o Littile debugging aid for hierarchical IO scheduling. o Enabled under CONFIG_DEBUG_GROUP_IOSCHED
o Currently it outputs more debug messages in blktrace output which helps a great deal in debugging in hierarchical setup. Signed-off-by: Vivek Goyal <[email protected]> --- block/Kconfig.iosched | 10 +++- block/elevator-fq.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++-- block/elevator-fq.h | 6 ++ 3 files changed, 141 insertions(+), 6 deletions(-) diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched index 0677099..79f188c 100644 --- a/block/Kconfig.iosched +++ b/block/Kconfig.iosched @@ -140,6 +140,14 @@ config TRACK_ASYNC_CONTEXT request, original owner of the bio is decided by using io tracking patches otherwise we continue to attribute the request to the submitting thread. -endmenu +config DEBUG_GROUP_IOSCHED + bool "Debug Hierarchical Scheduling support" + depends on CGROUPS && GROUP_IOSCHED + default n + ---help--- + Enable some debugging hooks for hierarchical scheduling support. + Currently it just outputs more information in blktrace output. + +endmenu endif diff --git a/block/elevator-fq.c b/block/elevator-fq.c index 1dd0bb3..9500619 100644 --- a/block/elevator-fq.c +++ b/block/elevator-fq.c @@ -30,7 +30,7 @@ static int elv_rate_sampling_window = HZ / 10; #define IO_DEFAULT_GRP_CLASS IOPRIO_CLASS_BE #define IO_SERVICE_TREE_INIT ((struct io_service_tree) \ - { RB_ROOT, RB_ROOT, NULL, NULL, 0, 0 }) + { RB_ROOT, RB_ROOT, 0, NULL, NULL, 0, 0 }) static inline struct io_queue *elv_close_cooperator(struct request_queue *q, struct io_queue *ioq, int probe); @@ -118,6 +118,37 @@ static inline struct io_group *io_entity_to_iog(struct io_entity *entity) iog = container_of(entity, struct io_group, entity); return iog; } + +#ifdef CONFIG_DEBUG_GROUP_IOSCHED +static void io_group_path(struct io_group *iog, char *buf, int buflen) +{ + unsigned short id = iog->iocg_id; + struct cgroup_subsys_state *css; + + rcu_read_lock(); + + if (!id) + goto out; + + css = css_lookup(&io_subsys, id); + if (!css) + goto out; + + if (!css_tryget(css)) + goto out; + + cgroup_path(css->cgroup, buf, buflen); + + css_put(css); + + rcu_read_unlock(); + return; +out: + rcu_read_unlock(); + buf[0] = '\0'; + return; +} +#endif #else /* GROUP_IOSCHED */ #define for_each_entity(entity) \ for (; entity != NULL; entity = NULL) @@ -372,7 +403,7 @@ static void bfq_active_insert(struct io_service_tree *st, struct rb_node *node = &entity->rb_node; bfq_insert(&st->active, entity); - + st->nr_active++; if (node->rb_left != NULL) node = node->rb_left; else if (node->rb_right != NULL) @@ -434,7 +465,7 @@ static void bfq_active_extract(struct io_service_tree *st, node = bfq_find_deepest(&entity->rb_node); bfq_extract(&st->active, entity); - + st->nr_active--; if (node != NULL) bfq_update_active_tree(node); } @@ -1233,6 +1264,9 @@ struct io_group *io_group_chain_alloc(struct request_queue *q, void *key, io_group_init_entity(iocg, iog); iog->my_entity = &iog->entity; +#ifdef CONFIG_DEBUG_GROUP_IOSCHED + iog->iocg_id = css_id(&iocg->css); +#endif blk_init_request_list(&iog->rl); @@ -1506,6 +1540,9 @@ struct io_group *io_alloc_root_group(struct request_queue *q, /* elevator reference. */ elv_get_iog(iog); hlist_add_head_rcu(&iog->group_node, &iocg->group_data); +#ifdef CONFIG_DEBUG_GROUP_IOSCHED + iog->iocg_id = css_id(&iocg->css); +#endif spin_unlock_irq(&iocg->lock); return iog; @@ -1886,6 +1923,7 @@ struct cgroup_subsys io_subsys = { .destroy = iocg_destroy, .populate = iocg_populate, .subsys_id = io_subsys_id, + .use_id = 1, }; /* @@ -2203,6 +2241,25 @@ EXPORT_SYMBOL(elv_get_slice_idle); void elv_ioq_served(struct io_queue *ioq, bfq_service_t served) { entity_served(&ioq->entity, served, ioq->nr_sectors); + +#ifdef CONFIG_DEBUG_GROUP_IOSCHED + { + struct elv_fq_data *efqd = ioq->efqd; + char