct io_context *ioc)
{
+ spin_lock(&ioc->lock);
if (ioc->aic)
free_as_io_context(ioc->aic);
ioc->aic = NULL;
+ spin_unlock(&ioc->lock);
}
/* Called when the task exits */
@@ -462,7 +464,9 @@ static void as_antic_timeout(unsigned long data)
spin_lock_irqsave(q->queue_lock, flags);
if (ad->antic_status == ANTIC_WAIT_REQ
|| 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;
kblockd_schedule_work(&ad->antic_work);
@@ -475,6 +479,7 @@ static void as_antic_timeout(unsigned long data)
/* process not "saved" by a cooperating request */
ad->exit_no_coop = (7*ad->exit_no_coop + 256)/8;
}
+ spin_unlock(&ad->io_context->lock);
}
spin_unlock_irqrestore(q->queue_lock, flags);
}
@@ -635,9 +640,11 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
ioc = ad->io_context;
BUG_ON(!ioc);
+ spin_lock(&ioc->lock);
if (rq && ioc == RQ_IOC(rq)) {
/* request from same process */
+ spin_unlock(&ioc->lock);
return 1;
}
@@ -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,
* however the timer hasn't had the chance to run yet.
*/
+ spin_unlock(&ioc->lock);
return 1;
}
aic = ioc->aic;
- if (!aic)
+ if (!aic) {
+ spin_unlock(&ioc->lock);
return 0;
+ }
if (atomic_read(&aic->nr_queued) > 0) {
/* process has more requests queued */
+ spin_unlock(&ioc->lock);
return 1;
}
if (atomic_read(&aic->nr_dispatched) > 0) {
/* process has more requests dispatched */
+ spin_unlock(&ioc->lock);
return 1;
}
@@ -680,6 +692,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
}
as_update_iohist(ad, aic, rq);
+ spin_unlock(&ioc->lock);
return 1;
}
@@ -688,20 +701,27 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
if (aic->ttime_samples == 0)
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;
+ }
}
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;
- 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;
+ }
} else if (aic->ttime_mean > ad->antic_expire) {
/* the process thinks too much between requests */
+ spin_unlock(&ioc->lock);
return 1;
}
-
+ spin_unlock(&ioc->lock);
return 0;
}
@@ -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
* removed below, it must contain the unused context
*/
+ double_spin_lock(&rioc->lock, &nioc->lock, rioc < nioc);
swap_io_context(&rioc, &nioc);
+ double_spin_unlock(&rioc->lock, &nioc->lock, rioc < nioc);
}
}
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 13553e015d7203f244db2e411884c56cbee1bc26..f28d1fb30608cd5667b6b6f9c67e545bdb4802de 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -26,9 +26,9 @@ static const int cfq_slice_async_rq = 2;
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
@@ -98,8 +98,6 @@ struct cfq_data {
struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR];
struct cfq_queue *async_idle_cfqq;
- struct timer_list idle_class_timer;
-
sector_t last_position;
unsigned long last_end_request;
@@ -199,8 +197,8 @@ CFQ_CFQQ_FNS(sync);
static void cfq_dispatch_insert(struct request_queue *, struct request *);
static struct cfq_queue *cfq_get_queue(struct cfq_data *, int,
- struct task_struct *, gfp_t);
-static struct cfq_io_context *cfq_cic_rb_lookup(struct cfq_data *,
+ struct io_context *, gfp_t);
+static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *,
struct io_context *);
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)
/*
* 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)
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)
@@ -446,12 +447,20 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd,
static void cfq_service_tree_add(struct cfq_data *cfqd,
struct cfq_queue *cfqq, int add_front)
{
- struct rb_node **p = &cfqd->service_tree.rb.rb_node;
- struct rb_node *parent = NULL;
+ struct rb_node **p, *parent;
+ struct cfq_queue *__cfqq;
unsigned long rb_key;
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 += cfqq->slice_resid;
cfqq->slice_resid = 0;
@@ -469,8 +478,9 @@ static void cfq_service_tree_add(struct cfq_data *cfqd,
}
left = 1;
+ parent = NULL;
+ p = &cfqd->service_tree.rb.rb_node;
while (*p) {
- struct cfq_queue *__cfqq;
struct rb_node **n;
parent = *p;
@@ -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
* the pending list according to last request service
*/
-static inline void
-cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
BUG_ON(cfq_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)
* Called when the cfqq no longer has requests pending, remove it from
* the service tree.
