blkio: Initialize blkg->stats_lock for the root cfqg too
[pandora-kernel.git] / block / cfq-iosched.c
index dee9d93..62defd0 100644 (file)
@@ -7,6 +7,7 @@
  *  Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
  */
 #include <linux/module.h>
+#include <linux/slab.h>
 #include <linux/blkdev.h>
 #include <linux/elevator.h>
 #include <linux/jiffies.h>
@@ -47,6 +48,7 @@ static const int cfq_hist_divisor = 4;
 #define CFQ_SERVICE_SHIFT       12
 
 #define CFQQ_SEEK_THR          (sector_t)(8 * 100)
+#define CFQQ_CLOSE_THR         (sector_t)(8 * 1024)
 #define CFQQ_SECT_THR_NONROT   (sector_t)(2 * 32)
 #define CFQQ_SEEKY(cfqq)       (hweight32(cfqq->seek_history) > 32/8)
 
@@ -141,8 +143,6 @@ struct cfq_queue {
        struct cfq_queue *new_cfqq;
        struct cfq_group *cfqg;
        struct cfq_group *orig_cfqg;
-       /* Sectors dispatched in current dispatch round */
-       unsigned long nr_sectors;
 };
 
 /*
@@ -856,7 +856,7 @@ cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
        if (!RB_EMPTY_NODE(&cfqg->rb_node))
                cfq_rb_erase(&cfqg->rb_node, st);
        cfqg->saved_workload_slice = 0;
-       blkiocg_update_blkio_group_dequeue_stats(&cfqg->blkg, 1);
+       blkiocg_update_dequeue_stats(&cfqg->blkg, 1);
 }
 
 static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq)
@@ -882,13 +882,12 @@ static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq)
                        slice_used = cfqq->allocated_slice;
        }
 
-       cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u sect=%lu", slice_used,
-                               cfqq->nr_sectors);
+       cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u", slice_used);
        return slice_used;
 }
 
 static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
-                               struct cfq_queue *cfqq)
+                               struct cfq_queue *cfqq, bool forced)
 {
        struct cfq_rb_root *st = &cfqd->grp_service_tree;
        unsigned int used_sl, charge_sl;
@@ -917,8 +916,8 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
 
        cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
                                        st->min_vdisktime);
-       blkiocg_update_blkio_group_stats(&cfqg->blkg, used_sl,
-                                               cfqq->nr_sectors);
+       blkiocg_update_timeslice_used(&cfqg->blkg, used_sl);
+       blkiocg_set_start_empty_time(&cfqg->blkg, forced);
 }
 
 #ifdef CONFIG_CFQ_GROUP_IOSCHED
@@ -947,6 +946,11 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
        unsigned int major, minor;
 
        cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
+       if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) {
+               sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
+               cfqg->blkg.dev = MKDEV(major, minor);
+               goto done;
+       }
        if (cfqg || !create)
                goto done;
 
@@ -954,7 +958,6 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
        if (!cfqg)
                goto done;
 
-       cfqg->weight = blkcg->weight;
        for_each_cfqg_st(cfqg, i, j, st)
                *st = CFQ_RB_ROOT;
        RB_CLEAR_NODE(&cfqg->rb_node);
@@ -971,6 +974,7 @@ cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create)
        sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor);
        blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd,
                                        MKDEV(major, minor));
+       cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev);
 
        /* Add group on cfqd list */
        hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
@@ -1382,7 +1386,12 @@ 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)]--;
+       blkiocg_update_io_remove_stats(&cfqq->cfqg->blkg, rq_data_dir(rq),
+                                               rq_is_sync(rq));
        cfq_add_rq_rb(rq);
+       blkiocg_update_io_add_stats(
+                       &cfqq->cfqg->blkg, &cfqq->cfqd->serving_group->blkg,
+                       rq_data_dir(rq), rq_is_sync(rq));
 }
 
 static struct request *
@@ -1438,6 +1447,8 @@ static void cfq_remove_request(struct request *rq)
        cfq_del_rq_rb(rq);
 
        cfqq->cfqd->rq_queued--;
+       blkiocg_update_io_remove_stats(&cfqq->cfqg->blkg, rq_data_dir(rq),
+                                               rq_is_sync(rq));
        if (rq_is_meta(rq)) {
                WARN_ON(!cfqq->meta_pending);
                cfqq->meta_pending--;
@@ -1469,6 +1480,14 @@ static void cfq_merged_request(struct request_queue *q, struct request *req,
        }
 }
 
