diff options
Diffstat (limited to 'block')
-rw-r--r-- | block/Kconfig | 3 | ||||
-rw-r--r-- | block/Makefile | 1 | ||||
-rw-r--r-- | block/bfq-cgroup.c | 4 | ||||
-rw-r--r-- | block/bfq-iosched.c | 80 | ||||
-rw-r--r-- | block/bfq-iosched.h | 26 | ||||
-rw-r--r-- | block/bfq-wf2q.c | 13 | ||||
-rw-r--r-- | block/bio-integrity.c | 12 | ||||
-rw-r--r-- | block/bio.c | 202 | ||||
-rw-r--r-- | block/blk-cgroup.c | 123 | ||||
-rw-r--r-- | block/blk-core.c | 270 | ||||
-rw-r--r-- | block/blk-integrity.c | 12 | ||||
-rw-r--r-- | block/blk-iolatency.c | 230 | ||||
-rw-r--r-- | block/blk-merge.c | 88 | ||||
-rw-r--r-- | block/blk-mq-debugfs.c | 10 | ||||
-rw-r--r-- | block/blk-mq-sched.h | 4 | ||||
-rw-r--r-- | block/blk-mq-tag.c | 69 | ||||
-rw-r--r-- | block/blk-mq.c | 9 | ||||
-rw-r--r-- | block/blk-pm.c | 216 | ||||
-rw-r--r-- | block/blk-pm.h | 69 | ||||
-rw-r--r-- | block/blk-stat.c | 1 | ||||
-rw-r--r-- | block/blk-throttle.c | 54 | ||||
-rw-r--r-- | block/blk.h | 71 | ||||
-rw-r--r-- | block/bounce.c | 4 | ||||
-rw-r--r-- | block/cfq-iosched.c | 4 | ||||
-rw-r--r-- | block/elevator.c | 22 | ||||
-rw-r--r-- | block/genhd.c | 19 | ||||
-rw-r--r-- | block/kyber-iosched.c | 547 |
27 files changed, 1368 insertions, 795 deletions
diff --git a/block/Kconfig b/block/Kconfig index 1f2469a0123c..85263e7bded6 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -228,4 +228,7 @@ config BLK_MQ_RDMA depends on BLOCK && INFINIBAND default y +config BLK_PM + def_bool BLOCK && PM + source block/Kconfig.iosched diff --git a/block/Makefile b/block/Makefile index 572b33f32c07..27eac600474f 100644 --- a/block/Makefile +++ b/block/Makefile @@ -37,3 +37,4 @@ obj-$(CONFIG_BLK_WBT) += blk-wbt.o obj-$(CONFIG_BLK_DEBUG_FS) += blk-mq-debugfs.o obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o obj-$(CONFIG_BLK_SED_OPAL) += sed-opal.o +obj-$(CONFIG_BLK_PM) += blk-pm.o diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 9fe5952d117d..d9a7916ff0ab 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -642,7 +642,7 @@ void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) uint64_t serial_nr; rcu_read_lock(); - serial_nr = bio_blkcg(bio)->css.serial_nr; + serial_nr = __bio_blkcg(bio)->css.serial_nr; /* * Check whether blkcg has changed. The condition may trigger @@ -651,7 +651,7 @@ void bfq_bic_update_cgroup(struct bfq_io_cq *bic, struct bio *bio) if (unlikely(!bfqd) || likely(bic->blkcg_serial_nr == serial_nr)) goto out; - bfqg = __bfq_bic_change_cgroup(bfqd, bic, bio_blkcg(bio)); + bfqg = __bfq_bic_change_cgroup(bfqd, bic, __bio_blkcg(bio)); /* * Update blkg_path for bfq_log_* functions. We cache this * path, and update it here, for the following diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 653100fb719e..1a1b80dfd69d 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -3182,6 +3182,13 @@ static unsigned long bfq_bfqq_softrt_next_start(struct bfq_data *bfqd, jiffies + nsecs_to_jiffies(bfqq->bfqd->bfq_slice_idle) + 4); } +static bool bfq_bfqq_injectable(struct bfq_queue *bfqq) +{ + return BFQQ_SEEKY(bfqq) && bfqq->wr_coeff == 1 && + blk_queue_nonrot(bfqq->bfqd->queue) && + bfqq->bfqd->hw_tag; +} + /** * bfq_bfqq_expire - expire a queue. * @bfqd: device owning the queue. @@ -3291,6 +3298,8 @@ void bfq_bfqq_expire(struct bfq_data *bfqd, if (ref == 1) /* bfqq is gone, no more actions on it */ return; + bfqq->injected_service = 0; + /* mark bfqq as waiting a request only if a bic still points to it */ if (!bfq_bfqq_busy(bfqq) && reason != BFQQE_BUDGET_TIMEOUT && @@ -3571,7 +3580,12 @@ static bool bfq_better_to_idle(struct bfq_queue *bfqq) * whether bfqq is being weight-raised, because * bfq_symmetric_scenario() does not take into account also * weight-raised queues (see comments on - * bfq_weights_tree_add()). + * bfq_weights_tree_add()). In particular, if bfqq is being + * weight-raised, it is important to idle only if there are + * other, non-weight-raised queues that may steal throughput + * to bfqq. Actually, we should be even more precise, and + * differentiate between interactive weight raising and + * soft real-time weight raising. * * As a side note, it is worth considering that the above * device-idling countermeasures may however fail in the @@ -3583,7 +3597,8 @@ static bool bfq_better_to_idle(struct bfq_queue *bfqq) * to let requests be served in the desired order until all * the requests already queued in the device have been served. */ - asymmetric_scenario = bfqq->wr_coeff > 1 || + asymmetric_scenario = (bfqq->wr_coeff > 1 && + bfqd->wr_busy_queues < bfqd->busy_queues) || !bfq_symmetric_scenario(bfqd); /* @@ -3629,6 +3644,30 @@ static bool bfq_bfqq_must_idle(struct bfq_queue *bfqq) return RB_EMPTY_ROOT(&bfqq->sort_list) && bfq_better_to_idle(bfqq); } +static struct bfq_queue *bfq_choose_bfqq_for_injection(struct bfq_data *bfqd) +{ + struct bfq_queue *bfqq; + + /* + * A linear search; but, with a high probability, very few + * steps are needed to find a candidate queue, i.e., a queue + * with enough budget left for its next request. In fact: + * - BFQ dynamically updates the budget of every queue so as + * to accommodate the expected backlog of the queue; + * - if a queue gets all its requests dispatched as injected + * service, then the queue is removed from the active list + * (and re-added only if it gets new requests, but with + * enough budget for its new backlog). + */ + list_for_each_entry(bfqq, &bfqd->active_list, bfqq_list) + if (!RB_EMPTY_ROOT(&bfqq->sort_list) && + bfq_serv_to_charge(bfqq->next_rq, bfqq) <= + bfq_bfqq_budget_left(bfqq)) + return bfqq; + + return NULL; +} + /* * Select a queue for service. If we have a current queue in service, * check whether to continue servicing it, or retrieve and set a new one. @@ -3710,10 +3749,19 @@ check_queue: * No requests pending. However, if the in-service queue is idling * for a new request, or has requests waiting for a completion and * may idle after their completion, then keep it anyway. + * + * Yet, to boost throughput, inject service from other queues if + * possible. */ if (bfq_bfqq_wait_request(bfqq) || (bfqq->dispatched != 0 && bfq_better_to_idle(bfqq))) { - bfqq = NULL; + if (bfq_bfqq_injectable(bfqq) && + bfqq->injected_service * bfqq->inject_coeff < + bfqq->entity.service * 10) + bfqq = bfq_choose_bfqq_for_injection(bfqd); + else + bfqq = NULL; + goto keep_queue; } @@ -3803,6 +3851,14 @@ static struct request *bfq_dispatch_rq_from_bfqq(struct bfq_data *bfqd, bfq_dispatch_remove(bfqd->queue, rq); + if (bfqq != bfqd->in_service_queue) { + if (likely(bfqd->in_service_queue)) + bfqd->in_service_queue->injected_service += + bfq_serv_to_charge(rq, bfqq); + + goto return_rq; + } + /* * If weight raising has to terminate for bfqq, then next * function causes an immediate update of bfqq's weight, @@ -3821,13 +3877,12 @@ static struct request *bfq_dispatch_rq_from_bfqq(struct bfq_data *bfqd, * belongs to CLASS_IDLE and other queues are waiting for * service. */ - if (bfqd->busy_queues > 1 && bfq_class_idle(bfqq)) - goto expire; - - return rq; + if (!(bfqd->busy_queues > 1 && bfq_class_idle(bfqq))) + goto return_rq; -expire: bfq_bfqq_expire(bfqd, bfqq, false, BFQQE_BUDGET_EXHAUSTED); + +return_rq: return rq; } @@ -4232,6 +4287,13 @@ static void bfq_init_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq, bfq_mark_bfqq_has_short_ttime(bfqq); bfq_mark_bfqq_sync(bfqq); bfq_mark_bfqq_just_created(bfqq); + /* + * Aggressively inject a lot of service: up to 90%. + * This coefficient remains constant during bfqq life, + * but this behavior might be changed, after enough + * testing and tuning. + */ + bfqq->inject_coeff = 1; } else bfq_clear_bfqq_sync(bfqq); @@ -4297,7 +4359,7 @@ static struct bfq_queue *bfq_get_queue(struct bfq_data *bfqd, rcu_read_lock(); - bfqg = bfq_find_set_group(bfqd, bio_blkcg(bio)); + bfqg = bfq_find_set_group(bfqd, __bio_blkcg(bio)); if (!bfqg) { bfqq = &bfqd->oom_bfqq; goto out; diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index a8a2e5aca4d4..37d627afdc2e 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -351,6 +351,32 @@ struct bfq_queue { unsigned long split_time; /* time of last split */ unsigned long first_IO_time; /* time of first I/O for this queue */ + + /* max service rate measured so far */ + u32 max_service_rate; + /* + * Ratio between the service received by bfqq while it is in + * service, and the cumulative service (of requests of other + * queues) that may be injected while bfqq is empty but still + * in service. To increase precision, the coefficient is + * measured in tenths of unit. Here are some example of (1) + * ratios, (2) resulting percentages of service injected + * w.r.t. to the total service dispatched while bfqq is in + * service, and (3) corresponding values of the coefficient: + * 1 (50%) -> 10 + * 2 (33%) -> 20 + * 10 (9%) -> 100 + * 9.9 (9%) -> 99 + * 1.5 (40%) -> 15 + * 0.5 (66%) -> 5 + * 0.1 (90%) -> 1 + * + * So, if the coefficient is