*/
-static inline void
-cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
BUG_ON(!cfq_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)
/*
* 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_data *cfqd = cfqq->cfqd;
@@ -594,8 +602,7 @@ static void cfq_add_rq_rb(struct request *rq)
BUG_ON(!cfqq->next_rq);
}
-static inline void
-cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
+static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq)
{
elv_rb_del(&cfqq->sort_list, rq);
cfqq->queued[rq_is_sync(rq)]--;
@@ -609,7 +616,7 @@ cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio)
struct cfq_io_context *cic;
struct cfq_queue *cfqq;
- cic = cfq_cic_rb_lookup(cfqd, tsk->io_context);
+ cic = cfq_cic_lookup(cfqd, tsk->io_context);
if (!cic)
return NULL;
@@ -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
* 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)
return 0;
@@ -732,15 +739,10 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq,
return 0;
}
-static inline void
-__cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+static void __cfq_set_active_queue(struct cfq_data *cfqd,
+ struct cfq_queue *cfqq)
{
if (cfqq) {
- /*
- * stop potential idle class queues waiting service
- */
- del_timer(&cfqd->idle_class_timer);
-
cfqq->slice_end = 0;
cfq_clear_cfqq_must_alloc_slice(cfqq);
cfq_clear_cfqq_fifo_expire(cfqq);
@@ -789,47 +791,16 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, int 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,
* we'll simply select the first cfqq in the service tree.
*/
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))
return NULL;
- n = 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;
+ return cfq_rb_first(&cfqd->service_tree);
}
/*
@@ -895,7 +866,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
* task has exited, don't wait
*/
cic = cfqd->active_cic;
- if (!cic || !cic->ioc->task)
+ if (!cic || !atomic_read(&cic->ioc->nr_tasks))
return;
/*
@@ -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
*/
-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 request *rq;
@@ -1068,7 +1039,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
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;
@@ -1087,14 +1058,11 @@ static inline int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq)
*/
static int cfq_forced_dispatch(struct cfq_data *cfqd)
{
+ struct cfq_queue *cfqq;
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);
- }
cfq_slice_expired(cfqd, 0);
@@ -1170,20 +1138,69 @@ static void cfq_put_queue(struct cfq_queue *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 rb_node *n;
- int freed = 0;
+ struct cfq_io_context *cics[CIC_GANG_NR];
+ unsigned long index = 0;
+ unsigned int called = 0;
+ int nr;
- ioc->ioc_data = NULL;
+ rcu_read_lock();
- 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++;
- }
+ do {
+ int i;
+
+ /*
+ * 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);
@@ -1205,7 +1222,12 @@ static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
struct cfq_io_context *cic)
{
list_del_init(&cic->queue_list);
+
+ /*
+ * Make sure key == NULL is seen for dead queues
+ */
smp_wmb();
+ cic->dead_key = (unsigned long) cic->key;
cic->key = NULL;
if (cic->cfqq[ASYNC]) {
@@ -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;
if (cfqd) {
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);
- 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)
*/
static void cfq_exit_io_context(struct io_context *ioc)
{
- struct cfq_io_context *__cic;
- struct rb_node *n;
-
- 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);
- }
+ rcu_assign_pointer(ioc->ioc_data, NULL);
+ call_for_each_cic(ioc, cfq_exit_single_io_context);
}
static struct cfq_io_context *
@@ -1273,7 +1284,7 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
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;
int ioprio_class;
