diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/cfq-iosched.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 84887e2eb210..55d2a21f7f06 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -115,6 +115,10 @@ struct cfq_queue { /* fifo list of requests in sort_list */ struct list_head fifo; + /* time when queue got scheduled in to dispatch first request. */ + unsigned long dispatch_start; + /* time when first request from queue completed and slice started. */ + unsigned long slice_start; unsigned long slice_end; long slice_resid; unsigned int slice_dispatch; @@ -181,6 +185,10 @@ struct cfq_group { */ struct cfq_rb_root service_trees[2][3]; struct cfq_rb_root service_tree_idle; + + unsigned long saved_workload_slice; + enum wl_type_t saved_workload; + enum wl_prio_t saved_serving_prio; }; /* @@ -543,6 +551,7 @@ cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) low_slice); } } + cfqq->slice_start = jiffies; cfqq->slice_end = jiffies + slice; cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); } @@ -818,6 +827,58 @@ cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg) st->total_weight -= cfqg->weight; if (!RB_EMPTY_NODE(&cfqg->rb_node)) cfq_rb_erase(&cfqg->rb_node, st); + cfqg->saved_workload_slice = 0; +} + +static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq) +{ + unsigned int slice_used, allocated_slice; + + /* + * Queue got expired before even a single request completed or + * got expired immediately after first request completion. + */ + if (!cfqq->slice_start || cfqq->slice_start == jiffies) { + /* + * Also charge the seek time incurred to the group, otherwise + * if there are mutiple queues in the group, each can dispatch + * a single request on seeky media and cause lots of seek time + * and group will never know it. + */ + slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start), + 1); + } else { + slice_used = jiffies - cfqq->slice_start; + allocated_slice = cfqq->slice_end - cfqq->slice_start; + if (slice_used > allocated_slice) + slice_used = allocated_slice; + } + + 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_rb_root *st = &cfqd->grp_service_tree; + unsigned int used_sl; + + used_sl = cfq_cfqq_slice_usage(cfqq); + + /* Can't update vdisktime while group is on service tree */ + cfq_rb_erase(&cfqg->rb_node, st); + cfqg->vdisktime += cfq_scale_slice(used_sl, cfqg); + __cfq_group_service_tree_add(st, cfqg); + + /* This group is being expired. Save the context */ + if (time_after(cfqd->workload_expires, jiffies)) { + cfqg->saved_workload_slice = cfqd->workload_expires + - jiffies; + cfqg->saved_workload = cfqd->serving_type; + cfqg->saved_serving_prio = cfqd->serving_prio; + } else + cfqg->saved_workload_slice = 0; } /* @@ -833,6 +894,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, unsigned long rb_key; struct cfq_rb_root *service_tree; int left; + int new_cfqq = 1; service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq), cfqq_type(cfqq), cfqd); @@ -861,6 +923,7 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, } if (!RB_EMPTY_NODE(&cfqq->rb_node)) { + new_cfqq = 0; /* * same position, nothing more to do */ @@ -902,6 +965,8 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, rb_link_node(&cfqq->rb_node, parent, p); rb_insert_color(&cfqq->rb_node, &service_tree->rb); service_tree->count++; + if (add_front || !new_cfqq) + return; cfq_group_service_tree_add(cfqd, cfqq->cfqg); } @@ -1218,6 +1283,8 @@ static void __cfq_set_active_queue(struct cfq_data *cfqd, { if (cfqq) { cfq_log_cfqq(cfqd, cfqq, "set_active"); + cfqq->slice_start = 0; + cfqq->dispatch_start = jiffies; cfqq->slice_end = 0; cfqq->slice_dispatch = 0; @@ -1255,6 +1322,8 @@ __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); + if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) cfq_del_cfqq_rr(cfqd, cfqq); @@ -1263,6 +1332,9 @@ __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, if (cfqq == cfqd->active_queue) cfqd->active_queue = NULL; + if (&cfqq->cfqg->rb_node == cfqd->grp_service_tree.active) + cfqd->grp_service_tree.active = NULL; + if (cfqd->active_cic) { put_io_context(cfqd->active_cic->ioc); cfqd->active_cic = NULL; @@ -1747,6 +1819,13 @@ static void cfq_choose_cfqg(struct cfq_data *cfqd) struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); cfqd->serving_group = cfqg; + + /* Restore the workload type data */ + if (cfqg->saved_workload_slice) { + cfqd->workload_expires = jiffies + cfqg->saved_workload_slice; + cfqd->serving_type = cfqg->saved_workload; + cfqd->serving_prio = cfqg->saved_serving_prio; + } choose_service_tree(cfqd, cfqg); } |