lower than 10, then + * injected service is more than bfqq service. + */ + unsigned int inject_coeff; + /* amount of service injected in current service slot */ + unsigned int injected_service; }; /** diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c index ae52bff43ce4..ff7c2d470bb8 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -1181,10 +1181,17 @@ bool __bfq_deactivate_entity(struct bfq_entity *entity, bool ins_into_idle_tree) st = bfq_entity_service_tree(entity); is_in_service = entity == sd->in_service_entity; - if (is_in_service) { - bfq_calc_finish(entity, entity->service); + bfq_calc_finish(entity, entity->service); + + if (is_in_service) sd->in_service_entity = NULL; - } + else + /* + * Non in-service entity: nobody will take care of + * resetting its service counter on expiration. Do it + * now. + */ + entity->service = 0; if (entity->tree == &st->active) bfq_active_extract(st, entity); diff --git a/block/bio-integrity.c b/block/bio-integrity.c index 67b5fb861a51..290af497997b 100644 --- a/block/bio-integrity.c +++ b/block/bio-integrity.c @@ -306,6 +306,8 @@ bool bio_integrity_prep(struct bio *bio) if (bio_data_dir(bio) == WRITE) { bio_integrity_process(bio, &bio->bi_iter, bi->profile->generate_fn); + } else { + bip->bio_iter = bio->bi_iter; } return true; @@ -331,20 +333,14 @@ static void bio_integrity_verify_fn(struct work_struct *work) container_of(work, struct bio_integrity_payload, bip_work); struct bio *bio = bip->bip_bio; struct blk_integrity *bi = blk_get_integrity(bio->bi_disk); - struct bvec_iter iter = bio->bi_iter; /* * At the moment verify is called bio's iterator was advanced * during split and completion, we need to rewind iterator to * it's original position. */ - if (bio_rewind_iter(bio, &iter, iter.bi_done)) { - bio->bi_status = bio_integrity_process(bio, &iter, - bi->profile->verify_fn); - } else { - bio->bi_status = BLK_STS_IOERR; - } - + bio->bi_status = bio_integrity_process(bio, &bip->bio_iter, + bi->profile->verify_fn); bio_integrity_free(bio); bio_endio(bio); } diff --git a/block/bio.c b/block/bio.c index 0093bed81c0e..17a8b0aa7050 100644 --- a/block/bio.c +++ b/block/bio.c @@ -609,7 +609,9 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src) bio->bi_iter = bio_src->bi_iter; bio->bi_io_vec = bio_src->bi_io_vec; - bio_clone_blkcg_association(bio, bio_src); + bio_clone_blkg_association(bio, bio_src); + + blkcg_bio_issue_init(bio); } EXPORT_SYMBOL(__bio_clone_fast); @@ -729,7 +731,7 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page } /* If we may be able to merge these biovecs, force a recount */ - if (bio->bi_vcnt > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) + if (bio->bi_vcnt > 1 && biovec_phys_mergeable(q, bvec - 1, bvec)) bio_clear_flag(bio, BIO_SEG_VALID); done: @@ -827,6 +829,8 @@ int bio_add_page(struct bio *bio, struct page *page, } EXPORT_SYMBOL(bio_add_page); +#define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *)) + /** * __bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio * @bio: bio to add pages to @@ -839,38 +843,35 @@ EXPORT_SYMBOL(bio_add_page); */ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) { - unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt, idx; + unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt; + unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt; struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt; struct page **pages = (struct page **)bv; + ssize_t size, left; + unsigned len, i; size_t offset; - ssize_t size; + + /* + * Move page array up in the allocated memory for the bio vecs as far as + * possible so that we can start filling biovecs from the beginning + * without overwriting the temporary page array. + */ + BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2); + pages += entries_left * (PAGE_PTRS_PER_BVEC - 1); size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset); if (unlikely(size <= 0)) return size ? size : -EFAULT; - idx = nr_pages = (size + offset + PAGE_SIZE - 1) / PAGE_SIZE; - /* - * Deep magic below: We need to walk the pinned pages backwards - * because we are abusing the space allocated for the bio_vecs - * for the page array. Because the bio_vecs are larger than the - * page pointers by definition this will always work. But it also - * means we can't use bio_add_page, so any changes to it's semantics - * need to be reflected here as well. - */ - bio->bi_iter.bi_size += size; - bio->bi_vcnt += nr_pages; + for (left = size, i = 0; left > 0; left -= len, i++) { + struct page *page = pages[i]; - while (idx--) { - bv[idx].bv_page = pages[idx]; - bv[idx].bv_len = PAGE_SIZE; - bv[idx].bv_offset = 0; + len = min_t(size_t, PAGE_SIZE - offset, left); + if (WARN_ON_ONCE(bio_add_page(bio, page, len, offset) != len)) + return -EINVAL; + offset = 0; } - bv[0].bv_offset += offset; - bv[0].bv_len -= offset; - bv[nr_pages - 1].bv_len -= nr_pages * PAGE_SIZE - offset - size; - iov_iter_advance(iter, size); return 0; } @@ -1807,7 +1808,6 @@ struct bio *bio_split(struct bio *bio, int sectors, bio_integrity_trim(split); bio_advance(bio, split->bi_iter.bi_size); - bio->bi_iter.bi_done = 0; if (bio_flagged(bio, BIO_TRACE_COMPLETION)) bio_set_flag(split, BIO_TRACE_COMPLETION); @@ -1956,69 +1956,131 @@ EXPORT_SYMBOL(bioset_init_from_src); #ifdef CONFIG_BLK_CGROUP -#ifdef CONFIG_MEMCG /** - * bio_associate_blkcg_from_page - associate a bio with the page's blkcg + * bio_associate_blkg - associate a bio with the a blkg * @bio: target bio - * @page: the page to lookup the blkcg from + * @blkg: the blkg to associate + * + * This tries to associate @bio with the specified blkg. Association failure + * is handled by walking up the blkg tree. Therefore, the blkg associated can + * be anything between @blkg and the root_blkg. This situation only happens + * when a cgroup is dying and then the remaining bios will spill to the closest + * alive blkg. * - * Associate @bio with the blkcg from @page's owning memcg. This works like - * every other associate function wrt references. + * A reference will be taken on the @blkg and will be released when @bio is + * freed. */ -int bio_associate_blkcg_from_page(struct bio *bio, struct page *page) +int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) { - struct cgroup_subsys_state *blkcg_css; - - if (unlikely(bio->bi_css)) + if (unlikely(bio->bi_blkg)) return -EBUSY; - if (!page->mem_cgroup) - return 0; - blkcg_css = cgroup_get_e_css(page->mem_cgroup->css.cgroup, - &io_cgrp_subsys); - bio->bi_css = blkcg_css; + bio->bi_blkg = blkg_tryget_closest(blkg); return 0; } -#endif /* CONFIG_MEMCG */ /** - * bio_associate_blkcg - associate a bio with the specified blkcg - * @bio: target bio - * @blkcg_css: css of the blkcg to associate + * __bio_associate_blkg_from_css - internal blkg association function * - * Associate @bio with the blkcg specified by @blkcg_css. Block layer will - * treat @bio as if it were issued by a task which belongs to the blkcg. + * This in the core association function that all association paths rely on. + * A blkg reference is taken which is released upon freeing of the bio. + */ +static int __bio_associate_blkg_from_css(struct bio *bio, + struct cgroup_subsys_state *css) +{ + struct request_queue *q = bio->bi_disk->queue; + struct blkcg_gq *blkg; + int ret; + + rcu_read_lock(); + + if (!css || !css->parent) + blkg = q->root_blkg; + else + blkg = blkg_lookup_create(css_to_blkcg(css), q); + + ret = bio_associate_blkg(bio, blkg); + + rcu_read_unlock(); + return ret; +} + +/** + * bio_associate_blkg_from_css - associate a bio with a specified css + * @bio: target bio + * @css: target css * - * This function takes an extra reference of @blkcg_css which will be put - * when @bio is released. The caller must own @bio and is responsible for - * synchronizing calls to this function. + * Associate @bio with the blkg found by combining the css's blkg and the + * request_queue of the @bio. This falls back to the queue's root_blkg if + * the association fails with the css. */ -int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css) +int bio_associate_blkg_from_css(struct bio *bio, + struct cgroup_subsys_state *css) { - if (unlikely(bio->bi_css)) + if (unlikely(bio->bi_blkg)) return -EBUSY; - css_get(blkcg_css); - bio->bi_css = blkcg_css; - return 0; + return __bio_associate_blkg_from_css(bio, css); } -EXPORT_SYMBOL_GPL(bio_associate_blkcg); +EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css); +#ifdef CONFIG_MEMCG /** - * bio_associate_blkg - associate a bio with the specified blkg + * bio_associate_blkg_from_page - associate a bio with the page's blkg * @bio: target bio - * @blkg: the blkg to associate + * @page: the page to lookup the blkcg from * - * Associate @bio with the blkg specified by @blkg. This is the queue specific - * blkcg information associated with the @bio, a reference will be taken on the - * @blkg and will be freed when the bio is freed. + * Associate @bio with the blkg from @page's owning memcg and the respective + * request_queue. If cgroup_e_css returns NULL, fall back to the queue's + * root_blkg. + * + * Note: this must be called after bio has an associated device. */ -int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg) +int bio_associate_blkg_from_page(struct bio *bio, struct page *page) { + struct cgroup_subsys_state *css; + int ret; + if (unlikely(bio->bi_blkg)) return -EBUSY; - if (!blkg_try_get(blkg)) - return -ENODEV; - bio->bi_blkg = blkg; - return 0; + if (!page->mem_cgroup) + return 0; + + rcu_read_lock(); + + css = cgroup_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys); + + ret = __bio_associate_blkg_from_css(bio, css); + + rcu_read_unlock(); + return ret; +} +#endif /* CONFIG_MEMCG */ + +/** + * bio_associate_create_blkg - associate a bio with a blkg from q + * @q: request_queue where bio is going + * @bio: target bio + * + * Associate @bio with the blkg found from the bio's css and the request_queue. + * If one is not found, bio_lookup_blkg creates the blkg. This falls back to + * the queue's root_blkg if association fails. + */ +int bio_associate_create_blkg(struct request_queue *q, struct bio *bio) +{ + struct cgroup_subsys_state *css; + int ret = 0; + + /* someone has already associated this bio with a blkg */ + if (bio->bi_blkg) + return ret; + + rcu_read_lock(); + + css = blkcg_css(); + + ret = __bio_associate_blkg_from_css(bio, css); + + rcu_read_unlock(); + return ret; } /** @@ -2031,10 +2093,6 @@ void bio_disassociate_task(struct bio *bio) put_io_context(bio->bi_ioc); bio->bi_ioc = NULL; } - if (bio->bi_css) { - css_put(bio->bi_css); - bio->bi_css = NULL; - } if (bio->bi_blkg) { blkg_put(bio->bi_blkg); bio->bi_blkg = NULL; @@ -2042,16 +2100,16 @@ void bio_disassociate_task(struct bio *bio) } /** - * bio_clone_blkcg_association - clone blkcg association from src to dst bio + * bio_clone_blkg_association - clone blkg association from src to dst bio * @dst: destination bio * @src: source bio */ -void bio_clone_blkcg_association(struct bio *dst, struct bio *src) +void bio_clone_blkg_association(struct bio *dst, struct bio *src) { - if (src->bi_css) - WARN_ON(bio_associate_blkcg(dst, src->bi_css)); + if (src->bi_blkg) + bio_associate_blkg(dst, src->bi_blkg); } -EXPORT_SYMBOL_GPL(bio_clone_blkcg_association); +EXPORT_SYMBOL_GPL(bio_clone_blkg_association); #endif /* CONFIG_BLK_CGROUP */ static void __init biovec_init_slabs(void) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index c630e02836a8..992da5592c6e 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -84,6 +84,37 @@ static void blkg_free(struct blkcg_gq *blkg) kfree(blkg); } +static void __blkg_release(struct rcu_head *rcu) +{ + struct blkcg_gq *blkg = container_of(rcu, struct blkcg_gq, rcu_head); + + percpu_ref_exit(&blkg->refcnt); + + /* release the blkcg and parent blkg refs this blkg has been holding */ + css_put(&blkg->blkcg->css); + if (blkg->parent) + blkg_put(blkg->parent); + + wb_congested_put(blkg->wb_congested); + + blkg_free(blkg); +} + +/* + * A group is RCU protected, but having an rcu lock does not mean that one + * can access all the fields of blkg and assume these are valid. For + * example, don't try to follow throtl_data and request queue links. + * + * Having a reference to blkg under an rcu allows accesses to only values + * local to groups like group stats and group rate limits. + */ +static void blkg_release(struct percpu_ref *ref) +{ + struct blkcg_gq *blkg = container_of(ref, struct blkcg_gq, refcnt); + + call_rcu(&blkg->rcu_head, __blkg_release); +} + /** * blkg_alloc - allocate a blkg * @blkcg: block cgroup the new blkg is associated with @@ -110,7 +141,6 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q, blkg->q = q; INIT_LIST_HEAD(&blkg->q_node); blkg->blkcg = blkcg; - atomic_set(&blkg->refcnt, 1); /* root blkg uses @q->root_rl, init rl only for !root blkgs */ if (blkcg != &blkcg_root) { @@ -217,6 +247,11 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, blkg_get(blkg->parent); } + ret = percpu_ref_init(&blkg->refcnt, blkg_release, 0, + GFP_NOWAIT | __GFP_NOWARN); + if (ret) + goto err_cancel_ref; + /* invoke per-policy init */ for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkcg_policy *pol = blkcg_policy[i]; @@ -249,6 +284,8 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, blkg_put(blkg); return ERR_PTR(ret); +err_cancel_ref: + percpu_ref_exit(&blkg->refcnt); err_put_congested: wb_congested_put(wb_congested); err_put_css: @@ -259,7 +296,7 @@ err_free_blkg: } /** - * blkg_lookup_create - lookup blkg, try to create one if not there + * __blkg_lookup_create - lookup blkg, try to create one if not there * @blkcg: blkcg of interest * @q: request_queue of interest * @@ -268,12 +305,11 @@ err_free_blkg: * that all non-root blkg's have access to the parent blkg. This function * should be called under RCU read lock and @q->queue_lock. * - * Returns pointer to the looked up or created blkg on success, ERR_PTR() - * value on error. If @q is dead, returns ERR_PTR(-EINVAL). If @q is not - * dead and bypassing, returns ERR_PTR(-EBUSY). + * Returns the blkg or the closest blkg if blkg_create fails as it walks + * down from root. */ -struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, - struct request_queue *q) +struct blkcg_gq *__blkg_lookup_create(struct blkcg *blkcg, + struct request_queue *q) { struct blkcg_gq *blkg; @@ -285,7 +321,7 @@ struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, * we shouldn't allow anything to go through for a bypassing queue. */ if (unlikely(blk_queue_bypass(q))) - return ERR_PTR(blk_queue_dying(q) ? -ENODEV : -EBUSY); + return q->root_blkg; blkg = __blkg_lookup(blkcg, q, true); if (blkg) @@ -293,23 +329,58 @@ struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, /* * Create blkgs walking down from blkcg_root to @blkcg, so that all - * non-root blkgs have access to their parents. + * non-root blkgs have access to their parents. Returns the closest + * blkg to the intended blkg should blkg_create() fail. */ while (true) { struct blkcg *pos = blkcg; struct blkcg *parent = blkcg_parent(blkcg); - - while (parent && !__blkg_lookup(parent, q, false)) { + struct blkcg_gq *ret_blkg = q->root_blkg; + + while (parent) { + blkg = __blkg_lookup(parent, q, false); + if (blkg) { + /* remember closest blkg */ + ret_blkg = blkg; + break; + } pos = parent; parent = blkcg_parent(parent); } blkg = blkg_create(pos, q, NULL); - if (pos == blkcg || IS_ERR(blkg)) + if (IS_ERR(blkg)) + return ret_blkg; + if (pos == blkcg) return blkg; } } +/** + * blkg_lookup_create - find or create a blkg + * @blkcg: target block cgroup + * @q: target request_queue + * + * This looks up or creates the blkg representing the unique pair + * of the blkcg and the request_queue. + */ +struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, + struct request_queue *q) +{ + struct blkcg_gq *blkg = blkg_lookup(blkcg, q); + unsigned long flags; + + if (unlikely(!blkg)) { + spin_lock_irqsave(q->queue_lock, flags); + + blkg = __blkg_lookup_create(blkcg, q); + + spin_unlock_irqrestore(q->queue_lock, flags); + } + + return blkg; +} + static void blkg_destroy(struct blkcg_gq *blkg) { struct blkcg *blkcg = blkg->blkcg; @@ -353,7 +424,7 @@ static void blkg_destroy(struct blkcg_gq *blkg) * Put the reference taken at the time of creation so that when all * queues are gone, group can be destroyed. */ - blkg_put(blkg); + percpu_ref_kill(&blkg->refcnt); } /** @@ -381,29 +452,6 @@ static void blkg_destroy_all(struct request_queue *q) } /* - * A group is RCU protected, but having an rcu lock does not mean that one - * can access all the fields of blkg and assume these are valid. For - * example, don't try to follow throtl_data and request queue links. - * - * Having a reference to blkg under an rcu allows accesses to only values - * local to groups like group stats and group rate limits. - */ -void __blkg_release_rcu(struct rcu_head *rcu_head) -{ - struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head); - - /* release the blkcg and parent blkg refs this blkg has been holding */ - css_put(&blkg->blkcg->css); - if (blkg->parent) - blkg_put(blkg->parent); - - wb_congested_put(blkg->wb_congested); - - blkg_free(blkg); -} -EXPORT_SYMBOL_GPL(__blkg_release_rcu); - -/* * The next function used by blk_queue_for_each_rl(). It's a bit tricky * because the root blkg uses @q->root_rl instead of its own rl. */ @@ -1748,8 +1796,7 @@ void blkcg_maybe_throttle_current(void) blkg = blkg_lookup(blkcg, q); if (!blkg) goto out; - blkg = blkg_try_get(blkg); - if (!blkg) + if (!blkg_tryget(blkg)) goto out; rcu_read_unlock(); diff --git a/block/blk-core.c b/block/blk-core.c index cff0a60ee200..f12d2b65e5a5 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -42,6 +42,7 @@ #include "blk.h" #include "blk-mq.h" #include "blk-mq-sched.h" +#include "blk-pm.h" #include "blk-rq-qos.h" #ifdef