@@ -1281,7 +1292,7 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq)
if (!cfq_cfqq_prio_changed(cfqq))
return;
- ioprio_class = IOPRIO_PRIO_CLASS(tsk->ioprio);
+ ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio);
switch (ioprio_class) {
default:
printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class);
@@ -1293,11 +1304,11 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq)
cfqq->ioprio_class = IOPRIO_CLASS_BE;
break;
case IOPRIO_CLASS_RT:
- cfqq->ioprio = task_ioprio(tsk);
+ cfqq->ioprio = task_ioprio(ioc);
cfqq->ioprio_class = IOPRIO_CLASS_RT;
break;
case IOPRIO_CLASS_BE:
- cfqq->ioprio = task_ioprio(tsk);
+ cfqq->ioprio = task_ioprio(ioc);
cfqq->ioprio_class = IOPRIO_CLASS_BE;
break;
case IOPRIO_CLASS_IDLE:
@@ -1316,7 +1327,7 @@ static void cfq_init_prio_data(struct cfq_queue *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_queue *cfqq;
@@ -1330,8 +1341,7 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
cfqq = cic->cfqq[ASYNC];
if (cfqq) {
struct cfq_queue *new_cfqq;
- new_cfqq = cfq_get_queue(cfqd, ASYNC, cic->ioc->task,
- GFP_ATOMIC);
+ new_cfqq = cfq_get_queue(cfqd, ASYNC, cic->ioc, GFP_ATOMIC);
if (new_cfqq) {
cic->cfqq[ASYNC] = new_cfqq;
cfq_put_queue(cfqq);
@@ -1347,29 +1357,19 @@ static inline void changed_ioprio(struct cfq_io_context *cic)
static void cfq_ioc_set_ioprio(struct io_context *ioc)
{
- struct cfq_io_context *cic;
- struct rb_node *n;
-
+ call_for_each_cic(ioc, changed_ioprio);
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 *
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_io_context *cic;
retry:
- cic = cfq_cic_rb_lookup(cfqd, tsk->io_context);
+ cic = cfq_cic_lookup(cfqd, ioc);
/* cic always exists here */
cfqq = cic_to_cfqq(cic, is_sync);
@@ -1404,15 +1404,16 @@ cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync,
atomic_set(&cfqq->ref, 0);
cfqq->cfqd = cfqd;
- if (is_sync) {
- cfq_mark_cfqq_idle_window(cfqq);
- cfq_mark_cfqq_sync(cfqq);
- }
-
cfq_mark_cfqq_prio_changed(cfqq);
cfq_mark_cfqq_queue_new(cfqq);
- cfq_init_prio_data(cfqq);
+ cfq_init_prio_data(cfqq, ioc);
+
+ if (is_sync) {
+ if (!cfq_class_idle(cfqq))
+ cfq_mark_cfqq_idle_window(cfqq);
+ cfq_mark_cfqq_sync(cfqq);
+ }
}
if (new_cfqq)
@@ -1439,11 +1440,11 @@ cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio)
}
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)
{
- const int ioprio = task_ioprio(tsk);
- const int ioprio_class = task_ioprio_class(tsk);
+ const int ioprio = task_ioprio(ioc);
+ const int ioprio_class = task_ioprio_class(ioc);
struct cfq_queue **async_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,
}
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)
return NULL;
}
@@ -1470,28 +1471,42 @@ cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct task_struct *tsk,
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.
*/
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));
+ spin_lock_irqsave(&ioc->lock, flags);
+
if (ioc->ioc_data == cic)
- ioc->ioc_data = NULL;
+ rcu_assign_pointer(ioc->ioc_data, NULL);
- rb_erase(&cic->rb_node, &ioc->cic_root);
- kmem_cache_free(cfq_ioc_pool, cic);
- elv_ioc_count_dec(ioc_count);
+ radix_tree_delete(&ioc->radix_root, (unsigned long) cfqd);
+ spin_unlock_irqrestore(&ioc->lock, flags);
+
+ cfq_cic_free(cic);
}
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;
- void *k, *key = cfqd;
+ void *k;
if (unlikely(!ioc))
return NULL;
@@ -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
*/
- cic = ioc->ioc_data;
+ cic = rcu_dereference(ioc->ioc_data);
if (cic && cic->key == cfqd)
return cic;
-restart:
- n = ioc->cic_root.rb_node;
- while (n) {
- cic = rb_entry(n, struct cfq_io_context, rb_node);
+ do {
+ rcu_read_lock();
+ cic = radix_tree_lookup(&ioc->radix_root, (unsigned long) cfqd);
+ rcu_read_unlock();
+ if (!cic)
+ break;
/* ->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;
+ cfq_drop_dead_cic(cfqd, ioc, cic);
