From: Vivek Goyal Date: Thu, 3 Dec 2009 17:59:38 +0000 (-0500) Subject: blkio: Introduce the notion of cfq groups X-Git-Tag: v2.6.33-rc1~379^2~31 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=cdb16e8f739985b8a5c9f4569b026583bbcd01a5 blkio: Introduce the notion of cfq groups o This patch introduce the notion of cfq groups. Soon we will can have multiple groups of different weights in the system. o Various service trees (prioclass and workload type trees), will become per cfq group. So hierarchy looks as follows. cfq_groups | workload type | cfq queue o When an scheduling decision has to be taken, first we select the cfq group then workload with-in the group and then cfq queue with-in the workload type. o This patch just makes various workload service tree per cfq group and introduce the function to be able to choose a group for scheduling. Signed-off-by: Vivek Goyal Signed-off-by: Jens Axboe --- diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 15b5361..a4d1726 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -132,6 +132,7 @@ struct cfq_queue { struct cfq_rb_root *service_tree; struct cfq_queue *new_cfqq; + struct cfq_group *cfqg; }; /* @@ -153,25 +154,30 @@ enum wl_type_t { SYNC_WORKLOAD = 2 }; +/* This is per cgroup per device grouping structure */ +struct cfq_group { + /* + * rr lists of queues with requests, onle rr for each priority class. + * Counts are embedded in the cfq_rb_root + */ + struct cfq_rb_root service_trees[2][3]; + struct cfq_rb_root service_tree_idle; +}; /* * Per block device queue structure */ struct cfq_data { struct request_queue *queue; + struct cfq_group root_group; /* - * rr lists of queues with requests, onle rr for each priority class. - * Counts are embedded in the cfq_rb_root - */ - struct cfq_rb_root service_trees[2][3]; - struct cfq_rb_root service_tree_idle; - /* * The priority currently being served */ enum wl_prio_t serving_prio; enum wl_type_t serving_type; unsigned long workload_expires; + struct cfq_group *serving_group; bool noidle_tree_requires_idle; /* @@ -240,14 +246,15 @@ struct cfq_data { unsigned long last_end_sync_rq; }; -static struct cfq_rb_root *service_tree_for(enum wl_prio_t prio, +static struct cfq_rb_root *service_tree_for(struct cfq_group *cfqg, + enum wl_prio_t prio, enum wl_type_t type, struct cfq_data *cfqd) { if (prio == IDLE_WORKLOAD) - return &cfqd->service_tree_idle; + return &cfqg->service_tree_idle; - return &cfqd->service_trees[prio][type]; + return &cfqg->service_trees[prio][type]; } enum cfqq_state_flags { @@ -317,12 +324,14 @@ static enum wl_type_t cfqq_type(struct cfq_queue *cfqq) static inline int cfq_busy_queues_wl(enum wl_prio_t wl, struct cfq_data *cfqd) { + struct cfq_group *cfqg = &cfqd->root_group; + if (wl == IDLE_WORKLOAD) - return cfqd->service_tree_idle.count; + return cfqg->service_tree_idle.count; - return cfqd->service_trees[wl][ASYNC_WORKLOAD].count - + cfqd->service_trees[wl][SYNC_NOIDLE_WORKLOAD].count - + cfqd->service_trees[wl][SYNC_WORKLOAD].count; + return cfqg->service_trees[wl][ASYNC_WORKLOAD].count + + cfqg->service_trees[wl][SYNC_NOIDLE_WORKLOAD].count + + cfqg->service_trees[wl][SYNC_WORKLOAD].count; } static void cfq_dispatch_insert(struct request_queue *, struct request *); @@ -612,7 +621,7 @@ static unsigned long cfq_slice_offset(struct cfq_data *cfqd, /* * just an approximation, should be ok. */ - return (cfqd->busy_queues - 1) * (cfq_prio_slice(cfqd, 1, 0) - + return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); } @@ -630,7 +639,8 @@ static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, struct cfq_rb_root *service_tree; int left; - service_tree = service_tree_for(cfqq_prio(cfqq), cfqq_type(cfqq), cfqd); + service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq), + cfqq_type(cfqq), cfqd); if (cfq_class_idle(cfqq)) { rb_key = CFQ_IDLE_DELAY; parent = rb_last(&service_tree->rb); @@ -1066,7 +1076,8 @@ static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out) static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) { struct cfq_rb_root *service_tree = - service_tree_for(cfqd->serving_prio, cfqd->serving_type, cfqd); + service_tree_for(cfqd->serving_group, cfqd->serving_prio, + cfqd->serving_type, cfqd); if (RB_EMPTY_ROOT(&service_tree->rb)) return NULL; @@ -1218,7 +1229,8 @@ static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) * in their service tree. */ if (!service_tree) - service_tree = service_tree_for(prio, cfqq_type(cfqq), cfqd); + service_tree = service_tree_for(cfqq->cfqg, prio, + cfqq_type(cfqq), cfqd); if (service_tree->count == 0) return true; @@ -1377,8 +1389,9 @@ static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) } } -static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, enum wl_prio_t prio, - bool prio_changed) +static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, + struct cfq_group *cfqg, enum wl_prio_t prio, + bool prio_changed) { struct cfq_queue *queue; int i; @@ -1392,10 +1405,10 @@ static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, enum