path[128]; + struct io_group *iog = ioq_to_io_group(ioq); + io_group_path(iog, path, sizeof(path)); + elv_log_ioq(efqd, ioq, "ioq served: QSt=0x%lx QSs=0x%lx" + " QTt=0x%lx QTs=0x%lx grp=%s GTt=0x%lx " + " GTs=0x%lx rq_queued=%d", + served, ioq->nr_sectors, + ioq->entity.total_service, + ioq->entity.total_sector_service, + path, + iog->entity.total_service, + iog->entity.total_sector_service, + ioq->nr_queued); + } +#endif } /* Tells whether ioq is queued in root group or not */ @@ -2671,11 +2728,34 @@ static void __elv_set_active_ioq(struct elv_fq_data *efqd, struct io_queue *ioq, if (ioq) { struct io_group *iog = ioq_to_io_group(ioq); + elv_log_ioq(efqd, ioq, "set_active, busy=%d ioprio=%d" - " weight=%ld group_weight=%ld", + " weight=%ld rq_queued=%d group_weight=%ld", efqd->busy_queues, ioq->entity.ioprio, ioq->entity.weight, - iog_weight(iog)); + ioq->nr_queued, iog_weight(iog)); + +#ifdef CONFIG_DEBUG_GROUP_IOSCHED + { + char path[128]; + struct io_service_tree *grpst; + int nr_active = 0; + if (iog != efqd->root_group) { + grpst = io_entity_service_tree( + &iog->entity); + nr_active = grpst->nr_active; + } + io_group_path(iog, path, sizeof(path)); + elv_log_ioq(efqd, ioq, "set_active, ioq grp=%s" + " nrgrps=%d QTt=0x%lx QTs=0x%lx GTt=0x%lx " + " GTs=0x%lx rq_queued=%d", path, nr_active, + ioq->entity.total_service, + ioq->entity.total_sector_service, + iog->entity.total_service, + iog->entity.total_sector_service, + ioq->nr_queued); + } +#endif ioq->slice_end = 0; elv_clear_ioq_wait_request(ioq); @@ -2764,6 +2844,22 @@ void elv_add_ioq_busy(struct elv_fq_data *efqd, struct io_queue *ioq) efqd->busy_queues++; if (elv_ioq_class_rt(ioq)) efqd->busy_rt_queues++; + +#ifdef CONFIG_DEBUG_GROUP_IOSCHED + { + char path[128]; + struct io_group *iog = ioq_to_io_group(ioq); + io_group_path(iog, path, sizeof(path)); + elv_log(efqd, "add to busy: QTt=0x%lx QTs=0x%lx " + "ioq grp=%s GTt=0x%lx GTs=0x%lx rq_queued=%d", + ioq->entity.total_service, + ioq->entity.total_sector_service, + path, + iog->entity.total_service, + iog->entity.total_sector_service, + ioq->nr_queued); + } +#endif } void elv_del_ioq_busy(struct elevator_queue *e, struct io_queue *ioq, @@ -2773,7 +2869,24 @@ void elv_del_ioq_busy(struct elevator_queue *e, struct io_queue *ioq, BUG_ON(!elv_ioq_busy(ioq)); BUG_ON(ioq->nr_queued); +#ifdef CONFIG_DEBUG_GROUP_IOSCHED + { + char path[128]; + struct io_group *iog = ioq_to_io_group(ioq); + io_group_path(iog, path, sizeof(path)); + elv_log_ioq(efqd, ioq, "del from busy: QTt=0x%lx " + "QTs=0x%lx ioq grp=%s GTt=0x%lx GTs=0x%lx " + "rq_queued=%d", + ioq->entity.total_service, + ioq->entity.total_sector_service, + path, + iog->entity.total_service, + iog->entity.total_sector_service, + ioq->nr_queued); + } +#else elv_log_ioq(efqd, ioq, "del from busy"); +#endif elv_clear_ioq_busy(ioq); BUG_ON(efqd->busy_queues == 0); efqd->busy_queues--; @@ -3000,6 +3113,14 @@ void elv_ioq_request_add(struct request_queue *q, struct request *rq) elv_ioq_update_io_thinktime(ioq); elv_ioq_update_idle_window(q->elevator, ioq, rq); +#ifdef CONFIG_DEBUG_GROUP_IOSCHED + { + char path[128]; + io_group_path(rq_iog(q, rq), path, sizeof(path)); + elv_log_ioq(efqd, ioq, "add rq: group path=%s " + "rq_queued=%d", path, ioq->nr_queued); + } +#endif if (ioq == elv_active_ioq(q->elevator)) { /* diff --git a/block/elevator-fq.h b/block/elevator-fq.h index 42e3777..db3a347 100644 --- a/block/elevator-fq.h +++ b/block/elevator-fq.h @@ -43,6 +43,8 @@ struct io_service_tree { struct rb_root active; struct rb_root idle; + int nr_active; + struct io_entity *first_idle; struct io_entity *last_idle; @@ -245,6 +247,10 @@ struct io_group { /* io group is going away */ int deleting; + +#ifdef CONFIG_DEBUG_GROUP_IOSCHED + unsigned short iocg_id; +#endif }; /** -- 1.6.0.1 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