+ continue;
}
- if (key < k)
- n = n->rb_left;
- else if (key > k)
- n = n->rb_right;
- else {
- ioc->ioc_data = cic;
- return cic;
- }
- }
+ rcu_assign_pointer(ioc->ioc_data, cic);
+ break;
+ } while (1);
- return NULL;
+ return cic;
}
-static inline void
-cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc,
- struct cfq_io_context *cic)
+/*
+ * Add cic into ioc, using cfqd as the search key. This enables us to lookup
+ * 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;
- void *k;
+ int ret;
- cic->ioc = ioc;
- cic->key = cfqd;
+ ret = radix_tree_preload(gfp_mask);
+ if (!ret) {
+ cic->ioc = ioc;
+ cic->key = cfqd;
-restart:
- parent = NULL;
- p = &ioc->cic_root.rb_node;
- while (*p) {
- 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;
- }
+ spin_lock_irqsave(&ioc->lock, flags);
+ ret = radix_tree_insert(&ioc->radix_root,
+ (unsigned long) cfqd, cic);
+ spin_unlock_irqrestore(&ioc->lock, flags);
- if (cic->key < k)
- p = &(*p)->rb_left;
- else if (cic->key > k)
- p = &(*p)->rb_right;
- else
- BUG();
+ radix_tree_preload_end();
+
+ if (!ret) {
+ spin_lock_irqsave(cfqd->queue->queue_lock, flags);
+ list_add(&cic->queue_list, &cfqd->cic_list);
+ spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
+ }
}
- rb_link_node(&cic->rb_node, parent, p);
- rb_insert_color(&cic->rb_node, &ioc->cic_root);
+ if (ret)
+ printk(KERN_ERR "cfq: cic link failed!\n");
- spin_lock_irqsave(cfqd->queue->queue_lock, flags);
- list_add(&cic->queue_list, &cfqd->cic_list);
- spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
+ return ret;
}
/*
@@ -1586,7 +1591,7 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
if (!ioc)
return NULL;
- cic = cfq_cic_rb_lookup(cfqd, ioc);
+ cic = cfq_cic_lookup(cfqd, ioc);
if (cic)
goto out;
@@ -1594,13 +1599,17 @@ cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
if (cic == NULL)
goto err;
- cfq_cic_link(cfqd, ioc, cic);
+ if (cfq_cic_link(cfqd, ioc, cic, gfp_mask))
+ goto err_free;
+
out:
smp_read_barrier_depends();
if (unlikely(ioc->ioprio_changed))
cfq_ioc_set_ioprio(ioc);
return cic;
+err_free:
+ cfq_cic_free(cic);
err:
put_io_context(ioc);
return NULL;
@@ -1655,12 +1664,15 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
{
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;
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)))
enable_idle = 0;
else if (sample_valid(cic->ttime_samples)) {
@@ -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_queue *cfqq = RQ_CFQQ(rq);
- cfq_init_prio_data(cfqq);
+ cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc);
cfq_add_rq_rb(rq);
@@ -1834,7 +1846,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
cfq_set_prio_slice(cfqd, 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);
else if (sync && RB_EMPTY_ROOT(&cfqq->sort_list))
cfq_arm_slice_timer(cfqd);
@@ -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'
* if that fails
*/
- cic = cfq_cic_rb_lookup(cfqd, tsk->io_context);
+ cic = cfq_cic_lookup(cfqd, tsk->io_context);
if (!cic)
return ELV_MQUEUE_MAY;
cfqq = cic_to_cfqq(cic, rw & REQ_RW_SYNC);
if (cfqq) {
- cfq_init_prio_data(cfqq);
+ cfq_init_prio_data(cfqq, cic->ioc);
cfq_prio_boost(cfqq);
return __cfq_may_queue(cfqq);
@@ -1938,7 +1950,6 @@ static int
cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
- struct task_struct *tsk = current;
struct cfq_io_context *cic;
const int rw = rq_data_dir(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)
cfqq = cic_to_cfqq(cic, is_sync);
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)
goto queue_fail;
@@ -2039,29 +2050,9 @@ static void cfq_idle_slice_timer(unsigned long data)
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)
{
del_timer_sync(&cfqd->idle_slice_timer);
- del_timer_sync(&cfqd->idle_class_timer);
kblockd_flush_work(&cfqd->unplug_work);
}
@@ -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.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);