wl_prio_t prio, * from SYNC_NOIDLE (first choice), or just SYNC * over ASYNC */ - if (service_tree_for(prio, cur_best, cfqd)->count) + if (service_tree_for(cfqg, prio, cur_best, cfqd)->count) return cur_best; cur_best = SYNC_WORKLOAD; - if (service_tree_for(prio, cur_best, cfqd)->count) + if (service_tree_for(cfqg, prio, cur_best, cfqd)->count) return cur_best; return ASYNC_WORKLOAD; @@ -1403,7 +1416,7 @@ static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, enum wl_prio_t prio, for (i = 0; i < 3; ++i) { /* otherwise, select the one with lowest rb_key */ - queue = cfq_rb_first(service_tree_for(prio, i, cfqd)); + queue = cfq_rb_first(service_tree_for(cfqg, prio, i, cfqd)); if (queue && (!key_valid || time_before(queue->rb_key, lowest_key))) { lowest_key = queue->rb_key; @@ -1415,12 +1428,13 @@ static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, enum wl_prio_t prio, return cur_best; } -static void choose_service_tree(struct cfq_data *cfqd) +static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg) { enum wl_prio_t previous_prio = cfqd->serving_prio; bool prio_changed; unsigned slice; unsigned count; + struct cfq_rb_root *st; /* Choose next priority. RT > BE > IDLE */ if (cfq_busy_queues_wl(RT_WORKLOAD, cfqd)) @@ -1439,8 +1453,9 @@ static void choose_service_tree(struct cfq_data *cfqd) * expiration time */ prio_changed = (cfqd->serving_prio != previous_prio); - count = service_tree_for(cfqd->serving_prio, cfqd->serving_type, cfqd) - ->count; + st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type, + cfqd); + count = st->count; /* * If priority didn't change, check workload expiration, @@ -1452,9 +1467,10 @@ static void choose_service_tree(struct cfq_data *cfqd) /* otherwise select new workload type */ cfqd->serving_type = - cfq_choose_wl(cfqd, cfqd->serving_prio, prio_changed); - count = service_tree_for(cfqd->serving_prio, cfqd->serving_type, cfqd) - ->count; + cfq_choose_wl(cfqd, cfqg, cfqd->serving_prio, prio_changed); + st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type, + cfqd); + count = st->count; /* * the workload slice is computed as a fraction of target latency @@ -1478,6 +1494,12 @@ static void choose_service_tree(struct cfq_data *cfqd) cfqd->noidle_tree_requires_idle = false; } +static void cfq_choose_cfqg(struct cfq_data *cfqd) +{ + cfqd->serving_group = &cfqd->root_group; + choose_service_tree(cfqd, &cfqd->root_group); +} + /* * Select a queue for service. If we have a current active queue, * check whether to continue servicing it, or retrieve and set a new one. @@ -1535,7 +1557,7 @@ new_queue: * service tree */ if (!new_cfqq) - choose_service_tree(cfqd); + cfq_choose_cfqg(cfqd); cfqq = cfq_set_active_queue(cfqd, new_cfqq); keep_queue: @@ -1564,13 +1586,15 @@ static int cfq_forced_dispatch(struct cfq_data *cfqd) struct cfq_queue *cfqq; int dispatched = 0; int i, j; + struct cfq_group *cfqg = &cfqd->root_group; + for (i = 0; i < 2; ++i) for (j = 0; j < 3; ++j) - while ((cfqq = cfq_rb_first(&cfqd->service_trees[i][j])) + while ((cfqq = cfq_rb_first(&cfqg->service_trees[i][j])) != NULL) dispatched += __cfq_forced_dispatch_cfqq(cfqq); - while ((cfqq = cfq_rb_first(&cfqd->service_tree_idle)) != NULL) + while ((cfqq = cfq_rb_first(&cfqg->service_tree_idle)) != NULL) dispatched += __cfq_forced_dispatch_cfqq(cfqq); cfq_slice_expired(cfqd, 0); @@ -2041,14 +2065,26 @@ static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, cfqq->pid = pid; } +static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) +{ + cfqq->cfqg = cfqg; +} + +static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create) +{ + return &cfqd->root_group; +} + static struct cfq_queue * cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc, gfp_t gfp_mask) { struct cfq_queue *cfqq, *new_cfqq = NULL; struct cfq_io_context *cic; + struct cfq_group *cfqg; retry: + cfqg = cfq_get_cfqg(cfqd, 1); cic = cfq_cic_lookup(cfqd, ioc); /* cic always exists here */ cfqq = cic_to_cfqq(cic, is_sync); @@ -2079,6 +2115,7 @@ retry: if (cfqq) { cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); cfq_init_prio_data(cfqq, ioc); + cfq_link_cfqq_cfqg(cfqq, cfqg); cfq_log_cfqq(cfqd, cfqq, "alloced"); } else cfqq = &cfqd->oom_cfqq; @@ -2931,15 +2968,19 @@ static void *cfq_init_queue(struct request_queue *q) { struct cfq_data *cfqd; int i, j; + struct cfq_group *cfqg; cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); if (!cfqd) return NULL; + /* Init root group */ + cfqg = &cfqd->root_group; + for (i = 0; i < 2; ++i) for (j = 0; j < 3; ++j) - cfqd->service_trees[i][j] = CFQ_RB_ROOT; - cfqd->service_tree_idle = CFQ_RB_ROOT; + cfqg->service_trees[i][j] = CFQ_RB_ROOT; + cfqg->service_tree_idle = CFQ_RB_ROOT; /* * Not strictly needed (since RB_ROOT just clears the node and we @@ -2956,6 +2997,7 @@ static void *cfq_init_queue(struct request_queue *q) */ cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); atomic_inc(&cfqd->oom_cfqq.ref); + cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group); INIT_LIST_HEAD(&cfqd->cic_list);