CONFIG_DEBUG_FS @@ -421,24 +422,25 @@ void blk_sync_queue(struct request_queue *q) EXPORT_SYMBOL(blk_sync_queue); /** - * blk_set_preempt_only - set QUEUE_FLAG_PREEMPT_ONLY + * blk_set_pm_only - increment pm_only counter * @q: request queue pointer - * - * Returns the previous value of the PREEMPT_ONLY flag - 0 if the flag was not - * set and 1 if the flag was already set. */ -int blk_set_preempt_only(struct request_queue *q) +void blk_set_pm_only(struct request_queue *q) { - return blk_queue_flag_test_and_set(QUEUE_FLAG_PREEMPT_ONLY, q); + atomic_inc(&q->pm_only); } -EXPORT_SYMBOL_GPL(blk_set_preempt_only); +EXPORT_SYMBOL_GPL(blk_set_pm_only); -void blk_clear_preempt_only(struct request_queue *q) +void blk_clear_pm_only(struct request_queue *q) { - blk_queue_flag_clear(QUEUE_FLAG_PREEMPT_ONLY, q); - wake_up_all(&q->mq_freeze_wq); + int pm_only; + + pm_only = atomic_dec_return(&q->pm_only); + WARN_ON_ONCE(pm_only < 0); + if (pm_only == 0) + wake_up_all(&q->mq_freeze_wq); } -EXPORT_SYMBOL_GPL(blk_clear_preempt_only); +EXPORT_SYMBOL_GPL(blk_clear_pm_only); /** * __blk_run_queue_uncond - run a queue whether or not it has been stopped @@ -917,7 +919,7 @@ EXPORT_SYMBOL(blk_alloc_queue); */ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) { - const bool preempt = flags & BLK_MQ_REQ_PREEMPT; + const bool pm = flags & BLK_MQ_REQ_PREEMPT; while (true) { bool success = false; @@ -925,11 +927,11 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) rcu_read_lock(); if (percpu_ref_tryget_live(&q->q_usage_counter)) { /* - * The code that sets the PREEMPT_ONLY flag is - * responsible for ensuring that that flag is globally - * visible before the queue is unfrozen. + * The code that increments the pm_only counter is + * responsible for ensuring that that counter is + * globally visible before the queue is unfrozen. */ - if (preempt || !blk_queue_preempt_only(q)) { + if (pm || !blk_queue_pm_only(q)) { success = true; } else { percpu_ref_put(&q->q_usage_counter); @@ -954,7 +956,8 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) wait_event(q->mq_freeze_wq, (atomic_read(&q->mq_freeze_depth) == 0 && - (preempt || !blk_queue_preempt_only(q))) || + (pm || (blk_pm_request_resume(q), + !blk_queue_pm_only(q)))) || blk_queue_dying(q)); if (blk_queue_dying(q)) return -ENODEV; @@ -1726,16 +1729,6 @@ void part_round_stats(struct request_queue *q, int cpu, struct hd_struct *part) } EXPORT_SYMBOL_GPL(part_round_stats); -#ifdef CONFIG_PM -static void blk_pm_put_request(struct request *rq) -{ - if (rq->q->dev && !(rq->rq_flags & RQF_PM) && !--rq->q->nr_pending) - pm_runtime_mark_last_busy(rq->q->dev); -} -#else -static inline void blk_pm_put_request(struct request *rq) {} -#endif - void __blk_put_request(struct request_queue *q, struct request *req) { req_flags_t rq_flags = req->rq_flags; @@ -1752,6 +1745,7 @@ void __blk_put_request(struct request_queue *q, struct request *req) blk_req_zone_write_unlock(req); blk_pm_put_request(req); + blk_pm_mark_last_busy(req); elv_completed_request(q, req); @@ -2750,30 +2744,6 @@ void blk_account_io_done(struct request *req, u64 now) } } -#ifdef CONFIG_PM -/* - * Don't process normal requests when queue is suspended - * or in the process of suspending/resuming - */ -static bool blk_pm_allow_request(struct request *rq) -{ - switch (rq->q->rpm_status) { - case RPM_RESUMING: - case RPM_SUSPENDING: - return rq->rq_flags & RQF_PM; - case RPM_SUSPENDED: - return false; - default: - return true; - } -} -#else -static bool blk_pm_allow_request(struct request *rq) -{ - return true; -} -#endif - void blk_account_io_start(struct request *rq, bool new_io) { struct hd_struct *part; @@ -2819,11 +2789,14 @@ static struct request *elv_next_request(struct request_queue *q) while (1) { list_for_each_entry(rq, &q->queue_head, queuelist) { - if (blk_pm_allow_request(rq)) - return rq; - - if (rq->rq_flags & RQF_SOFTBARRIER) - break; +#ifdef CONFIG_PM + /* + * If a request gets queued in state RPM_SUSPENDED + * then that's a kernel bug. + */ + WARN_ON_ONCE(q->rpm_status == RPM_SUSPENDED); +#endif + return rq; } /* @@ -3755,191 +3728,6 @@ void blk_finish_plug(struct blk_plug *plug) } EXPORT_SYMBOL(blk_finish_plug); -#ifdef CONFIG_PM -/** - * blk_pm_runtime_init - Block layer runtime PM initialization routine - * @q: the queue of the device - * @dev: the device the queue belongs to - * - * Description: - * Initialize runtime-PM-related fields for @q and start auto suspend for - * @dev. Drivers that want to take advantage of request-based runtime PM - * should call this function after @dev has been initialized, and its - * request queue @q has been allocated, and runtime PM for it can not happen - * yet(either due to disabled/forbidden or its usage_count > 0). In most - * cases, driver should call this function before any I/O has taken place. - * - * This function takes care of setting up using auto suspend for the device, - * the autosuspend delay is set to -1 to make runtime suspend impossible - * until an updated value is either set by user or by driver. Drivers do - * not need to touch other autosuspend settings. - * - * The block layer runtime PM is request based, so only works for drivers - * that use request as their IO unit instead of those directly use bio's. - */ -void blk_pm_runtime_init(struct request_queue *q, struct device *dev) -{ - /* Don't enable runtime PM for blk-mq until it is ready */ - if (q->mq_ops) { - pm_runtime_disable(dev); - return; - } - - q->dev = dev; - q->rpm_status = RPM_ACTIVE; - pm_runtime_set_autosuspend_delay(q->dev, -1); - pm_runtime_use_autosuspend(q->dev); -} -EXPORT_SYMBOL(blk_pm_runtime_init); - -/** - * blk_pre_runtime_suspend - Pre runtime suspend check - * @q: the queue of the device - * - * Description: - * This function will check if runtime suspend is allowed for the device - * by examining if there are any requests pending in the queue. If there - * are requests pending, the device can not be runtime suspended; otherwise, - * the queue's status will be updated to SUSPENDING and the driver can - * proceed to suspend the device. - * - * For the not allowed case, we mark last busy for the device so that - * runtime PM core will try to autosuspend it some time later. - * - * This function should be called near the start of the device's - * runtime_suspend callback. - * - * Return: - * 0 - OK to runtime suspend the device - * -EBUSY - Device should not be runtime suspended - */ -int blk_pre_runtime_suspend(struct request_queue *q) -{ - int ret = 0; - - if (!q->dev) - return ret; - - spin_lock_irq(q->queue_lock); - if (q->nr_pending) { - ret = -EBUSY; - pm_runtime_mark_last_busy(q->dev); - } else { - q->rpm_status = RPM_SUSPENDING; - } - spin_unlock_irq(q->queue_lock); - return ret; -} -EXPORT_SYMBOL(blk_pre_runtime_suspend); - -/** - * blk_post_runtime_suspend - Post runtime suspend processing - * @q: the queue of the device - * @err: return value of the device's runtime_suspend function - * - * Description: - * Update the queue's runtime status according to the return value of the - * device's runtime suspend function and mark last busy for the device so - * that PM core will try to auto suspend the device at a later time. - * - * This function should be called near the end of the device's - * runtime_suspend callback. - */ -void blk_post_runtime_suspend(struct request_queue *q, int err) -{ - if (!q->dev) - return; - - spin_lock_irq(q->queue_lock); - if (!err) { - q->rpm_status = RPM_SUSPENDED; - } else { - q->rpm_status = RPM_ACTIVE; - pm_runtime_mark_last_busy(q->dev); - } - spin_unlock_irq(q->queue_lock); -} -EXPORT_SYMBOL(blk_post_runtime_suspend); - -/** - * blk_pre_runtime_resume - Pre runtime resume processing - * @q: the queue of the device - * - * Description: - * Update the queue's runtime status to RESUMING in preparation for the - * runtime resume of the device. - * - * This function should be called near the start of the device's - * runtime_resume callback. - */ -void blk_pre_runtime_resume(struct request_queue *q) -{ - if (!q->dev) - return; - - spin_lock_irq(q->queue_lock); - q->rpm_status = RPM_RESUMING; - spin_unlock_irq(q->queue_lock); -} -EXPORT_SYMBOL(blk_pre_runtime_resume); - -/** - * blk_post_runtime_resume - Post runtime resume processing - * @q: the queue of the device - * @err: return value of the device's runtime_resume function - * - * Description: - * Update the queue's runtime status according to the return value of the - * device's runtime_resume function. If it is successfully resumed, process - * the requests that are queued into the device's queue when it is resuming - * and then mark last busy and initiate autosuspend for it. - * - * This function should be called near the end of the device's - * runtime_resume callback. - */ -void blk_post_runtime_resume(struct request_queue *q, int err) -{ - if (!q->dev) - return; - - spin_lock_irq(q->queue_lock); - if (!err) { - q->rpm_status = RPM_ACTIVE; - __blk_run_queue(q); - pm_runtime_mark_last_busy(q->dev); - pm_request_autosuspend(q->dev); - } else { - q->rpm_status = RPM_SUSPENDED; - } - spin_unlock_irq(q->queue_lock); -} -EXPORT_SYMBOL(blk_post_runtime_resume); - -/** - * blk_set_runtime_active - Force runtime status of the queue to be active - * @q: the queue of the device - * - * If the device is left runtime suspended during system suspend the resume - * hook typically resumes the device and corrects runtime status - * accordingly. However, that does not affect the queue runtime PM status - * which is still "suspended". This prevents processing requests from the - * queue. - * - * This function can be used in driver's resume hook to correct queue - * runtime PM status and re-enable peeking requests from the queue. It - * should be called before first request is added to the queue. - */ -void blk_set_runtime_active(struct request_queue *q) -{ - spin_lock_irq(q->queue_lock); - q->rpm_status = RPM_ACTIVE; - pm_runtime_mark_last_busy(q->dev); - pm_request_autosuspend(q->dev); - spin_unlock_irq(q->queue_lock); -} -EXPORT_SYMBOL(blk_set_runtime_active); -#endif - int __init blk_dev_init(void) { BUILD_BUG_ON(REQ_OP_LAST >= (1 << REQ_OP_BITS)); diff --git a/block/blk-integrity.c b/block/blk-integrity.c index 6121611e1316..d1ab089e0919 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -49,12 +49,8 @@ int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio) bio_for_each_integrity_vec(iv, bio, iter) { if (prev) { - if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv)) + if (!biovec_phys_mergeable(q, &ivprv, &iv)) goto new_segment; - - if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv)) - goto new_segment; - if (seg_size + iv.bv_len > queue_max_segment_size(q)) goto new_segment; @@ -95,12 +91,8 @@ int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio, bio_for_each_integrity_vec(iv, bio, iter) { if (prev) { - if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv)) + if (!biovec_phys_mergeable(q, &ivprv, &iv)) goto new_segment; - - if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv)) - goto new_segment; - if (sg->length + iv.bv_len > queue_max_segment_size(q)) goto new_segment; diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index 19923f8a029d..35c48d7b8f78 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -115,9 +115,22 @@ struct child_latency_info { atomic_t scale_cookie; }; +struct percentile_stats { + u64 total; + u64 missed; +}; + +struct latency_stat { + union { + struct percentile_stats ps; + struct blk_rq_stat rqs; + }; +}; + struct iolatency_grp { struct blkg_policy_data pd; - struct blk_rq_stat __percpu *stats; + struct latency_stat __percpu *stats; + struct latency_stat cur_stat; struct blk_iolatency *blkiolat; struct rq_depth rq_depth; struct rq_wait rq_wait; @@ -132,6 +145,7 @@ struct iolatency_grp { /* Our current number of IO's for the last summation. */ u64 nr_samples; + bool ssd; struct child_latency_info child_lat; }; @@ -172,6 +186,80 @@ static inline struct blkcg_gq *lat_to_blkg(struct iolatency_grp *iolat) return pd_to_blkg(&iolat->pd); } +static inline void latency_stat_init(struct iolatency_grp *iolat, + struct latency_stat *stat) +{ + if (iolat->ssd) { + stat->ps.total = 0; + stat->ps.missed = 0; + } else + blk_rq_stat_init(&stat->rqs); +} + +static inline void latency_stat_sum(struct iolatency_grp *iolat, + struct latency_stat *sum, + struct latency_stat *stat) +{ + if (iolat->ssd) { + sum->ps.total += stat->ps.total; + sum->ps.missed += stat->ps.missed; + } else + blk_rq_stat_sum(&sum->rqs, &stat->rqs); +} + +static inline void latency_stat_record_time(struct iolatency_grp *iolat, + u64 req_time) +{ + struct latency_stat *stat = get_cpu_ptr(iolat->stats); + if (iolat->ssd) { + if (req_time >= iolat->min_lat_nsec) + stat->ps.missed++; + stat->ps.total++; + } else + blk_rq_stat_add(&stat->rqs, req_time); + put_cpu_ptr(stat); +} + +static inline bool latency_sum_ok(struct iolatency_grp *iolat, + struct latency_stat *stat) +{ + if (iolat->ssd) { + u64 thresh = div64_u64(stat->ps.total, 10); + thresh = max(thresh, 1ULL); + return stat->ps.missed < thresh; + } + return stat->rqs.mean <= iolat->min_lat_nsec; +} + +static inline u64 latency_stat_samples(struct iolatency_grp *iolat, + struct latency_stat *stat) +{ + if (iolat->ssd) + return stat->ps.total; + return stat->rqs.nr_samples; +} + +static inline void iolat_update_total_lat_avg(struct iolatency_grp *iolat, + struct latency_stat *stat) +{ + int exp_idx; + + if (iolat->ssd) + return; + + /* + * CALC_LOAD takes in a number stored in fixed point representation. + * Because we are using this for IO time in ns, the values stored + * are significantly larger than the FIXED_1 denominator (2048). + * Therefore, rounding errors in the calculation are negligible and + * can be ignored. + */ + exp_idx = min_t(int, BLKIOLATENCY_NR_EXP_FACTORS - 1, + div64_u64(iolat->cur_win_nsec, + BLKIOLATENCY_EXP_BUCKET_SIZE)); + CALC_LOAD(iolat->lat_avg, iolatency_exp_factors[exp_idx], stat->rqs.mean); +} + static inline bool iolatency_may_queue(struct iolatency_grp *iolat, wait_queue_entry_t *wait, bool first_block) @@ -255,7 +343,7 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat, struct child_latency_info *lat_info, bool up) { - unsigned long qd = blk_queue_depth(blkiolat->rqos.q); + unsigned long qd = blkiolat->rqos.q->nr_requests; unsigned long scale = scale_amount(qd, up); unsigned long old = atomic_read(&lat_info->scale_cookie); unsigned long max_scale = qd << 1; @@ -295,10 +383,9 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat, */ static void scale_change(struct iolatency_grp *iolat, bool up) { - unsigned long qd = blk_queue_depth(iolat->blkiolat->rqos.q); + unsigned long qd = iolat->blkiolat->rqos.q->nr_requests; unsigned long scale = scale_amount(qd, up); unsigned long old = iolat->rq_depth.max_depth; - bool changed = false; if (old > qd) old = qd; @@ -308,15 +395,13 @@ static void scale_change(struct iolatency_grp *iolat, bool up) return; if (old < qd) { - changed = true; old += scale; old = min(old, qd); iolat->rq_depth.max_depth = old; wake_up_all(&iolat->rq_wait.wait); } - } else if (old > 1) { + } else { old >>= 1; - changed = true; iolat->rq_depth.max_depth = max(old, 1UL); } } @@ -369,7 +454,7 @@ static void check_scale_change(struct iolatency_grp *iolat) * scale down event. */ samples_thresh = lat_info->nr_samples * 5; - samples_thresh = div64_u64(samples_thresh, 100); + samples_thresh = max(1ULL, div64_u64(samples_thresh, 100)); if (iolat->nr_samples <= samples_thresh) return; } @@ -395,34 +480,12 @@ static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio, spinlock_t *lock) { struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos); - struct blkcg *blkcg; - struct blkcg_gq *blkg; - struct request_queue *q = rqos->q; + struct blkcg_gq *blkg = bio->bi_blkg; bool issue_as_root = bio_issue_as_root_blkg(bio); if (!blk_iolatency_enabled(blkiolat)) return; - rcu_read_lock(); - blkcg = bio_blkcg(bio); - bio_associate_blkcg(bio, &blkcg->css); - blkg = blkg_lookup(blkcg, q); - if (unlikely(!blkg)) { - if (!lock) - spin_lock_irq(q->queue_lock); - blkg = blkg_lookup_create(blkcg, q); - if (IS_ERR(blkg)) - blkg = NULL; - if (!lock) - spin_unlock_irq(q->queue_lock); - } - if (!blkg) - goto out; - - bio_issue_init(&bio->bi_issue, bio_sectors(bio)); - bio_associate_blkg(bio, blkg); -out: - rcu_read_unlock(); while (blkg && blkg->parent) { struct iolatency_grp *iolat = blkg_to_lat(blkg); if (!iolat) { @@ -443,7 +506,6 @@ static void iolatency_record_time(struct iolatency_grp *iolat, struct bio_issue *issue, u64 now, bool issue_as_root) { - struct blk_rq_stat *rq_stat; u64 start = bio_issue_time(issue); u64 req_time; @@ -469,9 +531,7 @@ static void iolatency_record_time(struct iolatency_grp *iolat, return; } - rq_stat = get_cpu_ptr(iolat->stats); - blk_rq_stat_add(rq_stat, req_time); - put_cpu_ptr(rq_stat); + latency_stat_record_time(iolat, req_time); } #define BLKIOLATENCY_MIN_ADJUST_TIME (500 * NSEC_PER_MSEC) @@ -482,17 +542,17 @@ static void iolatency_check_latencies(struct iolatency_grp *iolat, u64 now) struct blkcg_gq *blkg = lat_to_blkg(iolat); struct iolatency_grp *parent; struct child_latency_info *lat_info; - struct blk_rq_stat stat; + struct latency_stat stat; unsigned long flags; - int cpu, exp_idx; + int cpu; - blk_rq_stat_init(&stat); + latency_stat_init(iolat, &stat); preempt_disable(); for_each_online_cpu(cpu) { - struct blk_rq_stat *s; + struct latency_stat *s; s = per_cpu_ptr(iolat->stats, cpu); - blk_rq_stat_sum(&stat, s); - blk_rq_stat_init(s); + latency_stat_sum(iolat, &stat, s); + latency_stat_init(iolat, s); } preempt_enable(); @@ -502,41 +562,36 @@ static void iolatency_check_latencies(struct iolatency_grp *iolat, u64 now) lat_info = &parent->child_lat; - /* - * CALC_LOAD takes in a number stored in fixed point representation. - * Because we are using this for IO time in