Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6 and git://git.infradea...
[pandora-kernel.git] / block / cfq-iosched.c
index ae21919..a33bd43 100644 (file)
@@ -87,9 +87,10 @@ struct cfq_rb_root {
        unsigned count;
        unsigned total_weight;
        u64 min_vdisktime;
+       struct cfq_ttime ttime;
 };
-#define CFQ_RB_ROOT    (struct cfq_rb_root) { .rb = RB_ROOT, .left = NULL, \
-                       .count = 0, .min_vdisktime = 0, }
+#define CFQ_RB_ROOT    (struct cfq_rb_root) { .rb = RB_ROOT, \
+                       .ttime = {.last_end_request = jiffies,},}
 
 /*
  * Per process-grouping structure
@@ -136,7 +137,7 @@ struct cfq_queue {
 
        /* io prio of this group */
        unsigned short ioprio, org_ioprio;
-       unsigned short ioprio_class, org_ioprio_class;
+       unsigned short ioprio_class;
 
        pid_t pid;
 
@@ -212,6 +213,7 @@ struct cfq_group {
 #endif
        /* number of requests that are on the dispatch list or inside driver */
        int dispatched;
+       struct cfq_ttime ttime;
 };
 
 /*
@@ -393,6 +395,18 @@ CFQ_CFQQ_FNS(wait_busy);
                        j++, st = i < IDLE_WORKLOAD ? \
                        &cfqg->service_trees[i][j]: NULL) \
 
+static inline bool cfq_io_thinktime_big(struct cfq_data *cfqd,
+       struct cfq_ttime *ttime, bool group_idle)
+{
+       unsigned long slice;
+       if (!sample_valid(ttime->ttime_samples))
+               return false;
+       if (group_idle)
+               slice = cfqd->cfq_group_idle;
+       else
+               slice = cfqd->cfq_slice_idle;
+       return ttime->ttime_mean > slice;
+}
 
 static inline bool iops_mode(struct cfq_data *cfqd)
 {
@@ -1005,8 +1019,8 @@ static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg)
        return NULL;
 }
 
-void cfq_update_blkio_group_weight(void *key, struct blkio_group *blkg,
-                                       unsigned int weight)
+static void cfq_update_blkio_group_weight(void *key, struct blkio_group *blkg,
+                                         unsigned int weight)
 {
        struct cfq_group *cfqg = cfqg_of_blkg(blkg);
        cfqg->new_weight = weight;
@@ -1059,6 +1073,8 @@ static struct cfq_group * cfq_alloc_cfqg(struct cfq_data *cfqd)
                *st = CFQ_RB_ROOT;
        RB_CLEAR_NODE(&cfqg->rb_node);
 
+       cfqg->ttime.last_end_request = jiffies;
+
        /*
         * Take the initial reference that will be released on destroy
         * This can be thought of a joint reference by cgroup and
@@ -1198,6 +1214,9 @@ static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg)
 
        hlist_del_init(&cfqg->cfqd_node);
 
+       BUG_ON(cfqd->nr_blkcg_linked_grps <= 0);
+       cfqd->nr_blkcg_linked_grps--;
+
        /*
         * Put the reference taken at the time of creation so that when all
         * queues are gone, group can be destroyed.
@@ -1235,7 +1254,7 @@ static void cfq_release_cfq_groups(struct cfq_data *cfqd)
  * it should not be NULL as even if elevator was exiting, cgroup deltion
  * path got to it first.
  */
-void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg)
+static void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg)
 {
        unsigned long  flags;
        struct cfq_data *cfqd = key;
@@ -1502,16 +1521,11 @@ static void cfq_add_rq_rb(struct request *rq)
 {
        struct cfq_queue *cfqq = RQ_CFQQ(rq);
        struct cfq_data *cfqd = cfqq->cfqd;
-       struct request *__alias, *prev;
+       struct request *prev;
 
        cfqq->queued[rq_is_sync(rq)]++;
 
-       /*
-        * looks a little odd, but the first insert might return an alias.
-        * if that happens, put the alias on the dispatch list
-        */
-       while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL)
-               cfq_dispatch_insert(cfqd->queue, __alias);
+       elv_rb_add(&cfqq->sort_list, rq);
 
        if (!cfq_cfqq_on_rr(cfqq))
                cfq_add_cfqq_rr(cfqd, cfqq);
@@ -1969,7 +1983,8 @@ static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
         * Otherwise, we do only if they are the last ones
         * in their service tree.
         */
-       if (service_tree->count == 1 && cfq_cfqq_sync(cfqq))
+       if (service_tree->count == 1 && cfq_cfqq_sync(cfqq) &&
+          !cfq_io_thinktime_big(cfqd, &service_tree->ttime, false))
                return true;
        cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d",
                        service_tree->count);
@@ -2022,10 +2037,10 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
         * slice, then don't idle. This avoids overrunning the allotted
         * time slice.
         */
-       if (sample_valid(cic->ttime_samples) &&
-           (cfqq->slice_end - jiffies < cic->ttime_mean)) {
+       if (sample_valid(cic->ttime.ttime_samples) &&
+           (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) {
                cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%lu",
-                            cic->ttime_mean);
+                            cic->ttime.ttime_mean);
                return;
        }
 