+static void cfq_bio_merged(struct request_queue *q, struct request *req,
+                               struct bio *bio)
+{
+       struct cfq_queue *cfqq = RQ_CFQQ(req);
+       blkiocg_update_io_merged_stats(&cfqq->cfqg->blkg, bio_data_dir(bio),
+                                       cfq_bio_sync(bio));
+}
+
 static void
 cfq_merged_requests(struct request_queue *q, struct request *rq,
                    struct request *next)
@@ -1486,6 +1505,8 @@ cfq_merged_requests(struct request_queue *q, struct request *rq,
        if (cfqq->next_rq == next)
                cfqq->next_rq = rq;
        cfq_remove_request(next);
+       blkiocg_update_io_merged_stats(&cfqq->cfqg->blkg, rq_data_dir(next),
+                                       rq_is_sync(next));
 }
 
 static int cfq_allow_merge(struct request_queue *q, struct request *rq,
@@ -1513,17 +1534,24 @@ static int cfq_allow_merge(struct request_queue *q, struct request *rq,
        return cfqq == RQ_CFQQ(rq);
 }
 
+static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
+{
+       del_timer(&cfqd->idle_slice_timer);
+       blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg);
+}
+
 static void __cfq_set_active_queue(struct cfq_data *cfqd,
                                   struct cfq_queue *cfqq)
 {
        if (cfqq) {
-               cfq_log_cfqq(cfqd, cfqq, "set_active");
+               cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d",
+                               cfqd->serving_prio, cfqd->serving_type);
+               blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg);
                cfqq->slice_start = 0;
                cfqq->dispatch_start = jiffies;
                cfqq->allocated_slice = 0;
                cfqq->slice_end = 0;
                cfqq->slice_dispatch = 0;
-               cfqq->nr_sectors = 0;
 
                cfq_clear_cfqq_wait_request(cfqq);
                cfq_clear_cfqq_must_dispatch(cfqq);
@@ -1531,7 +1559,7 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd,
                cfq_clear_cfqq_fifo_expire(cfqq);
                cfq_mark_cfqq_slice_new(cfqq);
 
-               del_timer(&cfqd->idle_slice_timer);
+               cfq_del_timer(cfqd, cfqq);
        }
 
        cfqd->active_queue = cfqq;
@@ -1542,12 +1570,12 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd,
  */
 static void
 __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
-                   bool timed_out)
+                   bool timed_out, bool forced)
 {
        cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out);
 
        if (cfq_cfqq_wait_request(cfqq))
-               del_timer(&cfqd->idle_slice_timer);
+               cfq_del_timer(cfqd, cfqq);
 
        cfq_clear_cfqq_wait_request(cfqq);
        cfq_clear_cfqq_wait_busy(cfqq);
@@ -1569,7 +1597,7 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
                cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid);
        }
 
-       cfq_group_served(cfqd, cfqq->cfqg, cfqq);
+       cfq_group_served(cfqd, cfqq->cfqg, cfqq, forced);
 
        if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
                cfq_del_cfqq_rr(cfqd, cfqq);
@@ -1588,12 +1616,13 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq,
        }
 }
 
-static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out)
+static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out,
+                                       bool forced)
 {
        struct cfq_queue *cfqq = cfqd->active_queue;
 
        if (cfqq)
-               __cfq_slice_expired(cfqd, cfqq, timed_out);
+               __cfq_slice_expired(cfqd, cfqq, timed_out, forced);
 }
 
 /*
@@ -1660,9 +1689,9 @@ static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd,
 }
 
 static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq,
-                              struct request *rq, bool for_preempt)
+                              struct request *rq)
 {
-       return cfq_dist_from_last(cfqd, rq) <= CFQQ_SEEK_THR;
+       return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR;
 }
 
 static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
@@ -1689,7 +1718,7 @@ static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
         * will contain the closest sector.
         */
        __cfqq = rb_entry(parent, struct cfq_queue, p_node);
-       if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq, false))
+       if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
                return __cfqq;
 
        if (blk_rq_pos(__cfqq->next_rq) < sector)
@@ -1700,7 +1729,7 @@ static struct cfq_queue *cfqq_close(struct cfq_data *cfqd,
                return NULL;
 
        __cfqq = rb_entry(node, struct cfq_queue, p_node);
-       if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq, false))
+       if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq))
                return __cfqq;
 
        return NULL;
@@ -1721,6 +1750,8 @@ static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd,
 {
        struct cfq_queue *cfqq;
 