cfqd->last_end_request = jiffies;
@@ -2160,7 +2147,7 @@ static int __init cfq_slab_setup(void)
if (!cfq_pool)
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)
goto fail;
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 3d0422f48453c0019ad8d1de25eaa4643bb379fe..b901db63f6ae082f1df23e3227c9ddd2e56d61d1 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -3853,55 +3853,100 @@ int __init blk_dev_init(void)
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)
- return;
+ return 1;
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_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();
+ cfq_dtor(ioc);
kmem_cache_free(iocontext_cachep, ioc);
+ return 1;
}
+ return 0;
}
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 */
void exit_io_context(void)
{
struct io_context *ioc;
- struct cfq_io_context *cic;
task_lock(current);
ioc = current->io_context;
current->io_context = NULL;
task_unlock(current);
- ioc->task = NULL;
- if (ioc->aic && ioc->aic->exit)
- ioc->aic->exit(ioc->aic);
- if (ioc->cic_root.rb_node != NULL) {
- cic = rb_entry(rb_first(&ioc->cic_root), struct cfq_io_context, rb_node);
- cic->exit(ioc);
+ if (atomic_dec_and_test(&ioc->nr_tasks)) {
+ if (ioc->aic && ioc->aic->exit)
+ ioc->aic->exit(ioc->aic);
+ cfq_exit(ioc);
+
+ put_io_context(ioc);
}
+}
+
+struct io_context *alloc_io_context(gfp_t gfp_flags, int node)
+{
+ struct io_context *ret;
- put_io_context(ioc);
+ 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)
if (likely(ret))
return ret;
- ret = kmem_cache_alloc_node(iocontext_cachep, gfp_flags, node);
+ ret = alloc_io_context(gfp_flags, node);
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 */
smp_wmb();
tsk->io_context = ret;
@@ -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 *ret;
- ret = current_io_context(gfp_flags, node);
- if (likely(ret))
- atomic_inc(&ret->refcount);
+ 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);
+ if (unlikely(!ret))
+ break;
+ } while (!atomic_inc_not_zero(&ret->refcount));
+
return ret;
}
EXPORT_SYMBOL(get_io_context);
diff --git a/fs/ioprio.c b/fs/ioprio.c
index e4e01bc7f3387daf2b9282a4ec614a50b5955190..c4a1c3c65aac35ba999a4739fb3ed6549b5e1b75 100644
--- a/fs/ioprio.c
+++ b/fs/ioprio.c
@@ -41,18 +41,28 @@ static int set_task_ioprio(struct task_struct *task, int ioprio)
return err;
task_lock(task);
+ do {
+ ioc = task->io_context;
+ /* see wmb() in current_io_context() */
+ smp_read_barrier_depends();
+ if (ioc)
+ break;
- task->ioprio = ioprio;
-
- ioc = task->io_context;
- /* see wmb() in current_io_context() */
- smp_read_barrier_depends();
+ ioc = alloc_io_context(GFP_ATOMIC, -1);
+ if (!ioc) {
+ err = -ENOMEM;
+ break;
+ }
+ task->io_context = ioc;
+ } while (1);
- if (ioc)
+ if (!err) {
+ ioc->ioprio = ioprio;
ioc->ioprio_changed = 1;
+ }
task_unlock(task);
- return 0;
+ return err;
}
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;
case IOPRIO_CLASS_IDLE:
- if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
break;
case IOPRIO_CLASS_NONE:
if (data)
@@ -148,7 +156,9 @@ static int get_task_ioprio(struct task_struct *p)
ret = security_task_getioprio(p);
if (ret)
goto out;
- ret = p->ioprio;
+ ret = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, IOPRIO_NORM);
+ if (p->io_context)
+ ret = p->io_context->ioprio;
out:
return ret;
}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 49b7a4c31a6d5d35af9c3e11e24791afe86faaf4..2483a05231c73d25a8e21ec1cb2129c0f7805b7b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -34,83 +34,10 @@ struct sg_io_hdr;
#define BLKDEV_MIN_RQ 4
#define BLKDEV_MAX_RQ 128 /* Default maximum */
-/*
- * 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);
+int put_io_context(struct io_context *ioc);
void exit_io_context(void);
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 swap_io_context(struct io_context **ioc1, struct io_context **ioc2);