@@ -2381,8 +2396,9 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
         * this group, wait for requests to complete.
         */
 check_group_idle:
-       if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1
-           && cfqq->cfqg->dispatched) {
+       if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1 &&
+           cfqq->cfqg->dispatched &&
+           !cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) {
                cfqq = NULL;
                goto keep_queue;
        }
@@ -2833,7 +2849,7 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
        cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO,
                                                        cfqd->queue->node);
        if (cic) {
-               cic->last_end_request = jiffies;
+               cic->ttime.last_end_request = jiffies;
                INIT_LIST_HEAD(&cic->queue_list);
                INIT_HLIST_NODE(&cic->cic_list);
                cic->dtor = cfq_free_io_context;
@@ -2883,7 +2899,6 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc)
         * elevate the priority of this queue
         */
        cfqq->org_ioprio = cfqq->ioprio;
-       cfqq->org_ioprio_class = cfqq->ioprio_class;
        cfq_clear_cfqq_prio_changed(cfqq);
 }
 
@@ -3221,14 +3236,28 @@ err:
 }
 
 static void
-cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic)
+__cfq_update_io_thinktime(struct cfq_ttime *ttime, unsigned long slice_idle)
 {
-       unsigned long elapsed = jiffies - cic->last_end_request;
-       unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle);
+       unsigned long elapsed = jiffies - ttime->last_end_request;
+       elapsed = min(elapsed, 2UL * slice_idle);
 
-       cic->ttime_samples = (7*cic->ttime_samples + 256) / 8;
-       cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8;
-       cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples;
+       ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8;
+       ttime->ttime_total = (7*ttime->ttime_total + 256*elapsed) / 8;
+       ttime->ttime_mean = (ttime->ttime_total + 128) / ttime->ttime_samples;
+}
+
+static void
+cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_queue *cfqq,
+       struct cfq_io_context *cic)
+{
+       if (cfq_cfqq_sync(cfqq)) {
+               __cfq_update_io_thinktime(&cic->ttime, cfqd->cfq_slice_idle);
+               __cfq_update_io_thinktime(&cfqq->service_tree->ttime,
+                       cfqd->cfq_slice_idle);
+       }
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+       __cfq_update_io_thinktime(&cfqq->cfqg->ttime, cfqd->cfq_group_idle);
+#endif
 }
 
 static void
@@ -3277,8 +3306,8 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq,
        else if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle ||
            (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq)))
                enable_idle = 0;
-       else if (sample_valid(cic->ttime_samples)) {
-               if (cic->ttime_mean > cfqd->cfq_slice_idle)
+       else if (sample_valid(cic->ttime.ttime_samples)) {
+               if (cic->ttime.ttime_mean > cfqd->cfq_slice_idle)
                        enable_idle = 0;
                else
                        enable_idle = 1;
@@ -3413,7 +3442,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
        if (rq->cmd_flags & REQ_META)
                cfqq->meta_pending++;
 
-       cfq_update_io_thinktime(cfqd, cic);
+       cfq_update_io_thinktime(cfqd, cfqq, cic);
        cfq_update_io_seektime(cfqd, cfqq, rq);
        cfq_update_idle_window(cfqd, cfqq, cic);
 
@@ -3520,12 +3549,16 @@ static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq)
        if (cfqq->cfqg->nr_cfqq > 1)
                return false;
 
+       /* the only queue in the group, but think time is big */
+       if (cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true))
+               return false;
+
        if (cfq_slice_used(cfqq))
                return true;
 
        /* if slice left is less than think time, wait busy */
-       if (cic && sample_valid(cic->ttime_samples)
-           && (cfqq->slice_end - jiffies < cic->ttime_mean))
+       if (cic && sample_valid(cic->ttime.ttime_samples)
+           && (cfqq->slice_end - jiffies < cic->ttime.ttime_mean))
                return true;
 
        /*
@@ -3566,11 +3599,24 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
        cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
 
        if (sync) {
-               RQ_CIC(rq)->last_end_request = now;
+               struct cfq_rb_root *service_tree;
+
+               RQ_CIC(rq)->ttime.last_end_request = now;
+
+               if (cfq_cfqq_on_rr(cfqq))
+                       service_tree = cfqq->service_tree;
+               else
+                       service_tree = service_tree_for(cfqq->cfqg,
+                               cfqq_prio(cfqq), cfqq_type(cfqq));
+               service_tree->ttime.last_end_request = now;
                if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now))
                        cfqd->last_delayed_sync = now;
        }
 
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+       cfqq->cfqg->ttime.last_end_request = now;
+#endif
+
        /*
         * If this is the active queue, check if it needs to be expired,
         * or if we want to idle in case it has no pending requests.
@@ -3616,30 +3662,6 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
                cfq_schedule_dispatch(cfqd);
 }
 
-/*
- * we temporarily boost lower priority queues if they are holding fs exclusive
- * resources. they are boosted to normal prio (CLASS_BE/4)
- */
-static void cfq_prio_boost(struct cfq_queue *cfqq)
-{
-       if (has_fs_excl()) {
-               /*
-                * boost idle prio on transactions that would lock out other
-                * users of the filesystem
-                */
-               if (cfq_class_idle(cfqq))
-                       cfqq->ioprio_class = IOPRIO_CLASS_BE;
-               if (cfqq->ioprio > IOPRIO_NORM)
-                       cfqq->ioprio = IOPRIO_NORM;
-       } else {
-               /*
-                * unboost the queue (if needed)
-                */
-               cfqq->ioprio_class = cfqq->org_ioprio_class;
-               cfqq->ioprio = cfqq->org_ioprio;
-       }
-}
-
 static inline int __cfq_may_queue(struct cfq_queue *cfqq)
 {
        if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) {
@@ -3670,7 +3692,6 @@ static int cfq_may_queue(struct request_queue *q, int rw)
        cfqq = cic_to_cfqq(cic, rw_is_sync(rw));
        if (cfqq) {
                cfq_init_prio_data(cfqq, cic->ioc);
-               cfq_prio_boost(cfqq);
 
                return __cfq_may_queue(cfqq);
        }