+       if (cfq_class_idle(cur_cfqq))
+               return NULL;
        if (!cfq_cfqq_sync(cur_cfqq))
                return NULL;
        if (CFQQ_SEEKY(cur_cfqq))
@@ -1787,7 +1818,11 @@ 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.
         */
-       return service_tree->count == 1 && cfq_cfqq_sync(cfqq);
+       if (service_tree->count == 1 && cfq_cfqq_sync(cfqq))
+               return 1;
+       cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d",
+                       service_tree->count);
+       return 0;
 }
 
 static void cfq_arm_slice_timer(struct cfq_data *cfqd)
@@ -1832,14 +1867,18 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
         * time slice.
         */
        if (sample_valid(cic->ttime_samples) &&
-           (cfqq->slice_end - jiffies < cic->ttime_mean))
+           (cfqq->slice_end - jiffies < cic->ttime_mean)) {
+               cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%d",
+                               cic->ttime_mean);
                return;
+       }
 
        cfq_mark_cfqq_wait_request(cfqq);
 
        sl = cfqd->cfq_slice_idle;
 
        mod_timer(&cfqd->idle_slice_timer, jiffies + sl);
+       blkiocg_update_set_idle_time_stats(&cfqq->cfqg->blkg);
        cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl);
 }
 
@@ -1859,7 +1898,8 @@ static void cfq_dispatch_insert(struct request_queue *q, struct request *rq)
        elv_dispatch_sort(q, rq);
 
        cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++;
-       cfqq->nr_sectors += blk_rq_sectors(rq);
+       blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq),
+                                       rq_data_dir(rq), rq_is_sync(rq));
 }
 
 /*
@@ -2041,6 +2081,7 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
                slice = max(slice, 2 * cfqd->cfq_slice_idle);
 
        slice = max_t(unsigned, slice, CFQ_MIN_TT);
+       cfq_log(cfqd, "workload slice:%d", slice);
        cfqd->workload_expires = jiffies + slice;
        cfqd->noidle_tree_requires_idle = false;
 }
@@ -2149,7 +2190,7 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
        }
 
 expire:
-       cfq_slice_expired(cfqd, 0);
+       cfq_slice_expired(cfqd, 0, false);
 new_queue:
        /*
         * Current queue expired. Check if we have to switch to a new
@@ -2175,7 +2216,7 @@ static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq)
        BUG_ON(!list_empty(&cfqq->fifo));
 
        /* By default cfqq is not expired if it is empty. Do it explicitly */
-       __cfq_slice_expired(cfqq->cfqd, cfqq, 0);
+       __cfq_slice_expired(cfqq->cfqd, cfqq, 0, true);
        return dispatched;
 }
 
@@ -2188,10 +2229,13 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd)
        struct cfq_queue *cfqq;
        int dispatched = 0;
 
-       while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL)
+       /* Expire the timeslice of the current active queue first */
+       cfq_slice_expired(cfqd, 0, true);
+       while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) {
+               __cfq_set_active_queue(cfqd, cfqq);
                dispatched += __cfq_forced_dispatch_cfqq(cfqq);
+       }
 
-       cfq_slice_expired(cfqd, 0);
        BUG_ON(cfqd->busy_queues);
 
        cfq_log(cfqd, "forced_dispatch=%d", dispatched);
@@ -2355,7 +2399,7 @@ static int cfq_dispatch_requests(struct request_queue *q, int force)
            cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) ||
            cfq_class_idle(cfqq))) {
                cfqq->slice_end = jiffies + 1;
-               cfq_slice_expired(cfqd, 0);
+               cfq_slice_expired(cfqd, 0, false);
        }
 
        cfq_log_cfqq(cfqd, cfqq, "dispatched a request");
@@ -2386,7 +2430,7 @@ static void cfq_put_queue(struct cfq_queue *cfqq)
        orig_cfqg = cfqq->orig_cfqg;
 
        if (unlikely(cfqd->active_queue == cfqq)) {
-               __cfq_slice_expired(cfqd, cfqq, 0);
+               __cfq_slice_expired(cfqd, cfqq, 0, false);
                cfq_schedule_dispatch(cfqd);
        }
 
@@ -2487,7 +2531,7 @@ static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq)
        struct cfq_queue *__cfqq, *next;
 
        if (unlikely(cfqq == cfqd->active_queue)) {
-               __cfq_slice_expired(cfqd, cfqq, 0);
+               __cfq_slice_expired(cfqd, cfqq, 0, false);
                cfq_schedule_dispatch(cfqd);
        }
 