@@ -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
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 796019b22b6ff5c549c609530e454d37d162b1d4..e6b3f70806790b2a8e7810b3258cddc8b69cb748 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -137,7 +137,6 @@ extern struct group_info init_groups;
.time_slice = HZ, \
.nr_cpus_allowed = NR_CPUS, \
}, \
- .ioprio = 0, \
.tasks = LIST_HEAD_INIT(tsk.tasks), \
.ptrace_children= LIST_HEAD_INIT(tsk.ptrace_children), \
.ptrace_list = LIST_HEAD_INIT(tsk.ptrace_list), \
diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h
new file mode 100644
index 0000000000000000000000000000000000000000..593b222d9dcc25334be5ca6d05dc0a5ab413f5f5
--- /dev/null
+++ b/include/linux/iocontext.h
@@ -0,0 +1,95 @@
+#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
diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h
index baf29387cab4201a991ff4a8663fbba5e05fa149..2a3bb1bb74336f27c27f6627153900d46d6c178a 100644
--- a/include/linux/ioprio.h
+++ b/include/linux/ioprio.h
@@ -2,6 +2,7 @@
#define IOPRIO_H
#include <linux/sched.h>
+#include <linux/iocontext.h>
/*
* Gives us 8 prio classes with 13-bits of data for each class
@@ -45,18 +46,18 @@ enum {
* the cpu scheduler nice value to an io priority
*/
#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))
- return IOPRIO_PRIO_DATA(task->ioprio);
+ if (ioprio_valid(ioc->ioprio))
+ return IOPRIO_PRIO_DATA(ioc->ioprio);
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))
- return IOPRIO_PRIO_CLASS(task->ioprio);
+ if (ioprio_valid(ioc->ioprio))
+ return IOPRIO_PRIO_CLASS(ioc->ioprio);
return IOPRIO_CLASS_BE;
}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index df5b24ee80b307044bb5292404d1fc41686c8a6d..2d0546e884ea0fe443f88a74a01f39bbd5f86cb4 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -27,6 +27,7 @@
#define CLONE_NEWUSER 0x10000000 /* New user namespace */
#define CLONE_NEWPID 0x20000000 /* New pid namespace */
#define CLONE_NEWNET 0x40000000 /* New network namespace */
+#define CLONE_IO 0x80000000 /* Clone io context */
/*
* Scheduling policies
@@ -975,7 +976,6 @@ struct task_struct {
struct hlist_head preempt_notifiers;
#endif
- unsigned short ioprio;
/*
* fpu_counter contains the number of consecutive context switches
* that the FPU is used. If this is over a threshold, the lazy fpu
diff --git a/kernel/fork.c b/kernel/fork.c
index 39d22b3357dea001d75e37bc70e0ae8190321d2c..314f5101d2b0e5f864f22fce25c4255c7305f789 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -51,6 +51,7 @@
#include <linux/random.h>
#include <linux/tty.h>
#include <linux/proc_fs.h>
+#include <linux/blkdev.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -791,6 +792,31 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
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.
* We don't want to expose copy_files internals to
@@ -1156,15 +1182,17 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto bad_fork_cleanup_mm;
if ((retval = copy_namespaces(clone_flags, p)))
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);
if (retval)
- goto bad_fork_cleanup_namespaces;
+ goto bad_fork_cleanup_io;
if (pid != &init_struct_pid) {
retval = -ENOMEM;
pid = alloc_pid(task_active_pid_ns(p));
if (!pid)
- goto bad_fork_cleanup_namespaces;
+ goto bad_fork_cleanup_io;
if (clone_flags & CLONE_NEWPID) {
retval = pid_ns_prepare_proc(task_active_pid_ns(p));
@@ -1234,9 +1262,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
/* Need tasklist lock for parent etc handling! */
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
* not be changed, nor will its assigned CPU.
@@ -1328,6 +1353,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
bad_fork_free_pid:
if (pid != &init_struct_pid)
free_pid(pid);
+bad_fork_cleanup_io:
+ put_io_context(p->io_context);
bad_fork_cleanup_namespaces:
exit_task_namespaces(p);
bad_fork_cleanup_keys: