* Based on ideas from a previously unfinished io
* scheduler (round robin per-process disk scheduling) and Andrea Arcangeli.
*
+ * IO priorities are supported, from 0% to 100% in 5% increments. Both of
+ * those values have special meaning - 0% class is allowed to do io if
+ * noone else wants to use the disk. 100% is considered real-time io, and
+ * always get priority. Default process io rate is 95%. In absence of other
+ * io, a class may consume 100% disk bandwidth regardless. Withing a class,
+ * bandwidth is distributed equally among the citizens.
+ *
+ * TODO:
+ * - cfq_select_requests() needs some work for 5-95% io
+ * - barriers not supported
+ * - export grace periods in ms, not jiffies
+ *
* Copyright (C) 2003 Jens Axboe <axboe@suse.de>
*/
#include <linux/kernel.h>
#include <linux/rbtree.h>
#include <linux/mempool.h>
+#if IOPRIO_NR > BITS_PER_LONG
+#error Cannot support this many io priority levels
+#endif
+
/*
* tunables
*/
-static int cfq_quantum = 4;
-static int cfq_queued = 8;
+static int cfq_quantum = 6;
+static int cfq_quantum_io = 256;
+static int cfq_idle_quantum = 1;
+static int cfq_idle_quantum_io = 64;
+static int cfq_queued = 4;
+static int cfq_grace_rt = HZ / 100 ?: 1;
+static int cfq_grace_idle = HZ / 10;
#define CFQ_QHASH_SHIFT 6
#define CFQ_QHASH_ENTRIES (1 << CFQ_QHASH_SHIFT)
-#define list_entry_qhash(entry) list_entry((entry), struct cfq_queue, cfq_hash)
+#define list_entry_qhash(entry) hlist_entry((entry), struct cfq_queue, cfq_hash)
#define CFQ_MHASH_SHIFT 8
#define CFQ_MHASH_BLOCK(sec) ((sec) >> 3)
#define CFQ_MHASH_ENTRIES (1 << CFQ_MHASH_SHIFT)
#define CFQ_MHASH_FN(sec) (hash_long(CFQ_MHASH_BLOCK((sec)),CFQ_MHASH_SHIFT))
-#define ON_MHASH(crq) !list_empty(&(crq)->hash)
#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors)
-#define list_entry_hash(ptr) list_entry((ptr), struct cfq_rq, hash)
+#define list_entry_hash(ptr) hlist_entry((ptr), struct cfq_rq, hash)
#define list_entry_cfqq(ptr) list_entry((ptr), struct cfq_queue, cfq_list)
+#define list_entry_prio(ptr) list_entry((ptr), struct cfq_rq, prio_list)
+
+#define cfq_account_io(crq) \
+ ((crq)->ioprio != IOPRIO_IDLE && (crq)->ioprio != IOPRIO_RT)
-#define RQ_DATA(rq) ((struct cfq_rq *) (rq)->elevator_private)
+/*
+ * defines how we distribute bandwidth (can be tgid, uid, etc)
+ */
+
+/* FIXME: change hash_key to be sizeof(void *) rather than sizeof(int)
+ * otherwise the cast of cki_tsk_icls will not work reliably on 64-bit arches.
+ * OR, change cki_tsk_icls to return ints (will need another id space to be
+ * managed)
+ */
+
+#if defined(CONFIG_CKRM_RES_BLKIO) || defined(CONFIG_CKRM_RES_BLKIO_MODULE)
+extern inline void *cki_hash_key(struct task_struct *tsk);
+extern inline int cki_ioprio(struct task_struct *tsk);
+#define cfq_hash_key(current) ((int)cki_hash_key((current)))
+#define cfq_ioprio(current) (cki_ioprio((current)))
+
+#else
+#define cfq_hash_key(current) ((current)->tgid)
+/*
+ * move to io_context
+ */
+#define cfq_ioprio(current) ((current)->ioprio)
+#endif
+
+#define CFQ_WAIT_RT 0
+#define CFQ_WAIT_NORM 1
static kmem_cache_t *crq_pool;
static kmem_cache_t *cfq_pool;
static mempool_t *cfq_mpool;
-struct cfq_data {
+/*
+ * defines an io priority level
+ */
+struct io_prio_data {
struct list_head rr_list;
+ int busy_queues;
+ int busy_rq;
+ unsigned long busy_sectors;
+
+ /* Statistics on requests, sectors and queues
+ * added to (in) and dispatched from (out)
+ * this priority level. Reinsertion of previously
+ * dispatched crq's into cfq's results in double counting
+ * which is ignored for now as in-out should
+ * still be accurate.
+ */
+ atomic_t cum_rq_in,cum_rq_out;
+ atomic_t cum_sectors_in,cum_sectors_out;
+ atomic_t cum_queues_in,cum_queues_out;
+
+ struct list_head prio_list;
+ int last_rq;
+ int last_sectors;
+};
+
+/*
+ * per-request queue structure
+ */
+struct cfq_data {
struct list_head *dispatch;
- struct list_head *cfq_hash;
+ struct hlist_head *cfq_hash;
+ struct hlist_head *crq_hash;
+ mempool_t *crq_pool;
- struct list_head *crq_hash;
+ struct io_prio_data cid[IOPRIO_NR];
- unsigned int busy_queues;
- unsigned int max_queued;
+ /*
+ * total number of busy queues and requests
+ */
+ int busy_rq;
+ int busy_queues;
+ unsigned long busy_sectors;
- mempool_t *crq_pool;
+ unsigned long rq_starved_mask;
- request_queue_t *queue;
+ /*
+ * grace period handling
+ */
+ struct timer_list timer;
+ unsigned long wait_end;
+ unsigned long flags;
+ struct work_struct work;
/*
* tunables
*/
unsigned int cfq_quantum;
+ unsigned int cfq_quantum_io;
+ unsigned int cfq_idle_quantum;
+ unsigned int cfq_idle_quantum_io;
unsigned int cfq_queued;
+ unsigned int cfq_grace_rt;
+ unsigned int cfq_grace_idle;
};
+/*
+ * per-class structure
+ */
struct cfq_queue {
- struct list_head cfq_hash;
struct list_head cfq_list;
+ struct hlist_node cfq_hash;
+ int hash_key;
struct rb_root sort_list;
- int pid;
int queued[2];
-#if 0
- /*
- * with a simple addition like this, we can do io priorities. almost.
- * does need a split request free list, too.
- */
- int io_prio
-#endif
+ int ioprio;
};
+/*
+ * per-request structure
+ */
struct cfq_rq {
+ struct cfq_queue *cfq_queue;
struct rb_node rb_node;
+ struct hlist_node hash;
sector_t rb_key;
struct request *request;
- struct cfq_queue *cfq_queue;
-
- struct list_head hash;
+ struct list_head prio_list;
+ unsigned long nr_sectors;
+ int ioprio;
};
static void cfq_put_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq);
static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *cfqd, int pid);
-static void cfq_dispatch_sort(struct cfq_data *cfqd, struct cfq_queue *cfqq,
- struct cfq_rq *crq);
+static void cfq_dispatch_sort(struct list_head *head, struct cfq_rq *crq);
/*
* lots of deadline iosched dupes, can be abstracted later...
*/
-static inline void __cfq_del_crq_hash(struct cfq_rq *crq)
-{
- list_del_init(&crq->hash);
-}
-
static inline void cfq_del_crq_hash(struct cfq_rq *crq)
{
- if (ON_MHASH(crq))
- __cfq_del_crq_hash(crq);
+ hlist_del_init(&crq->hash);
}
-static void cfq_remove_merge_hints(request_queue_t *q, struct cfq_rq *crq)
+static inline void
+cfq_remove_merge_hints(request_queue_t *q, struct cfq_rq *crq)
{
cfq_del_crq_hash(crq);
static inline void cfq_add_crq_hash(struct cfq_data *cfqd, struct cfq_rq *crq)
{
struct request *rq = crq->request;
+ const int hash_idx = CFQ_MHASH_FN(rq_hash_key(rq));
- BUG_ON(ON_MHASH(crq));
+ BUG_ON(!hlist_unhashed(&crq->hash));
- list_add(&crq->hash, &cfqd->crq_hash[CFQ_MHASH_FN(rq_hash_key(rq))]);
+ hlist_add_head(&crq->hash, &cfqd->crq_hash[hash_idx]);
}
static struct request *cfq_find_rq_hash(struct cfq_data *cfqd, sector_t offset)
{
- struct list_head *hash_list = &cfqd->crq_hash[CFQ_MHASH_FN(offset)];
- struct list_head *entry, *next = hash_list->next;
+ struct hlist_head *hash_list = &cfqd->crq_hash[CFQ_MHASH_FN(offset)];
+ struct hlist_node *entry, *next;
- while ((entry = next) != hash_list) {
+ hlist_for_each_safe(entry, next, hash_list) {
struct cfq_rq *crq = list_entry_hash(entry);
struct request *__rq = crq->request;
- next = entry->next;
-
- BUG_ON(!ON_MHASH(crq));
+ BUG_ON(hlist_unhashed(&crq->hash));
if (!rq_mergeable(__rq)) {
- __cfq_del_crq_hash(crq);
+ cfq_del_crq_hash(crq);
continue;
}
/*
* rb tree support functions
*/
-#define RB_NONE (2)
-#define RB_EMPTY(node) ((node)->rb_node == NULL)
-#define RB_CLEAR(node) ((node)->rb_color = RB_NONE)
-#define RB_CLEAR_ROOT(root) ((root)->rb_node = NULL)
-#define ON_RB(node) ((node)->rb_color != RB_NONE)
+#define RB_EMPTY(node) ((node)->rb_node == NULL)
#define rb_entry_crq(node) rb_entry((node), struct cfq_rq, rb_node)
#define rq_rb_key(rq) (rq)->sector
-static inline void cfq_del_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
+static void
+cfq_del_crq_rb(struct cfq_data *cfqd, struct cfq_queue *cfqq,struct cfq_rq *crq)
{
- if (ON_RB(&crq->rb_node)) {
+ if (crq->cfq_queue) {
+ crq->cfq_queue = NULL;
+
+ if (cfq_account_io(crq)) {
+ cfqd->busy_rq--;
+ cfqd->busy_sectors -= crq->nr_sectors;
+ cfqd->cid[crq->ioprio].busy_rq--;
+ atomic_inc(&(cfqd->cid[crq->ioprio].cum_rq_out));
+ cfqd->cid[crq->ioprio].busy_sectors -= crq->nr_sectors;
+ atomic_add(crq->nr_sectors,&(cfqd->cid[crq->ioprio].cum_sectors_out));
+ }
+
cfqq->queued[rq_data_dir(crq->request)]--;
rb_erase(&crq->rb_node, &cfqq->sort_list);
- crq->cfq_queue = NULL;
}
}
}
rb_link_node(&crq->rb_node, parent, p);
- return NULL;
+ return 0;
}
static void
struct request *rq = crq->request;
struct cfq_rq *__alias;
- crq->rb_key = rq_rb_key(rq);
cfqq->queued[rq_data_dir(rq)]++;
+ if (cfq_account_io(crq)) {
+ cfqd->busy_rq++;
+ cfqd->busy_sectors += crq->nr_sectors;
+ cfqd->cid[crq->ioprio].busy_rq++;
+ atomic_inc(&(cfqd->cid[crq->ioprio].cum_rq_in));
+ cfqd->cid[crq->ioprio].busy_sectors += crq->nr_sectors;
+ atomic_add(crq->nr_sectors,&(cfqd->cid[crq->ioprio].cum_sectors_in));
+ }
retry:
__alias = __cfq_add_crq_rb(cfqq, crq);
if (!__alias) {
rb_insert_color(&crq->rb_node, &cfqq->sort_list);
+ crq->rb_key = rq_rb_key(rq);
crq->cfq_queue = cfqq;
return;
}
- cfq_dispatch_sort(cfqd, cfqq, __alias);
+ cfq_del_crq_rb(cfqd, cfqq, __alias);
+ cfq_dispatch_sort(cfqd->dispatch, __alias);
goto retry;
}
static struct request *
cfq_find_rq_rb(struct cfq_data *cfqd, sector_t sector)
{
- struct cfq_queue *cfqq = cfq_find_cfq_hash(cfqd, current->tgid);
+ struct cfq_queue *cfqq = cfq_find_cfq_hash(cfqd, cfq_hash_key(current));
struct rb_node *n;
if (!cfqq)
static void cfq_remove_request(request_queue_t *q, struct request *rq)
{
struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_rq *crq = RQ_DATA(rq);
+ struct cfq_rq *crq = RQ_ELV_DATA(rq);
if (crq) {
- struct cfq_queue *cfqq = crq->cfq_queue;
-
cfq_remove_merge_hints(q, crq);
+ list_del_init(&crq->prio_list);
list_del_init(&rq->queuelist);
- if (cfqq) {
- cfq_del_crq_rb(cfqq, crq);
+ /*
+ * set a grace period timer to allow realtime io to make real
+ * progress, if we release an rt request. for normal request,
+ * set timer so idle io doesn't interfere with other io
+ */
+ if (crq->ioprio == IOPRIO_RT) {
+ set_bit(CFQ_WAIT_RT, &cfqd->flags);
+ cfqd->wait_end = jiffies + cfqd->cfq_grace_rt;
+ } else if (crq->ioprio != IOPRIO_IDLE) {
+ set_bit(CFQ_WAIT_NORM, &cfqd->flags);
+ cfqd->wait_end = jiffies + cfqd->cfq_grace_idle;
+ }
+
+ if (crq->cfq_queue) {
+ struct cfq_queue *cfqq = crq->cfq_queue;
+
+ cfq_del_crq_rb(cfqd, cfqq, crq);
if (RB_EMPTY(&cfqq->sort_list))
cfq_put_queue(cfqd, cfqq);
static void cfq_merged_request(request_queue_t *q, struct request *req)
{
struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_rq *crq = RQ_DATA(req);
+ struct cfq_rq *crq = RQ_ELV_DATA(req);
cfq_del_crq_hash(crq);
cfq_add_crq_hash(cfqd, crq);
- if (ON_RB(&crq->rb_node) && (rq_rb_key(req) != crq->rb_key)) {
+ if (crq->cfq_queue && (rq_rb_key(req) != crq->rb_key)) {
struct cfq_queue *cfqq = crq->cfq_queue;
- cfq_del_crq_rb(cfqq, crq);
+ cfq_del_crq_rb(cfqd, cfqq, crq);
cfq_add_crq_rb(cfqd, cfqq, crq);
}
+ cfqd->busy_sectors += req->hard_nr_sectors - crq->nr_sectors;
+ cfqd->cid[crq->ioprio].busy_sectors += req->hard_nr_sectors - crq->nr_sectors;
+ crq->nr_sectors = req->hard_nr_sectors;
+
q->last_merge = req;
}
cfq_remove_request(q, next);
}
-static void
-cfq_dispatch_sort(struct cfq_data *cfqd, struct cfq_queue *cfqq,
- struct cfq_rq *crq)
+/*
+ * sort into dispatch list, in optimal ascending order
+ */
+static void cfq_dispatch_sort(struct list_head *head, struct cfq_rq *crq)
{
- struct list_head *head = cfqd->dispatch, *entry = head;
+ struct list_head *entry = head;
struct request *__rq;
- cfq_del_crq_rb(cfqq, crq);
- cfq_remove_merge_hints(cfqd->queue, crq);
-
if (!list_empty(head)) {
__rq = list_entry_rq(head->next);
list_add_tail(&crq->request->queuelist, entry);
}
-static inline void
+/*
+ * remove from io scheduler core and put on dispatch list for service
+ */
+static inline int
__cfq_dispatch_requests(request_queue_t *q, struct cfq_data *cfqd,
struct cfq_queue *cfqq)
{
- struct cfq_rq *crq = rb_entry_crq(rb_first(&cfqq->sort_list));
+ struct cfq_rq *crq;
- cfq_dispatch_sort(cfqd, cfqq, crq);
+ crq = rb_entry_crq(rb_first(&cfqq->sort_list));
+
+ cfq_del_crq_rb(cfqd, cfqq, crq);
+ cfq_remove_merge_hints(q, crq);
+ cfq_dispatch_sort(cfqd->dispatch, crq);
+
+ /*
+ * technically, for IOPRIO_RT we don't need to add it to the list.
+ */
+ list_add_tail(&crq->prio_list, &cfqd->cid[cfqq->ioprio].prio_list);
+ return crq->nr_sectors;
}
-static int cfq_dispatch_requests(request_queue_t *q, struct cfq_data *cfqd)
+static int
+cfq_dispatch_requests(request_queue_t *q, int prio, int max_rq, int max_sectors)
{
- struct cfq_queue *cfqq;
- struct list_head *entry, *tmp;
- int ret, queued, good_queues;
-
- if (list_empty(&cfqd->rr_list))
- return 0;
+ struct cfq_data *cfqd = q->elevator.elevator_data;
+ struct list_head *plist = &cfqd->cid[prio].rr_list;
+ struct list_head *entry, *nxt;
+ int q_rq, q_io;
- queued = ret = 0;
-restart:
- good_queues = 0;
- list_for_each_safe(entry, tmp, &cfqd->rr_list) {
- cfqq = list_entry_cfqq(cfqd->rr_list.next);
+ /*
+ * for each queue at this prio level, dispatch a request
+ */
+ q_rq = q_io = 0;
+ list_for_each_safe(entry, nxt, plist) {
+ struct cfq_queue *cfqq = list_entry_cfqq(entry);
BUG_ON(RB_EMPTY(&cfqq->sort_list));
- __cfq_dispatch_requests(q, cfqd, cfqq);
+ q_io += __cfq_dispatch_requests(q, cfqd, cfqq);
+ q_rq++;
if (RB_EMPTY(&cfqq->sort_list))
cfq_put_queue(cfqd, cfqq);
- else
- good_queues++;
- queued++;
- ret = 1;
+ /*
+ * if we hit the queue limit, put the string of serviced
+ * queues at the back of the pending list
+ */
+ if (q_io >= max_sectors || q_rq >= max_rq) {
+ struct list_head *prv = nxt->prev;
+
+ if (prv != plist) {
+ list_del(plist);
+ list_add(plist, prv);
+ }
+ break;
+ }
}
- if ((queued < cfqd->cfq_quantum) && good_queues)
- goto restart;
+ cfqd->cid[prio].last_rq = q_rq;
+ cfqd->cid[prio].last_sectors = q_io;
+ return q_rq;
+}
- return ret;
+/*
+ * try to move some requests to the dispatch list. return 0 on success
+ */
+static int cfq_select_requests(request_queue_t *q, struct cfq_data *cfqd)
+{
+ int queued, busy_rq, busy_sectors, i;
+
+ /*
+ * if there's any realtime io, only schedule that
+ */
+ if (cfq_dispatch_requests(q, IOPRIO_RT, cfqd->cfq_quantum, cfqd->cfq_quantum_io))
+ return 1;
+
+ /*
+ * if RT io was last serviced and grace time hasn't expired,
+ * arm the timer to restart queueing if no other RT io has been
+ * submitted in the mean time
+ */
+ if (test_bit(CFQ_WAIT_RT, &cfqd->flags)) {
+ if (time_before(jiffies, cfqd->wait_end)) {
+ mod_timer(&cfqd->timer, cfqd->wait_end);
+ return 0;
+ }
+ clear_bit(CFQ_WAIT_RT, &cfqd->flags);
+ }
+
+ /*
+ * for each priority level, calculate number of requests we
+ * are allowed to put into service.
+ */
+ queued = 0;
+ busy_rq = cfqd->busy_rq;
+ busy_sectors = cfqd->busy_sectors;
+ for (i = IOPRIO_RT - 1; i > IOPRIO_IDLE; i--) {
+ const int o_rq = busy_rq - cfqd->cid[i].busy_rq;
+ const int o_sectors = busy_sectors - cfqd->cid[i].busy_sectors;
+ int q_rq = cfqd->cfq_quantum * (i + 1) / IOPRIO_NR;
+ int q_io = cfqd->cfq_quantum_io * (i + 1) / IOPRIO_NR;
+
+ /*
+ * no need to keep iterating the list, if there are no
+ * requests pending anymore
+ */
+ if (!cfqd->busy_rq)
+ break;
+
+ /*
+ * find out how many requests and sectors we are allowed to
+ * service
+ */
+ if (o_rq)
+ q_rq = o_sectors * (i + 1) / IOPRIO_NR;
+ if (q_rq > cfqd->cfq_quantum)
+ q_rq = cfqd->cfq_quantum;
+
+ if (o_sectors)
+ q_io = o_sectors * (i + 1) / IOPRIO_NR;
+ if (q_io > cfqd->cfq_quantum_io)
+ q_io = cfqd->cfq_quantum_io;
+
+ /*
+ * average with last dispatched for fairness
+ */
+ if (cfqd->cid[i].last_rq != -1)
+ q_rq = (cfqd->cid[i].last_rq + q_rq) / 2;
+ if (cfqd->cid[i].last_sectors != -1)
+ q_io = (cfqd->cid[i].last_sectors + q_io) / 2;
+
+ queued += cfq_dispatch_requests(q, i, q_rq, q_io);
+ }
+
+ if (queued)
+ return 1;
+
+ /*
+ * only allow dispatch of idle io, if the queue has been idle from
+ * servicing RT or normal io for the grace period
+ */
+ if (test_bit(CFQ_WAIT_NORM, &cfqd->flags)) {
+ if (time_before(jiffies, cfqd->wait_end)) {
+ mod_timer(&cfqd->timer, cfqd->wait_end);
+ return 0;
+ }
+ clear_bit(CFQ_WAIT_NORM, &cfqd->flags);
+ }
+
+ /*
+ * if we found nothing to do, allow idle io to be serviced
+ */
+ if (cfq_dispatch_requests(q, IOPRIO_IDLE, cfqd->cfq_idle_quantum, cfqd->cfq_idle_quantum_io))
+ return 1;
+
+ return 0;
}
static struct request *cfq_next_request(request_queue_t *q)
if (!list_empty(cfqd->dispatch)) {
struct cfq_rq *crq;
dispatch:
+ /*
+ * end grace period, we are servicing a request
+ */
+ del_timer(&cfqd->timer);
+ clear_bit(CFQ_WAIT_RT, &cfqd->flags);
+ clear_bit(CFQ_WAIT_NORM, &cfqd->flags);
+
+ BUG_ON(list_empty(cfqd->dispatch));
rq = list_entry_rq(cfqd->dispatch->next);
- crq = RQ_DATA(rq);
- if (crq)
- cfq_remove_merge_hints(q, crq);
+ BUG_ON(q->last_merge == rq);
+ crq = RQ_ELV_DATA(rq);
+ if (crq) {
+ BUG_ON(!hlist_unhashed(&crq->hash));
+ list_del_init(&crq->prio_list);
+ }
return rq;
}
- if (cfq_dispatch_requests(q, cfqd))
+ /*
+ * we moved requests to dispatch list, go back end serve one
+ */
+ if (cfq_select_requests(q, cfqd))
goto dispatch;
return NULL;
}
static inline struct cfq_queue *
-__cfq_find_cfq_hash(struct cfq_data *cfqd, int pid, const int hashval)
+__cfq_find_cfq_hash(struct cfq_data *cfqd, int hashkey, const int hashval)
{
- struct list_head *hash_list = &cfqd->cfq_hash[hashval];
- struct list_head *entry;
+ struct hlist_head *hash_list = &cfqd->cfq_hash[hashval];
+ struct hlist_node *entry;
- list_for_each(entry, hash_list) {