@@ -3103,7 +3147,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
         * if this request is as-good as one we would expect from the
         * current cfqq, let it preempt
         */
-       if (cfq_rq_close(cfqd, cfqq, rq, true))
+       if (cfq_rq_close(cfqd, cfqq, rq))
                return true;
 
        return false;
@@ -3116,7 +3160,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
 static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
        cfq_log_cfqq(cfqd, cfqq, "preempt");
-       cfq_slice_expired(cfqd, 1);
+       cfq_slice_expired(cfqd, 1, false);
 
        /*
         * Put the new queue at the front of the of the current list,
@@ -3164,11 +3208,14 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
                if (cfq_cfqq_wait_request(cfqq)) {
                        if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE ||
                            cfqd->busy_queues > 1) {
-                               del_timer(&cfqd->idle_slice_timer);
+                               cfq_del_timer(cfqd, cfqq);
                                cfq_clear_cfqq_wait_request(cfqq);
                                __blk_run_queue(cfqd->queue);
-                       } else
+                       } else {
+                               blkiocg_update_idle_time_stats(
+                                               &cfqq->cfqg->blkg);
                                cfq_mark_cfqq_must_dispatch(cfqq);
+                       }
                }
        } else if (cfq_should_preempt(cfqd, cfqq, rq)) {
                /*
@@ -3194,6 +3241,9 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq)
        list_add_tail(&rq->queuelist, &cfqq->fifo);
        cfq_add_rq_rb(rq);
 
+       blkiocg_update_io_add_stats(&cfqq->cfqg->blkg,
+                       &cfqd->serving_group->blkg, rq_data_dir(rq),
+                       rq_is_sync(rq));
        cfq_rq_enqueued(cfqd, cfqq, rq);
 }
 
@@ -3279,6 +3329,9 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
        WARN_ON(!cfqq->dispatched);
        cfqd->rq_in_driver--;
        cfqq->dispatched--;
+       blkiocg_update_completion_stats(&cfqq->cfqg->blkg, rq_start_time_ns(rq),
+                       rq_io_start_time_ns(rq), rq_data_dir(rq),
+                       rq_is_sync(rq));
 
        cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
 
@@ -3307,6 +3360,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
                if (cfq_should_wait_busy(cfqd, cfqq)) {
                        cfqq->slice_end = jiffies + cfqd->cfq_slice_idle;
                        cfq_mark_cfqq_wait_busy(cfqq);
+                       cfq_log_cfqq(cfqd, cfqq, "will busy wait");
                }
 
                /*
@@ -3318,7 +3372,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
                 * - when there is a close cooperator
                 */
                if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq))
-                       cfq_slice_expired(cfqd, 1);
+                       cfq_slice_expired(cfqd, 1, false);
                else if (sync && cfqq_empty &&
                         !cfq_close_cooperator(cfqd, cfqq)) {
                        cfqd->noidle_tree_requires_idle |= !rq_noidle(rq);
@@ -3578,7 +3632,7 @@ static void cfq_idle_slice_timer(unsigned long data)
                cfq_clear_cfqq_deep(cfqq);
        }
 expire:
-       cfq_slice_expired(cfqd, timed_out);
+       cfq_slice_expired(cfqd, timed_out, false);
 out_kick:
        cfq_schedule_dispatch(cfqd);
 out_cont:
@@ -3621,7 +3675,7 @@ static void cfq_exit_queue(struct elevator_queue *e)
        spin_lock_irq(q->queue_lock);
 
        if (cfqd->active_queue)
-               __cfq_slice_expired(cfqd, cfqd->active_queue, 0);
+               __cfq_slice_expired(cfqd, cfqd->active_queue, 0, false);
 
        while (!list_empty(&cfqd->cic_list)) {
                struct cfq_io_context *cic = list_entry(cfqd->cic_list.next,
@@ -3848,6 +3902,7 @@ static struct elevator_type iosched_cfq = {
                .elevator_merged_fn =           cfq_merged_request,
                .elevator_merge_req_fn =        cfq_merged_requests,
                .elevator_allow_merge_fn =      cfq_allow_merge,
+               .elevator_bio_merged_fn =       cfq_bio_merged,
                .elevator_dispatch_fn =         cfq_dispatch_requests,
                .elevator_add_req_fn =          cfq_insert_request,
                .elevator_activate_req_fn =     cfq_activate_request,