+ hlist_for_each(entry, hash_list) {
struct cfq_queue *__cfqq = list_entry_qhash(entry);
- if (__cfqq->pid == pid)
+ if (__cfqq->hash_key == hashkey)
return __cfqq;
}
return NULL;
}
-static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *cfqd, int pid)
+static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *cfqd, int hashkey)
{
- const int hashval = hash_long(current->tgid, CFQ_QHASH_SHIFT);
+ const int hashval = hash_long(hashkey, CFQ_QHASH_SHIFT);
- return __cfq_find_cfq_hash(cfqd, pid, hashval);
+ return __cfq_find_cfq_hash(cfqd, hashkey, hashval);
}
static void cfq_put_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
cfqd->busy_queues--;
+ WARN_ON(cfqd->busy_queues < 0);
+
+ cfqd->cid[cfqq->ioprio].busy_queues--;
+ WARN_ON(cfqd->cid[cfqq->ioprio].busy_queues < 0);
+ atomic_inc(&(cfqd->cid[cfqq->ioprio].cum_queues_out));
+
list_del(&cfqq->cfq_list);
- list_del(&cfqq->cfq_hash);
+ hlist_del(&cfqq->cfq_hash);
mempool_free(cfqq, cfq_mpool);
}
-static struct cfq_queue *__cfq_get_queue(struct cfq_data *cfqd, int pid,
- int gfp_mask)
+static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, int hashkey)
{
- const int hashval = hash_long(current->tgid, CFQ_QHASH_SHIFT);
+ const int hashval = hash_long(hashkey, CFQ_QHASH_SHIFT);
struct cfq_queue *cfqq, *new_cfqq = NULL;
- request_queue_t *q = cfqd->queue;
-retry:
- cfqq = __cfq_find_cfq_hash(cfqd, pid, hashval);
+ retry:
+ cfqq = __cfq_find_cfq_hash(cfqd, hashkey, hashval);
if (!cfqq) {
- if (new_cfqq) {
- cfqq = new_cfqq;
- new_cfqq = NULL;
- } else if (gfp_mask & __GFP_WAIT) {
- spin_unlock_irq(q->queue_lock);
- new_cfqq = mempool_alloc(cfq_mpool, gfp_mask);
- spin_lock_irq(q->queue_lock);
- goto retry;
- } else
- return NULL;
-
- INIT_LIST_HEAD(&cfqq->cfq_hash);
+ if (new_cfqq) {
+ cfqq = new_cfqq;
+ new_cfqq = NULL;
+ } else {
+ new_cfqq = mempool_alloc(cfq_mpool, GFP_ATOMIC);
+ /* MEF: I think cfq-iosched.c needs further fixing
+ to avoid the bugon. Shailabh will be sending
+ a new patch for this soon.
+ */
+ BUG_ON(new_cfqq == NULL);
+ goto retry;
+ }
+
+ memset(cfqq, 0, sizeof(*cfqq));
+ INIT_HLIST_NODE(&cfqq->cfq_hash);
INIT_LIST_HEAD(&cfqq->cfq_list);
- RB_CLEAR_ROOT(&cfqq->sort_list);
- cfqq->pid = pid;
- cfqq->queued[0] = cfqq->queued[1] = 0;
- list_add(&cfqq->cfq_hash, &cfqd->cfq_hash[hashval]);
+ cfqq->hash_key = cfq_hash_key(current);
+ cfqq->ioprio = cfq_ioprio(current);
+ hlist_add_head(&cfqq->cfq_hash, &cfqd->cfq_hash[hashval]);
}
- if (new_cfqq)
- mempool_free(new_cfqq, cfq_mpool);
+ if (new_cfqq) {
+ mempool_free(new_cfqq, cfq_mpool);
+ }
return cfqq;
}
-static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, int pid,
- int gfp_mask)
+static void
+__cfq_enqueue(request_queue_t *q, struct cfq_data *cfqd, struct cfq_rq *crq)
{
- request_queue_t *q = cfqd->queue;
+ const int prio = crq->ioprio;
struct cfq_queue *cfqq;
- spin_lock_irq(q->queue_lock);
- cfqq = __cfq_get_queue(cfqd, pid, gfp_mask);
- spin_unlock_irq(q->queue_lock);
+ cfqq = cfq_get_queue(cfqd, cfq_hash_key(current));
+
+ /*
+ * not too good...
+ */
+ if (prio > cfqq->ioprio) {
+ printk("prio hash collision %d %d\n", prio, cfqq->ioprio);
+ if (!list_empty(&cfqq->cfq_list)) {
+ cfqd->cid[cfqq->ioprio].busy_queues--;
+ WARN_ON(cfqd->cid[cfqq->ioprio].busy_queues < 0);
+ atomic_inc(&(cfqd->cid[cfqq->ioprio].cum_queues_out));
+ cfqd->cid[prio].busy_queues++;
+ atomic_inc(&(cfqd->cid[prio].cum_queues_in));
+ list_move_tail(&cfqq->cfq_list, &cfqd->cid[prio].rr_list);
+ }
+ cfqq->ioprio = prio;
+ }
+
+ cfq_add_crq_rb(cfqd, cfqq, crq);
+
+ if (list_empty(&cfqq->cfq_list)) {
+ list_add_tail(&cfqq->cfq_list, &cfqd->cid[prio].rr_list);
+ cfqd->cid[prio].busy_queues++;
+ atomic_inc(&(cfqd->cid[prio].cum_queues_in));
+ cfqd->busy_queues++;
+ }
+
+ if (rq_mergeable(crq->request)) {
+ cfq_add_crq_hash(cfqd, crq);
+
+ if (!q->last_merge)
+ q->last_merge = crq->request;
+ }
- return cfqq;
}
-static void cfq_enqueue(struct cfq_data *cfqd, struct cfq_rq *crq)
+static void cfq_reenqueue(request_queue_t *q, struct cfq_data *cfqd, int prio)
{
- struct cfq_queue *cfqq;
+ struct list_head *prio_list = &cfqd->cid[prio].prio_list;
+ struct list_head *entry, *tmp;
- cfqq = __cfq_get_queue(cfqd, current->tgid, GFP_ATOMIC);
- if (cfqq) {
- cfq_add_crq_rb(cfqd, cfqq, crq);
+ list_for_each_safe(entry, tmp, prio_list) {
+ struct cfq_rq *crq = list_entry_prio(entry);
- if (list_empty(&cfqq->cfq_list)) {
- list_add(&cfqq->cfq_list, &cfqd->rr_list);
- cfqd->busy_queues++;
- }
- } else {
+ list_del_init(entry);
+ list_del_init(&crq->request->queuelist);
+ __cfq_enqueue(q, cfqd, crq);
+ }
+}
+
+static void
+cfq_enqueue(request_queue_t *q, struct cfq_data *cfqd, struct cfq_rq *crq)
+{
+ const int prio = cfq_ioprio(current);
+
+ crq->ioprio = prio;
+ crq->nr_sectors = crq->request->hard_nr_sectors;
+ __cfq_enqueue(q, cfqd, crq);
+
+ if (prio == IOPRIO_RT) {
+ int i;
+
+ /*
+ * realtime io gets priority, move all other io back
+ */
+ for (i = IOPRIO_IDLE; i < IOPRIO_RT; i++)
+ cfq_reenqueue(q, cfqd, i);
+ } else if (prio != IOPRIO_IDLE) {
/*
- * should can only happen if the request wasn't allocated
- * through blk_alloc_request(), eg stack requests from ide-cd
- * (those should be removed) _and_ we are in OOM.
+ * check if we need to move idle io back into queue
*/
- list_add_tail(&crq->request->queuelist, cfqd->dispatch);
+ cfq_reenqueue(q, cfqd, IOPRIO_IDLE);
}
}
cfq_insert_request(request_queue_t *q, struct request *rq, int where)
{
struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_rq *crq = RQ_DATA(rq);
+ struct cfq_rq *crq = RQ_ELV_DATA(rq);
switch (where) {
case ELEVATOR_INSERT_BACK:
+#if 0
while (cfq_dispatch_requests(q, cfqd))
;
+#endif
list_add_tail(&rq->queuelist, cfqd->dispatch);
break;
case ELEVATOR_INSERT_FRONT:
break;
case ELEVATOR_INSERT_SORT:
BUG_ON(!blk_fs_request(rq));
- cfq_enqueue(cfqd, crq);
+ cfq_enqueue(q, cfqd, crq);
break;
default:
printk("%s: bad insert point %d\n", __FUNCTION__,where);
return;
}
-
- if (rq_mergeable(rq)) {
- cfq_add_crq_hash(cfqd, crq);
-
- if (!q->last_merge)
- q->last_merge = rq;
- }
}
static int cfq_queue_empty(request_queue_t *q)
{
struct cfq_data *cfqd = q->elevator.elevator_data;
- if (list_empty(cfqd->dispatch) && list_empty(&cfqd->rr_list))
+ if (list_empty(cfqd->dispatch) && !cfqd->busy_queues)
return 1;
return 0;
static struct request *
cfq_former_request(request_queue_t *q, struct request *rq)
{
- struct cfq_rq *crq = RQ_DATA(rq);
+ struct cfq_rq *crq = RQ_ELV_DATA(rq);
struct rb_node *rbprev = rb_prev(&crq->rb_node);
if (rbprev)
static struct request *
cfq_latter_request(request_queue_t *q, struct request *rq)
{
- struct cfq_rq *crq = RQ_DATA(rq);
+ struct cfq_rq *crq = RQ_ELV_DATA(rq);
struct rb_node *rbnext = rb_next(&crq->rb_node);
if (rbnext)
return NULL;
}
+static void cfq_queue_congested(request_queue_t *q)
+{
+ struct cfq_data *cfqd = q->elevator.elevator_data;
+
+ set_bit(cfq_ioprio(current), &cfqd->rq_starved_mask);
+}
+
static int cfq_may_queue(request_queue_t *q, int rw)
{
struct cfq_data *cfqd = q->elevator.elevator_data;
struct cfq_queue *cfqq;
- int ret = 1;
+ const int prio = cfq_ioprio(current);
+ int limit, ret = 1;
if (!cfqd->busy_queues)
goto out;
- cfqq = cfq_find_cfq_hash(cfqd, current->tgid);
- if (cfqq) {
- int limit = (q->nr_requests - cfqd->cfq_queued) / cfqd->busy_queues;
+ cfqq = cfq_find_cfq_hash(cfqd, cfq_hash_key(current));
+ if (!cfqq)
+ goto out;
- if (limit < 3)
- limit = 3;
- else if (limit > cfqd->max_queued)
- limit = cfqd->max_queued;
+ cfqq = cfq_find_cfq_hash(cfqd, cfq_hash_key(current));
+ if (!cfqq)
+ goto out;
+
+ /*
+ * if higher or equal prio io is sleeping waiting for a request, don't
+ * allow this one to allocate one. as long as ll_rw_blk does fifo
+ * waitqueue wakeups this should work...
+ */
+ if (cfqd->rq_starved_mask & ~((1 << prio) - 1))
+ goto out;
+
+ if (cfqq->queued[rw] < cfqd->cfq_queued || !cfqd->cid[prio].busy_queues)
+ goto out;
+
+ limit = q->nr_requests * (prio + 1) / IOPRIO_NR;
+ limit /= cfqd->cid[prio].busy_queues;
+ if (cfqq->queued[rw] > limit)
+ ret = 0;
- if (cfqq->queued[rw] > limit)
- ret = 0;
- }
out:
return ret;
}
static void cfq_put_request(request_queue_t *q, struct request *rq)
{
struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_rq *crq = RQ_DATA(rq);
- struct request_list *rl;
- int other_rw;
+ struct cfq_rq *crq = RQ_ELV_DATA(rq);
if (crq) {
BUG_ON(q->last_merge == rq);
- BUG_ON(ON_MHASH(crq));
+ BUG_ON(!hlist_unhashed(&crq->hash));
mempool_free(crq, cfqd->crq_pool);
rq->elevator_private = NULL;
}
-
- /*
- * work-around for may_queue "bug": if a read gets issued and refused
- * to queue because writes ate all the allowed slots and no other
- * reads are pending for this queue, it could get stuck infinitely
- * since freed_request() only checks the waitqueue for writes when
- * freeing them. or vice versa for a single write vs many reads.
- * so check here whether "the other" data direction might be able
- * to queue and wake them
- */
- rl = &q->rq;
- other_rw = rq_data_dir(rq) ^ 1;
- if (rl->count[other_rw] <= q->nr_requests) {
- smp_mb();
- if (waitqueue_active(&rl->wait[other_rw]))
- wake_up(&rl->wait[other_rw]);
- }
}
static int cfq_set_request(request_queue_t *q, struct request *rq, int gfp_mask)
{
struct cfq_data *cfqd = q->elevator.elevator_data;
- struct cfq_queue *cfqq;
- struct cfq_rq *crq;
+ struct cfq_rq *crq = mempool_alloc(cfqd->crq_pool, gfp_mask);
- /*
- * prepare a queue up front, so cfq_enqueue() doesn't have to
- */
- cfqq = cfq_get_queue(cfqd, current->tgid, gfp_mask);
- if (!cfqq)
- return 1;
-
- crq = mempool_alloc(cfqd->crq_pool, gfp_mask);
if (crq) {
+ /*
+ * process now has one request
+ */
+ clear_bit(cfq_ioprio(current), &cfqd->rq_starved_mask);
+
memset(crq, 0, sizeof(*crq));
- RB_CLEAR(&crq->rb_node);
crq->request = rq;
- crq->cfq_queue = NULL;
- INIT_LIST_HEAD(&crq->hash);
+ INIT_HLIST_NODE(&crq->hash);
+ INIT_LIST_HEAD(&crq->prio_list);
rq->elevator_private = crq;
return 0;
}
kfree(cfqd);
}
+static void cfq_timer(unsigned long data)
+{
+ struct cfq_data *cfqd = (struct cfq_data *) data;
+
+ clear_bit(CFQ_WAIT_RT, &cfqd->flags);
+ clear_bit(CFQ_WAIT_NORM, &cfqd->flags);
+ kblockd_schedule_work(&cfqd->work);
+}
+
+static void cfq_work(void *data)
+{
+ request_queue_t *q = data;
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ if (cfq_next_request(q))
+ q->request_fn(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+}
+
static int cfq_init(request_queue_t *q, elevator_t *e)
{
struct cfq_data *cfqd;
return -ENOMEM;
memset(cfqd, 0, sizeof(*cfqd));
- INIT_LIST_HEAD(&cfqd->rr_list);
- cfqd->crq_hash = kmalloc(sizeof(struct list_head) * CFQ_MHASH_ENTRIES, GFP_KERNEL);
+ init_timer(&cfqd->timer);
+ cfqd->timer.function = cfq_timer;
+ cfqd->timer.data = (unsigned long) cfqd;
+
+ INIT_WORK(&cfqd->work, cfq_work, q);
+
+ for (i = 0; i < IOPRIO_NR; i++) {
+ struct io_prio_data *cid = &cfqd->cid[i];
+
+ INIT_LIST_HEAD(&cid->rr_list);
+ INIT_LIST_HEAD(&cid->prio_list);
+ cid->last_rq = -1;
+ cid->last_sectors = -1;
+
+ atomic_set(&cid->cum_rq_in,0);
+ atomic_set(&cid->cum_rq_out,0);
+ atomic_set(&cid->cum_sectors_in,0);
+ atomic_set(&cid->cum_sectors_out,0);
+ atomic_set(&cid->cum_queues_in,0);
+ atomic_set(&cid->cum_queues_out,0);
+ }
+
+ cfqd->crq_hash = kmalloc(sizeof(struct hlist_head) * CFQ_MHASH_ENTRIES, GFP_KERNEL);
if (!cfqd->crq_hash)
goto out_crqhash;
- cfqd->cfq_hash = kmalloc(sizeof(struct list_head) * CFQ_QHASH_ENTRIES, GFP_KERNEL);
+ cfqd->cfq_hash = kmalloc(sizeof(struct hlist_head) * CFQ_QHASH_ENTRIES, GFP_KERNEL);
if (!cfqd->cfq_hash)
goto out_cfqhash;
goto out_crqpool;
for (i = 0; i < CFQ_MHASH_ENTRIES; i++)
- INIT_LIST_HEAD(&cfqd->crq_hash[i]);
+ INIT_HLIST_HEAD(&cfqd->crq_hash[i]);
for (i = 0; i < CFQ_QHASH_ENTRIES; i++)
- INIT_LIST_HEAD(&cfqd->cfq_hash[i]);
-
- cfqd->dispatch = &q->queue_head;
- e->elevator_data = cfqd;
- cfqd->queue = q;
-
- /*
- * just set it to some high value, we want anyone to be able to queue
- * some requests. fairness is handled differently
- */
- cfqd->max_queued = q->nr_requests;
- q->nr_requests = 8192;
+ INIT_HLIST_HEAD(&cfqd->cfq_hash[i]);
cfqd->cfq_queued = cfq_queued;
cfqd->cfq_quantum = cfq_quantum;
+ cfqd->cfq_quantum_io = cfq_quantum_io;
+ cfqd->cfq_idle_quantum = cfq_idle_quantum;
+ cfqd->cfq_idle_quantum_io = cfq_idle_quantum_io;
+ cfqd->cfq_grace_rt = cfq_grace_rt;
+ cfqd->cfq_grace_idle = cfq_grace_idle;
+
+ q->nr_requests <<= 2;
+
+ cfqd->dispatch = &q->queue_head;
+ e->elevator_data = cfqd;
return 0;
out_crqpool:
return cfq_var_show(__VAR, (page)); \
}
SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum);
+SHOW_FUNCTION(cfq_quantum_io_show, cfqd->cfq_quantum_io);
+SHOW_FUNCTION(cfq_idle_quantum_show, cfqd->cfq_idle_quantum);
+SHOW_FUNCTION(cfq_idle_quantum_io_show, cfqd->cfq_idle_quantum_io);
SHOW_FUNCTION(cfq_queued_show, cfqd->cfq_queued);
+SHOW_FUNCTION(cfq_grace_rt_show, cfqd->cfq_grace_rt);
+SHOW_FUNCTION(cfq_grace_idle_show, cfqd->cfq_grace_idle);
#undef SHOW_FUNCTION
#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \
return ret; \
}
STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, INT_MAX);
+STORE_FUNCTION(cfq_quantum_io_store, &cfqd->cfq_quantum_io, 4, INT_MAX);
+STORE_FUNCTION(cfq_idle_quantum_store, &cfqd->cfq_idle_quantum, 1, INT_MAX);
+STORE_FUNCTION(cfq_idle_quantum_io_store, &cfqd->cfq_idle_quantum_io, 4, INT_MAX);
STORE_FUNCTION(cfq_queued_store, &cfqd->cfq_queued, 1, INT_MAX);
+STORE_FUNCTION(cfq_grace_rt_store, &cfqd->cfq_grace_rt, 0, INT_MAX);
+STORE_FUNCTION(cfq_grace_idle_store, &cfqd->cfq_grace_idle, 0, INT_MAX);
#undef STORE_FUNCTION
+
+/* Additional entries to get priority level data */
+static ssize_t
+cfq_prio_show(struct cfq_data *cfqd, char *page, unsigned int priolvl)
+{
+ int r1,r2,s1,s2,q1,q2;
+
+ if (!(priolvl >= IOPRIO_IDLE && priolvl <= IOPRIO_RT))
+ return 0;
+
+ r1 = (int)atomic_read(&(cfqd->cid[priolvl].cum_rq_in));
+ r2 = (int)atomic_read(&(cfqd->cid[priolvl].cum_rq_out));
+ s1 = (int)atomic_read(&(cfqd->cid[priolvl].cum_sectors_in));
+ s2 = (int)atomic_read(&(cfqd->cid[priolvl].cum_sectors_out));
+ q1 = (int)atomic_read(&(cfqd->cid[priolvl].cum_queues_in));
+ q2 = (int)atomic_read(&(cfqd->cid[priolvl].cum_queues_out));
+
+
+ /*
+ return sprintf(page,"rq %d (%d,%d) sec %d (%d,%d) q %d (%d,%d)\n",
+ r1-r2,r1,r2,
+ s1-s2,s1,s2,
+ q1-q2,q1,q2);
+ */
+
+ return sprintf(page,"rq (%d,%d) sec (%d,%d) q (%d,%d)\n",
+ r1,r2,
+ s1,s2,
+ q1,q2);
+
+}
+
+#define SHOW_PRIO_DATA(__PRIOLVL) \
+static ssize_t cfq_prio_##__PRIOLVL##_show(struct cfq_data *cfqd, char *page) \
+{ \
+ return cfq_prio_show(cfqd,page,__PRIOLVL); \
+}
+SHOW_PRIO_DATA(0);
+SHOW_PRIO_DATA(1);
+SHOW_PRIO_DATA(2);
+SHOW_PRIO_DATA(3);
+SHOW_PRIO_DATA(4);
+SHOW_PRIO_DATA(5);
+SHOW_PRIO_DATA(6);
+SHOW_PRIO_DATA(7);
+SHOW_PRIO_DATA(8);
+SHOW_PRIO_DATA(9);
+SHOW_PRIO_DATA(10);
+SHOW_PRIO_DATA(11);
+SHOW_PRIO_DATA(12);
+SHOW_PRIO_DATA(13);
+SHOW_PRIO_DATA(14);
+SHOW_PRIO_DATA(15);
+SHOW_PRIO_DATA(16);
+SHOW_PRIO_DATA(17);
+SHOW_PRIO_DATA(18);
+SHOW_PRIO_DATA(19);
+SHOW_PRIO_DATA(20);
+#undef SHOW_PRIO_DATA
+
+
+static ssize_t cfq_prio_store(struct cfq_data *cfqd, const char *page, size_t count, int priolvl)
+{
+ atomic_set(&(cfqd->cid[priolvl].cum_rq_in),0);
+ atomic_set(&(cfqd->cid[priolvl].cum_rq_out),0);
+ atomic_set(&(cfqd->cid[priolvl].cum_sectors_in),0);
+ atomic_set(&(cfqd->cid[priolvl].cum_sectors_out),0);
+ atomic_set(&(cfqd->cid[priolvl].cum_queues_in),0);
+ atomic_set(&(cfqd->cid[priolvl].cum_queues_out),0);
+
+ return count;
+}
+
+
+#define STORE_PRIO_DATA(__PRIOLVL) \
+static ssize_t cfq_prio_##__PRIOLVL##_store(struct cfq_data *cfqd, const char *page, size_t count) \
+{ \
+ return cfq_prio_store(cfqd,page,count,__PRIOLVL); \
+}
+STORE_PRIO_DATA(0);
+STORE_PRIO_DATA(1);
+STORE_PRIO_DATA(2);
+STORE_PRIO_DATA(3);
+STORE_PRIO_DATA(4);
+STORE_PRIO_DATA(5);
+STORE_PRIO_DATA(6);
+STORE_PRIO_DATA(7);
+STORE_PRIO_DATA(8);
+STORE_PRIO_DATA(9);
+STORE_PRIO_DATA(10);
+STORE_PRIO_DATA(11);
+STORE_PRIO_DATA(12);
+STORE_PRIO_DATA(13);
+STORE_PRIO_DATA(14);
+STORE_PRIO_DATA(15);
+STORE_PRIO_DATA(16);
+STORE_PRIO_DATA(17);
+STORE_PRIO_DATA(18);
+STORE_PRIO_DATA(19);
+STORE_PRIO_DATA(20);
+#undef STORE_PRIO_DATA
+
+
+
static struct cfq_fs_entry cfq_quantum_entry = {
.attr = {.name = "quantum", .mode = S_IRUGO | S_IWUSR },
.show = cfq_quantum_show,
.store = cfq_quantum_store,
};
+static struct cfq_fs_entry cfq_quantum_io_entry = {
+ .attr = {.name = "quantum_io", .mode = S_IRUGO | S_IWUSR },
+ .show = cfq_quantum_io_show,
+ .store = cfq_quantum_io_store,
+};
+static struct cfq_fs_entry cfq_idle_quantum_entry = {
+ .attr = {.name = "idle_quantum", .mode = S_IRUGO | S_IWUSR },
+ .show = cfq_idle_quantum_show,
+ .store = cfq_idle_quantum_store,
+};
+static struct cfq_fs_entry cfq_idle_quantum_io_entry = {
+ .attr = {.name = "idle_quantum_io", .mode = S_IRUGO | S_IWUSR },
+ .show = cfq_idle_quantum_io_show,
+ .store = cfq_idle_quantum_io_store,
+};
static struct cfq_fs_entry cfq_queued_entry = {
.attr = {.name = "queued", .mode = S_IRUGO | S_IWUSR },
.show = cfq_queued_show,
.store = cfq_queued_store,
};
+static struct cfq_fs_entry cfq_grace_rt_entry = {
+ .attr = {.name = "grace_rt", .mode = S_IRUGO | S_IWUSR },
+ .show = cfq_grace_rt_show,
+ .store = cfq_grace_rt_store,
+};
+static struct cfq_fs_entry cfq_grace_idle_entry = {
+ .attr = {.name = "grace_idle", .mode = S_IRUGO | S_IWUSR },
+ .show = cfq_grace_idle_show,
+ .store = cfq_grace_idle_store,
+};
+
+#define P_0_STR "p0"
+#define P_1_STR "p1"
+#define P_2_STR "p2"
+#define P_3_STR "p3"
+#define P_4_STR "p4"
+#define P_5_STR "p5"
+#define P_6_STR "p6"
+#define P_7_STR "p7"
+#define P_8_STR "p8"
+#define P_9_STR "p9"
+#define P_10_STR "p10"
+#define P_11_STR "p11"
+#define P_12_STR "p12"
+#define P_13_STR "p13"
+#define P_14_STR "p14"
+#define P_15_STR "p15"
+#define P_16_STR "p16"
+#define P_17_STR "p17"
+#define P_18_STR "p18"
+#define P_19_STR "p19"
+#define P_20_STR "p20"
+
+
+#define CFQ_PRIO_SYSFS_ENTRY(__PRIOLVL) \
+static struct cfq_fs_entry cfq_prio_##__PRIOLVL##_entry = { \
+ .attr = {.name = P_##__PRIOLVL##_STR, .mode = S_IRUGO | S_IWUSR }, \
+ .show = cfq_prio_##__PRIOLVL##_show, \
+ .store = cfq_prio_##__PRIOLVL##_store, \
+};
+CFQ_PRIO_SYSFS_ENTRY(0);
+CFQ_PRIO_SYSFS_ENTRY(1);
+CFQ_PRIO_SYSFS_ENTRY(2);
+CFQ_PRIO_SYSFS_ENTRY(3);
+CFQ_PRIO_SYSFS_ENTRY(4);
+CFQ_PRIO_SYSFS_ENTRY(5);
+CFQ_PRIO_SYSFS_ENTRY(6);
+CFQ_PRIO_SYSFS_ENTRY(7);
+CFQ_PRIO_SYSFS_ENTRY(8);
+CFQ_PRIO_SYSFS_ENTRY(9);
+CFQ_PRIO_SYSFS_ENTRY(10);
+CFQ_PRIO_SYSFS_ENTRY(11);
+CFQ_PRIO_SYSFS_ENTRY(12);
+CFQ_PRIO_SYSFS_ENTRY(13);
+CFQ_PRIO_SYSFS_ENTRY(14);
+CFQ_PRIO_SYSFS_ENTRY(15);
+CFQ_PRIO_SYSFS_ENTRY(16);
+CFQ_PRIO_SYSFS_ENTRY(17);
+CFQ_PRIO_SYSFS_ENTRY(18);
+CFQ_PRIO_SYSFS_ENTRY(19);
+CFQ_PRIO_SYSFS_ENTRY(20);
+#undef CFQ_PRIO_SYSFS_ENTRY
+
static struct attribute *default_attrs[] = {
&cfq_quantum_entry.attr,
+ &cfq_quantum_io_entry.attr,
+ &cfq_idle_quantum_entry.attr,
+ &cfq_idle_quantum_io_entry.attr,
&cfq_queued_entry.attr,
+ &cfq_grace_rt_entry.attr,
+ &cfq_grace_idle_entry.attr,
+ &cfq_prio_0_entry.attr,
+ &cfq_prio_1_entry.attr,
+ &cfq_prio_2_entry.attr,
+ &cfq_prio_3_entry.attr,
+ &cfq_prio_4_entry.attr,
+ &cfq_prio_5_entry.attr,
+ &cfq_prio_6_entry.attr,
+ &cfq_prio_7_entry.attr,
+ &cfq_prio_8_entry.attr,
+ &cfq_prio_9_entry.attr,
+ &cfq_prio_10_entry.attr,
+ &cfq_prio_11_entry.attr,
+ &cfq_prio_12_entry.attr,
+ &cfq_prio_13_entry.attr,
+ &cfq_prio_14_entry.attr,
+ &cfq_prio_15_entry.attr,
+ &cfq_prio_16_entry.attr,
+ &cfq_prio_17_entry.attr,
+ &cfq_prio_18_entry.attr,
+ &cfq_prio_19_entry.attr,
+ &cfq_prio_20_entry.attr,
NULL,
};
.elevator_set_req_fn = cfq_set_request,
.elevator_put_req_fn = cfq_put_request,
.elevator_may_queue_fn = cfq_may_queue,
+ .elevator_set_congested_fn = cfq_queue_congested,
.elevator_init_fn = cfq_init,
.elevator_exit_fn = cfq_exit,
};
/* Absolute shares of this class
* in local units.
*/
-
- int ioprio;
- int unused;
-
+
+ int cnt_guarantee; /* Allocation as parent */
+ int cnt_unused; /* Allocation to default subclass */
+
/* Statistics, for class and default subclass */
cki_stats_t stats;
cki_stats_t mystats;
static inline void cki_reset_stats(cki_stats_t *usg);
static inline void init_icls_one(cki_icls_t *icls);
static inline int cki_div(int *a, int b, int c);
-static inline int cki_recalc(cki_icls_t *icls, int rel2abs);
-
-#ifdef DOES_NOT_WORK_AND_NOT_NEEDED
-/* External functions e.g. interface to ioscheduler */
-inline void *cki_tsk_icls(struct task_struct *tsk);
-inline int cki_tsk_ioprio(struct task_struct *tsk);
-#endif
+//static inline int cki_recalc(cki_icls_t *icls, int rel2abs);
+static void cki_recalc_propagate(cki_icls_t *res, cki_icls_t *parres);
extern void cki_cfq_set(icls_tsk_t tskicls, icls_ioprio_t tskioprio);
static inline void init_icls_one(cki_icls_t *icls)
{
- icls->shares.my_guarantee =
- (CKI_IOPRIO_MIN * CKRM_SHARE_DFLT_TOTAL_GUARANTEE) /
- CKI_IOPRIO_DIV ;
+ // Assign zero as initial guarantee otherwise creations
+ // could fail due to inadequate share
+
+ //icls->shares.my_guarantee =
+ // (CKI_IOPRIO_MIN * CKRM_SHARE_DFLT_TOTAL_GUARANTEE) /
+ // CKI_IOPRIO_DIV ;
+ icls->shares.my_guarantee = 0;
icls->shares.my_limit = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
icls->shares.total_guarantee = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
icls->shares.max_limit = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
icls->shares.cur_max_limit = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
- icls->ioprio = CKI_IOPRIO_MIN;
- icls->unused = 0 ;
+ icls->cnt_guarantee = icls->cnt_unused = IOPRIO_IDLE;
+
+ //Same rationale icls->ioprio = CKI_IOPRIO_MIN;
+ //IOPRIO_IDLE equivalence to zero my_guarantee (set above) relies
+ //on former being zero.
init_icls_stats(icls);
}
* Caller should have a lock on icls
*/
+static void cki_recalc_propagate(cki_icls_t *res, cki_icls_t *parres)
+{
+
+ ckrm_core_class_t *child = NULL;
+ cki_icls_t *childres;
+ int resid = cki_rcbs.resid;
+
+ if (parres) {
+ struct ckrm_shares *par = &parres->shares;
+ struct ckrm_shares *self = &res->shares;
+
+
+
+ if (parres->cnt_guarantee == CKRM_SHARE_DONTCARE) {
+ res->cnt_guarantee = CKRM_SHARE_DONTCARE;
+ } else if (par->total_guarantee) {
+ u64 temp = (u64) self->my_guarantee *
+ parres->cnt_guarantee;
+ do_div(temp, par->total_guarantee);
+ res->cnt_guarantee = (int) temp;
+ } else {
+ res->cnt_guarantee = 0;
+ }
+
+ if (res->cnt_guarantee == CKRM_SHARE_DONTCARE) {
+ res->cnt_unused = CKRM_SHARE_DONTCARE;
+ } else if (self->total_guarantee) {
+ u64 temp = (u64) self->unused_guarantee *
+ res->cnt_guarantee;
+ do_div(temp, self->total_guarantee);
+ res->cnt_unused = (int) temp;
+ } else {
+ res->cnt_unused = 0;
+ }
+ }
+ // propagate to children
+ ckrm_lock_hier(res->core);
+ while ((child = ckrm_get_next_child(res->core,child)) != NULL){
+ childres = ckrm_get_res_class(child, resid,
+ cki_icls_t);
+
+ spin_lock(&childres->shares_lock);
+ cki_recalc_propagate(childres, res);
+ spin_unlock(&childres->shares_lock);
+ }
+ ckrm_unlock_hier(res->core);
+}
+
+#if 0
static inline int cki_recalc(cki_icls_t *icls, int rel2abs)
{
u64 temp;
temp = icls->shares.my_guarantee * (IOPRIO_NR-1);
do_div(temp, icls->shares.total_guarantee);
+ icls->total = IOPRIO_NR-1;
icls->ioprio = temp ;
- icls->unused = (IOPRIO_NR-1)-icls->ioprio;
+ icls->unused = icls->total - icls->ioprio;
+// icls->unused = (IOPRIO_NR-1)-icls->ioprio;
} else {
cki_icls_t *parres;
return -EINVAL;
}
- partot = parres->ioprio + parres->unused;
- temp = (icls->shares.my_guarantee * (parres->ioprio + parres->unused));
+ temp = (icls->shares.my_guarantee *
+ parres->total);
do_div(temp, parres->shares.total_guarantee);
icls->ioprio = temp;
return 0;
}
+#endif
-
-inline void *cki_icls_tsk(struct task_struct *tsk)
+void *cki_tsk_icls(struct task_struct *tsk)
{
return (void *) ckrm_get_res_class(class_core(tsk->taskclass),
cki_rcbs.resid, cki_icls_t);
}
-inline int cki_icls_ioprio(struct task_struct *tsk)
+int cki_tsk_ioprio(struct task_struct *tsk)
{
cki_icls_t *icls = ckrm_get_res_class(class_core(tsk->taskclass),
cki_rcbs.resid, cki_icls_t);
- return icls->ioprio;
+ return icls->cnt_unused;
}
static void *cki_alloc(struct ckrm_core_class *core,
icls->shares_lock = SPIN_LOCK_UNLOCKED;
if (parent == NULL) {
- u64 temp;
/* Root class gets same as "normal" CFQ priorities to
* retain compatibility of behaviour in the absence of
* other classes
*/
- icls->ioprio = IOPRIO_NORM;
- icls->unused = (IOPRIO_NR-1)-IOPRIO_NORM;
+ icls->cnt_guarantee = icls->cnt_unused = IOPRIO_NR-1;
/* Default gets normal, not minimum */
//icls->unused = IOPRIO_NORM;
/* Compute shares in abstract units */
icls->shares.total_guarantee = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
- temp = (u64) icls->ioprio * icls->shares.total_guarantee;
- do_div(temp, CKI_IOPRIO_DIV);
- icls->shares.my_guarantee = (int) temp;
-
- //icls->shares.my_limit = CKRM_SHARE_DFLT_MAX_LIMIT;
- //icls->shares.max_limit = CKRM_SHARE_DFLT_MAX_LIMIT;
- icls->shares.my_limit = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
- icls->shares.max_limit = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
+ // my_guarantee for root is meaningless. Set to default
+ icls->shares.my_guarantee = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
icls->shares.unused_guarantee =
- icls->shares.total_guarantee -
- icls->shares.my_guarantee;
- //icls->shares.cur_max_limit = CKRM_SHARE_DFLT_MAX_LIMIT;
+ CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
+
+ //temp = (u64) icls->cnt_unused * icls->shares.total_guarantee;
+ //do_div(temp, CKI_IOPRIO_DIV);
+ // temp now has root's default's share
+ //icls->shares.unused_guarantee =
+ // icls->shares.total_guarantee - temp;
+
+ icls->shares.my_limit = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
+ icls->shares.max_limit = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
icls->shares.cur_max_limit = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
} else {
init_icls_one(icls);
+ /* No propagation to parent needed if icls'
+ initial share is zero */
}
try_module_get(THIS_MODULE);
return icls;
/* Update parent's shares */
spin_lock(&parres->shares_lock);
child_guarantee_changed(&parres->shares, icls->shares.my_guarantee, 0);
- parres->unused += icls->ioprio;
+ parres->cnt_unused += icls->cnt_guarantee;
spin_unlock(&parres->shares_lock);
kfree(res);
/* limits not supported */
if ((new->max_limit != CKRM_SHARE_UNCHANGED)
|| (new->my_limit != CKRM_SHARE_UNCHANGED)) {
- printk(KERN_ERR "limits changed max_limit %d my_limit %d\n",
- new->max_limit, new->my_limit);
-
+ printk(KERN_ERR "limits not supported\n");
return -EINVAL;
}
}
rc = set_shares(new, cur, par);
-
printk(KERN_ERR "rc from set_shares %d\n", rc);
- if (!rc) {
+ if ((!rc) && parres) {
+
+ if (parres->cnt_guarantee == CKRM_SHARE_DONTCARE) {
+ parres->cnt_unused = CKRM_SHARE_DONTCARE;
+ } else if (par->total_guarantee) {
+ u64 temp = (u64) par->unused_guarantee *
+ parres->cnt_guarantee;
+ do_div(temp, par->total_guarantee);
+ parres->cnt_unused = (int) temp;
+ } else {
+ parres->cnt_unused = 0;
+ }
+ cki_recalc_propagate(res, parres);
+
+#if 0
int old = icls->ioprio;
+
rc = cki_recalc(icls,0);
if (!rc && parres) {
int raise_tot = icls->ioprio - old ;
- parres->unused += raise_tot ;
+ parres->unused -= raise_tot ;
}
+#endif
}
spin_unlock(&icls->shares_lock);
if (icls->parent) {
seq_printf(sfile, "%d total_write\n",atomic_read(&icls->stats.blkwr));
*/
- seq_printf(sfile, "%d ioprio\n",icls->ioprio);
- seq_printf(sfile, "%d unused\n",icls->unused);
+ seq_printf(sfile, "%d total ioprio\n",icls->cnt_guarantee);
+ seq_printf(sfile, "%d unused/default ioprio\n",icls->cnt_unused);
return 0;
}
resid = ckrm_register_res_ctlr(clstype, &cki_rcbs);
if (resid != -1) {
cki_rcbs.classtype = clstype;
- cki_cfq_set(cki_icls_tsk,cki_icls_ioprio);
+ cki_cfq_set(cki_tsk_icls,cki_tsk_ioprio);
}
}
git://git.onelab.eu / linux-2.6.git / commitdiff