ns, the values stored - * are significantly larger than the FIXED_1 denominator (2048). - * Therefore, rounding errors in the calculation are negligible and - * can be ignored. - */ - exp_idx = min_t(int, BLKIOLATENCY_NR_EXP_FACTORS - 1, - div64_u64(iolat->cur_win_nsec, - BLKIOLATENCY_EXP_BUCKET_SIZE)); - CALC_LOAD(iolat->lat_avg, iolatency_exp_factors[exp_idx], stat.mean); + iolat_update_total_lat_avg(iolat, &stat); /* Everything is ok and we don't need to adjust the scale. */ - if (stat.mean <= iolat->min_lat_nsec && + if (latency_sum_ok(iolat, &stat) && atomic_read(&lat_info->scale_cookie) == DEFAULT_SCALE_COOKIE) return; /* Somebody beat us to the punch, just bail. */ spin_lock_irqsave(&lat_info->lock, flags); + + latency_stat_sum(iolat, &iolat->cur_stat, &stat); lat_info->nr_samples -= iolat->nr_samples; - lat_info->nr_samples += stat.nr_samples; - iolat->nr_samples = stat.nr_samples; + lat_info->nr_samples += latency_stat_samples(iolat, &iolat->cur_stat); + iolat->nr_samples = latency_stat_samples(iolat, &iolat->cur_stat); if ((lat_info->last_scale_event >= now || - now - lat_info->last_scale_event < BLKIOLATENCY_MIN_ADJUST_TIME) && - lat_info->scale_lat <= iolat->min_lat_nsec) + now - lat_info->last_scale_event < BLKIOLATENCY_MIN_ADJUST_TIME)) goto out; - if (stat.mean <= iolat->min_lat_nsec && - stat.nr_samples >= BLKIOLATENCY_MIN_GOOD_SAMPLES) { + if (latency_sum_ok(iolat, &iolat->cur_stat) && + latency_sum_ok(iolat, &stat)) { + if (latency_stat_samples(iolat, &iolat->cur_stat) < + BLKIOLATENCY_MIN_GOOD_SAMPLES) + goto out; if (lat_info->scale_grp == iolat) { lat_info->last_scale_event = now; scale_cookie_change(iolat->blkiolat, lat_info, true); } - } else if (stat.mean > iolat->min_lat_nsec) { + } else if (lat_info->scale_lat == 0 || + lat_info->scale_lat >= iolat->min_lat_nsec) { lat_info->last_scale_event = now; if (!lat_info->scale_grp || lat_info->scale_lat > iolat->min_lat_nsec) { @@ -545,6 +600,7 @@ static void iolatency_check_latencies(struct iolatency_grp *iolat, u64 now) } scale_cookie_change(iolat->blkiolat, lat_info, false); } + latency_stat_init(iolat, &iolat->cur_stat); out: spin_unlock_irqrestore(&lat_info->lock, flags); } @@ -650,7 +706,7 @@ static void blkiolatency_timer_fn(struct timer_list *t) * We could be exiting, don't access the pd unless we have a * ref on the blkg. */ - if (!blkg_try_get(blkg)) + if (!blkg_tryget(blkg)) continue; iolat = blkg_to_lat(blkg); @@ -761,7 +817,6 @@ static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf, { struct blkcg *blkcg = css_to_blkcg(of_css(of)); struct blkcg_gq *blkg; - struct blk_iolatency *blkiolat; struct blkg_conf_ctx ctx; struct iolatency_grp *iolat; char *p, *tok; @@ -774,7 +829,6 @@ static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf, return ret; iolat = blkg_to_lat(ctx.blkg); - blkiolat = iolat->blkiolat; p = ctx.body; ret = -EINVAL; @@ -835,13 +889,43 @@ static int iolatency_print_limit(struct seq_file *sf, void *v) return 0; } +static size_t iolatency_ssd_stat(struct iolatency_grp *iolat, char *buf, + size_t size) +{ + struct latency_stat stat; + int cpu; + + latency_stat_init(iolat, &stat); + preempt_disable(); + for_each_online_cpu(cpu) { + struct latency_stat *s; + s = per_cpu_ptr(iolat->stats, cpu); + latency_stat_sum(iolat, &stat, s); + } + preempt_enable(); + + if (iolat->rq_depth.max_depth == UINT_MAX) + return scnprintf(buf, size, " missed=%llu total=%llu depth=max", + (unsigned long long)stat.ps.missed, + (unsigned long long)stat.ps.total); + return scnprintf(buf, size, " missed=%llu total=%llu depth=%u", + (unsigned long long)stat.ps.missed, + (unsigned long long)stat.ps.total, + iolat->rq_depth.max_depth); +} + static size_t iolatency_pd_stat(struct blkg_policy_data *pd, char *buf, size_t size) { struct iolatency_grp *iolat = pd_to_lat(pd); - unsigned long long avg_lat = div64_u64(iolat->lat_avg, NSEC_PER_USEC); - unsigned long long cur_win = div64_u64(iolat->cur_win_nsec, NSEC_PER_MSEC); + unsigned long long avg_lat; + unsigned long long cur_win; + + if (iolat->ssd) + return iolatency_ssd_stat(iolat, buf, size); + avg_lat = div64_u64(iolat->lat_avg, NSEC_PER_USEC); + cur_win = div64_u64(iolat->cur_win_nsec, NSEC_PER_MSEC); if (iolat->rq_depth.max_depth == UINT_MAX) return scnprintf(buf, size, " depth=max avg_lat=%llu win=%llu", avg_lat, cur_win); @@ -858,8 +942,8 @@ static struct blkg_policy_data *iolatency_pd_alloc(gfp_t gfp, int node) iolat = kzalloc_node(sizeof(*iolat), gfp, node); if (!iolat) return NULL; - iolat->stats = __alloc_percpu_gfp(sizeof(struct blk_rq_stat), - __alignof__(struct blk_rq_stat), gfp); + iolat->stats = __alloc_percpu_gfp(sizeof(struct latency_stat), + __alignof__(struct latency_stat), gfp); if (!iolat->stats) { kfree(iolat); return NULL; @@ -876,15 +960,21 @@ static void iolatency_pd_init(struct blkg_policy_data *pd) u64 now = ktime_to_ns(ktime_get()); int cpu; + if (blk_queue_nonrot(blkg->q)) + iolat->ssd = true; + else + iolat->ssd = false; + for_each_possible_cpu(cpu) { - struct blk_rq_stat *stat; + struct latency_stat *stat; stat = per_cpu_ptr(iolat->stats, cpu); - blk_rq_stat_init(stat); + latency_stat_init(iolat, stat); } + latency_stat_init(iolat, &iolat->cur_stat); rq_wait_init(&iolat->rq_wait); spin_lock_init(&iolat->child_lat.lock); - iolat->rq_depth.queue_depth = blk_queue_depth(blkg->q); + iolat->rq_depth.queue_depth = blkg->q->nr_requests; iolat->rq_depth.max_depth = UINT_MAX; iolat->rq_depth.default_depth = iolat->rq_depth.queue_depth; iolat->blkiolat = blkiolat; diff --git a/block/blk-merge.c b/block/blk-merge.c index aaec38cc37b8..42a46744c11b 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -12,6 +12,69 @@ #include "blk.h" +/* + * Check if the two bvecs from two bios can be merged to one segment. If yes, + * no need to check gap between the two bios since the 1st bio and the 1st bvec + * in the 2nd bio can be handled in one segment. + */ +static inline bool bios_segs_mergeable(struct request_queue *q, + struct bio *prev, struct bio_vec *prev_last_bv, + struct bio_vec *next_first_bv) +{ + if (!biovec_phys_mergeable(q, prev_last_bv, next_first_bv)) + return false; + if (prev->bi_seg_back_size + next_first_bv->bv_len > + queue_max_segment_size(q)) + return false; + return true; +} + +static inline bool bio_will_gap(struct request_queue *q, + struct request *prev_rq, struct bio *prev, struct bio *next) +{ + struct bio_vec pb, nb; + + if (!bio_has_data(prev) || !queue_virt_boundary(q)) + return false; + + /* + * Don't merge if the 1st bio starts with non-zero offset, otherwise it + * is quite difficult to respect the sg gap limit. We work hard to + * merge a huge number of small single bios in case of mkfs. + */ + if (prev_rq) + bio_get_first_bvec(prev_rq->bio, &pb); + else + bio_get_first_bvec(prev, &pb); + if (pb.bv_offset) + return true; + + /* + * We don't need to worry about the situation that the merged segment + * ends in unaligned virt boundary: + * + * - if 'pb' ends aligned, the merged segment ends aligned + * - if 'pb' ends unaligned, the next bio must include + * one single bvec of 'nb', otherwise the 'nb' can't + * merge with 'pb' + */ + bio_get_last_bvec(prev, &pb); + bio_get_first_bvec(next, &nb); + if (bios_segs_mergeable(q, prev, &pb, &nb)) + return false; + return __bvec_gap_to_prev(q, &pb, nb.bv_offset); +} + +static inline bool req_gap_back_merge(struct request *req, struct bio *bio) +{ + return bio_will_gap(req->q, req, req->biotail, bio); +} + +static inline bool req_gap_front_merge(struct request *req, struct bio *bio) +{ + return bio_will_gap(req->q, NULL, bio, req->bio); +} + static struct bio *blk_bio_discard_split(struct request_queue *q, struct bio *bio, struct bio_set *bs, @@ -134,9 +197,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, if (bvprvp && blk_queue_cluster(q)) { if (seg_size + bv.bv_len > queue_max_segment_size(q)) goto new_segment; - if (!BIOVEC_PHYS_MERGEABLE(bvprvp, &bv)) - goto new_segment; - if (!BIOVEC_SEG_BOUNDARY(q, bvprvp, &bv)) + if (!biovec_phys_mergeable(q, bvprvp, &bv)) goto new_segment; seg_size += bv.bv_len; @@ -267,9 +328,7 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, if (seg_size + bv.bv_len > queue_max_segment_size(q)) goto new_segment; - if (!BIOVEC_PHYS_MERGEABLE(&bvprv, &bv)) - goto new_segment; - if (!BIOVEC_SEG_BOUNDARY(q, &bvprv, &bv)) + if (!biovec_phys_mergeable(q, &bvprv, &bv)) goto new_segment; seg_size += bv.bv_len; @@ -349,17 +408,7 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio, bio_get_last_bvec(bio, &end_bv); bio_get_first_bvec(nxt, &nxt_bv); - if (!BIOVEC_PHYS_MERGEABLE(&end_bv, &nxt_bv)) - return 0; - - /* - * bio and nxt are contiguous in memory; check if the queue allows - * these two to be merged into one - */ - if (BIOVEC_SEG_BOUNDARY(q, &end_bv, &nxt_bv)) - return 1; - - return 0; + return biovec_phys_mergeable(q, &end_bv, &nxt_bv); } static inline void @@ -373,10 +422,7 @@ __blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec, if (*sg && *cluster) { if ((*sg)->length + nbytes > queue_max_segment_size(q)) goto new_segment; - - if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec)) - goto new_segment; - if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bvec)) + if (!biovec_phys_mergeable(q, bvprv, bvec)) goto new_segment; (*sg)->length += nbytes; diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index cb1e6cf7ac48..a5ea86835fcb 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -102,6 +102,14 @@ static int blk_flags_show(struct seq_file *m, const unsigned long flags, return 0; } +static int queue_pm_only_show(void *data, struct seq_file *m) +{ + struct request_queue *q = data; + + seq_printf(m, "%d\n", atomic_read(&q->pm_only)); + return 0; +} + #define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name static const char *const blk_queue_flag_name[] = { QUEUE_FLAG_NAME(QUEUED), @@ -132,7 +140,6 @@ static const char *const blk_queue_flag_name[] = { QUEUE_FLAG_NAME(REGISTERED), QUEUE_FLAG_NAME(SCSI_PASSTHROUGH), QUEUE_FLAG_NAME(QUIESCED), - QUEUE_FLAG_NAME(PREEMPT_ONLY), }; #undef QUEUE_FLAG_NAME @@ -209,6 +216,7 @@ static ssize_t queue_write_hint_store(void *data, const char __user *buf, static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = { { "poll_stat", 0400, queue_poll_stat_show }, { "requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops }, + { "pm_only", 0600, queue_pm_only_show, NULL }, { "state", 0600, queue_state_show, queue_state_write }, { "write_hints", 0600, queue_write_hint_show, queue_write_hint_store }, { "zone_wlock", 0400, queue_zone_wlock_show, NULL }, diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index 4e028ee42430..8a9544203173 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -49,12 +49,12 @@ blk_mq_sched_allow_merge(struct request_queue *q, struct request *rq, return true; } -static inline void blk_mq_sched_completed_request(struct request *rq) +static inline void blk_mq_sched_completed_request(struct request *rq, u64 now) { struct elevator_queue *e = rq->q->elevator; if (e && e->type->ops.mq.completed_request) - e->type->ops.mq.completed_request(rq); + e->type->ops.mq.completed_request(rq, now); } static inline void blk_mq_sched_started_request(struct request *rq) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 41317c50a446..cfda95b85d34 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -232,13 +232,26 @@ static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) /* * We can hit rq == NULL here, because the tagging functions - * test and set the bit before assining ->rqs[]. + * test and set the bit before assigning ->rqs[]. */ if (rq && rq->q == hctx->queue) iter_data->fn(hctx, rq, iter_data->data, reserved); return true; } +/** + * bt_for_each - iterate over the requests associated with a hardware queue + * @hctx: Hardware queue to examine. + * @bt: sbitmap to examine. This is either the breserved_tags member + * or the bitmap_tags member of struct blk_mq_tags. + * @fn: Pointer to the function that will be called for each request + * associated with @hctx that has been assigned a driver tag. + * @fn will be called as follows: @fn(@hctx, rq, @data, @reserved) + * where rq is a pointer to a request. + * @data: Will be passed as third argument to @fn. + * @reserved: Indicates whether @bt is the breserved_tags member or the + * bitmap_tags member of struct blk_mq_tags. + */ static void bt_for_each(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt, busy_iter_fn *fn, void *data, bool reserved) { @@ -280,6 +293,18 @@ static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) return true; } +/** + * bt_tags_for_each - iterate over the requests in a tag map + * @tags: Tag map to iterate over. + * @bt: sbitmap to examine. This is either the breserved_tags member + * or the bitmap_tags member of struct blk_mq_tags. + * @fn: Pointer to the function that will be called for each started + * request. @fn will be called as follows: @fn(rq, @data, + * @reserved) where rq is a pointer to a request. + * @data: Will be passed as second argument to @fn. + * @reserved: Indicates whether @bt is the breserved_tags member or the + * bitmap_tags member of struct blk_mq_tags. + */ static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt, busy_tag_iter_fn *fn, void *data, bool reserved) { @@ -294,6 +319,15 @@ static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt, sbitmap_for_each_set(&bt->sb, bt_tags_iter, &iter_data); } +/** + * blk_mq_all_tag_busy_iter - iterate over all started requests in a tag map + * @tags: Tag map to iterate over. + * @fn: Pointer to the function that will be called for each started + * request. @fn will be called as follows: @fn(rq, @priv, + * reserved) where rq is a pointer to a request. 'reserved' + * indicates whether or not @rq is a reserved request. + * @priv: Will be passed as second argument to @fn. + */ static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn, void *priv) { @@ -302,6 +336,15 @@ static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags, bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false); } +/** + * blk_mq_tagset_busy_iter - iterate over all started requests in a tag set + * @tagset: Tag set to iterate over. + * @fn: Pointer to the function that will be called for each started + * request. @fn will be called as follows: @fn(rq, @priv, + * reserved) where rq is a pointer to a request. 'reserved' + * indicates whether or not @rq is a reserved request. + * @priv: Will be passed as second argument to @fn. + */ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, busy_tag_iter_fn *fn, void *priv) { @@ -314,6 +357,20 @@ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, } EXPORT_SYMBOL(blk_mq_tagset_busy_iter); +/** + * blk_mq_queue_tag_busy_iter - iterate over all requests with a driver tag + * @q: Request queue to examine. + * @fn: Pointer to the function that will be called for each request + * on @q. @fn will be called as follows: @fn(hctx, rq, @priv, + * reserved) where rq is a pointer to a request and hctx points + * to the hardware queue associated with the request. 'reserved' + * indicates whether or not @rq is a reserved request. + * @priv: Will be passed as third argument to @fn. + * + * Note: if @q->tag_set is shared with other request queues then @fn will be + * called for all requests on all queues that share that tag set and not only + * for requests associated with @q. + */ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, void *priv) { @@ -321,9 +378,11 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, int i; /* - * __blk_mq_update_nr_hw_queues will update the nr_hw_queues and - * queue_hw_ctx after freeze the queue, so we use q_usage_counter - * to avoid race with it. + * __blk_mq_update_nr_hw_queues() updates nr_hw_queues and queue_hw_ctx + * while the queue is frozen. So we can use q_usage_counter to avoid + * racing with it. __blk_mq_update_nr_hw_queues() uses + * synchronize_rcu() to ensure this function left the critical section + * below. */ if (!percpu_ref_tryget(&q->q_usage_counter)) return; @@ -332,7 +391,7 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, struct blk_mq_tags *tags = hctx->tags; /* - * If not software queues are currently mapped to this + * If no software queues are currently mapped to this * hardware queue, there's nothing to check */ if (!blk_mq_hw_queue_mapped(hctx)) diff --git a/block/blk-mq.c b/block/blk-mq.c index e3c39ea8e17b..1dc157c85a83 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -33,6 +33,7 @@ #include "blk-mq.h" #include "blk-mq-debugfs.h" #include "blk-mq-tag.h" +#include "blk-pm.h" #include "blk-stat.h" #include "blk-mq-sched.h" #include "blk-rq-qos.h" @@ -198,7 +199,7 @@ void blk_mq_unfreeze_queue(struct request_queue *q) freeze_depth = atomic_dec_return(&q->mq_freeze_depth); WARN_ON_ONCE(freeze_depth < 0); if (!freeze_depth) { - percpu_ref_reinit(&q->q_usage_counter); + percpu_ref_resurrect(&q->q_usage_counter); wake_up_all(&q->mq_freeze_wq); } } @@ -475,6 +476,7 @@ static void __blk_mq_free_request(struct request *rq) struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); const int sched_tag = rq->internal_tag; + blk_pm_mark_last_busy(rq); if (rq->tag != -1) blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); if (sched_tag != -1) @@ -526,6 +528,9 @@ inline void __blk_mq_end_request(struct request *rq, blk_status_t error) blk_stat_add(rq, now); } + if (rq->internal_tag != -1) + blk_mq_sched_completed_request(rq, now); + blk_account_io_done(rq, now); if (rq->end_io) { @@ -562,8 +567,6 @@ static void __blk_mq_complete_request(struct request *rq) if (!blk_mq_mark_complete(rq)) return; - if (rq->internal_tag != -1) - blk_mq_sched_completed_request(rq); if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { rq->q->softirq_done_fn(rq); diff --git a/block/blk-pm.c b/block/blk-pm.c new file mode 100644 index 000000000000..f8fdae01bea2 --- /dev/null +++ b/block/blk-pm.c @@ -0,0 +1,216 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/blk-mq.h> +#include <linux/blk-pm.h> +#include <linux/blkdev.h> +#include <linux/pm_runtime.h> +#include "blk-mq.h" +#include "blk-mq-tag.h" + +/** + * blk_pm_runtime_init - Block layer runtime PM initialization routine + * @q: the queue of the device + * @dev: the device the queue belongs to + * + * Description: + * Initialize runtime-PM-related fields for @q and start auto suspend for + * @dev. Drivers that want to take advantage of request-based runtime PM + * should call this function after @dev has been initialized, and its + * request queue @q has been allocated, and runtime PM for it can not happen + * yet(either due to disabled/forbidden or its usage_count > 0). In most + * cases, driver should call this function before any I/O has taken place. + * + * This function takes care of setting up using auto suspend for the device, + * the autosuspend delay is set to -1 to make runtime suspend impossible + * until an updated value is either set by user or by driver. Drivers do + * not need to touch other autosuspend settings. + * + * The block layer runtime PM is request based, so only works for drivers + * that use request as their IO unit instead of those directly use bio's. + */ +void blk_pm_runtime_init(struct request_queue *q, struct device *dev) +{ + q->dev = dev; + q->rpm_status = RPM_ACTIVE; + pm_runtime_set_autosuspend_delay(q->dev, -1); + pm_runtime_use_autosuspend(q->dev); +} +EXPORT_SYMBOL(blk_pm_runtime_init); + +/** + * blk_pre_runtime_suspend - Pre runtime suspend check + * @q: the queue of the device + * + * Description: + * This function will check if runtime suspend is allowed for the device + * by examining if there are any requests pending in the queue. If there + * are requests pending, the device can not be runtime suspended; otherwise, + * the queue's status will be updated to SUSPENDING and the driver can + * proceed to suspend the device. + * + * For the not allowed case, we mark last busy for the device so that + * runtime PM core will try to autosuspend it some time later. + * + * This function should be called near the start of the device's + * runtime_suspend callback. + * + * Return: + * 0 - OK to runtime suspend the device + * -EBUSY - Device should not be runtime suspended + */ +int blk_pre_runtime_suspend(struct request_queue *q) +{ + int ret = 0; + + if (!q->dev) + return ret; + + WARN_ON_ONCE(q->rpm_status != RPM_ACTIVE); + + /* + * Increase the pm_only counter before checking whether any + * non-PM blk_queue_enter() calls are in progress to avoid that any + * new non-PM blk_queue_enter() calls succeed before the pm_only + * counter is decreased again. + */ + blk_set_pm_only(q); + ret = -EBUSY; + /* Switch q_usage_counter from per-cpu to atomic mode. */ + blk_freeze_queue_start(q); + /* + * Wait until atomic mode has been reached. Since that + * involves calling call_rcu(), it is guaranteed that later + * blk_queue_enter() calls see the pm-only state. See also + * http://lwn.net/Articles/573497/. + */ + percpu_ref_switch_to_atomic_sync(&q->q_usage_counter); + if (percpu_ref_is_zero(&q->q_usage_counter)) + ret = 0; + /* Switch q_usage_counter back to per-cpu mode. */ + blk_mq_unfreeze_queue(q); + + spin_lock_irq(q->queue_lock); + if (ret < 0) + pm_runtime_mark_last_busy(q->dev); + else + q->rpm_status = RPM_SUSPENDING; + spin_unlock_irq(q->queue_lock); + + if (ret) + blk_clear_pm_only(q); + + return ret; +} +EXPORT_SYMBOL(blk_pre_runtime_suspend); + +/** + * blk_post_runtime_suspend - Post runtime suspend processing + * @q: the queue of the device + * @err: return value of the device's runtime_suspend function + * + * Description: + * Update the queue's runtime status according to the return value of the + * device's runtime suspend function and mark last busy for the device so + * that PM core will try to auto suspend the device at a later time. + * + * This function should be called near the end of the device's + * runtime_suspend callback. + */ +void blk_post_runtime_suspend(struct request_queue *q, int err) +{ + if (!q->dev) + return; + + spin_lock_irq(q->queue_lock); + if (!err) { + q->rpm_status = RPM_SUSPENDED; + } else { + q->rpm_status = RPM_ACTIVE; + pm_runtime_mark_last_busy(q->dev); + } + spin_unlock_irq(q->queue_lock); + + if (err) + blk_clear_pm_only(q); +} +EXPORT_SYMBOL(blk_post_runtime_suspend); + +/** + * blk_pre_runtime_resume - Pre runtime resume processing + * @q: the queue of the device + * + * Description: + * Update the queue's runtime status to RESUMING in preparation for the + * runtime resume of the device. + * + * This function should be called near the start of the device's + * runtime_resume callback. + */ +void blk_pre_runtime_resume(struct request_queue *q) +{ + if (!q->dev) + return; + + spin_lock_irq(q->queue_lock); + q->rpm_status = RPM_RESUMING; + spin_unlock_irq(q->queue_lock); +} +EXPORT_SYMBOL(blk_pre_runtime_resume); + +/** + * blk_post_runtime_resume - Post runtime resume processing + * @q: the queue of the device + * @err: return value of the device's runtime_resume function + * + * Description: + * Update the queue's runtime status according to the return value of the + * device's runtime_resume function. If it is successfully resumed, process + * the requests that are queued into the device's queue when it is resuming + * and then mark last busy and initiate autosuspend for it. + * + * This function should be called near the end of the device's + * runtime_resume callback. + */ +void blk_post_runtime_resume(struct request_queue *q, int err) +{ + if (!q->dev) + return; + + spin_lock_irq(q->queue_lock); + if (!err) { + q->rpm_status = RPM_ACTIVE; + pm_runtime_mark_last_busy(q->dev); + pm_request_autosuspend(q->dev); + } else { + q->rpm_status = RPM_SUSPENDED; + } + spin_unlock_irq(q->queue_lock); + + if (!err) + blk_clear_pm_only(q); +} +EXPORT_SYMBOL(blk_post_runtime_resume); + +/** + * blk_set_runtime_active - Force runtime status of the queue to be active + * @q: the queue of the device + * + * If the device is left runtime suspended during system suspend the resume + * hook typically resumes the device and corrects runtime status + * accordingly. However, that does not affect the queue runtime PM status + * which is still "suspended". This prevents processing requests from the + * queue. + * + * This function can be used in driver's resume hook to correct queue + * runtime PM status and re-enable peeking requests from the queue. It + * should be called before first request is added to the queue. + */ +void blk_set_runtime_active(struct request_queue *q) +{ + spin_lock_irq(q->queue_lock); + q->rpm_status = RPM_ACTIVE; + pm_runtime_mark_last_busy(q->dev); + pm_request_autosuspend(q->dev); + spin_unlock_irq(q->queue_lock); +} +EXPORT_SYMBOL(blk_set_runtime_active); diff --git a/block/blk-pm.h b/block/blk-pm.h new file mode 100644 index 000000000000..a8564ea72a41 --- /dev/null +++ b/block/blk-pm.h @@ -0,0 +1,69 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _BLOCK_BLK_PM_H_ +#define _BLOCK_BLK_PM_H_ + +#include <linux/pm_runtime.h> + +#ifdef CONFIG_PM +static inline void blk_pm_request_resume(struct request_queue *q) +{ + if (q->dev && (q->rpm_status == RPM_SUSPENDED || + q->rpm_status == RPM_SUSPENDING)) + pm_request_resume(q->dev); +} + +static inline void blk_pm_mark_last_busy(struct request *rq) +{ + if (rq->q->dev && !(rq->rq_flags & RQF_PM)) + pm_runtime_mark_last_busy(rq->q->dev); +} + +static inline void blk_pm_requeue_request(struct request *rq) +{ + lockdep_assert_held(rq->q->queue_lock); + + if (rq->q->dev && !(rq->rq_flags & RQF_PM)) + rq->q->nr_pending--; +} + +static inline void blk_pm_add_request(struct request_queue *q, + struct request *rq) +{ + lockdep_assert_held(q->queue_lock); + + if (q->dev && !(rq->rq_flags & RQF_PM)) + q->nr_pending++; +} + +static inline void blk_pm_put_request(struct request *rq) +{ + lockdep_assert_held(rq->q->queue_lock); + + if (rq->q->dev && !(rq->rq_flags & RQF_PM)) + --rq->q->nr_pending; +} +#else +static inline void blk_pm_request_resume(struct request_queue *q) +{ +} + +static inline void blk_pm_mark_last_busy(struct request *rq) +{ +} + +static inline void blk_pm_requeue_request(struct request *rq) +{ +} + +static inline void blk_pm_add_request(struct request_queue *q, + struct request *rq) +{ +} + +static inline void blk_pm_put_request(struct request *rq) +{ +} +#endif + +#endif /* _BLOCK_BLK_PM_H_ */ diff --git a/block/blk-stat.c b/block/blk-stat.c index 7587b1c3caaf..90561af85a62 100644 --- a/block/blk-stat.c +++ b/block/blk-stat.c @@ -190,6 +190,7 @@ void blk_stat_enable_accounting(struct request_queue *q) blk_queue_flag_set(QUEUE_FLAG_STATS, q); spin_unlock(&q->stats->lock); } +EXPORT_SYMBOL_GPL(blk_stat_enable_accounting); struct blk_queue_stats *blk_alloc_queue_stats(void) { diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 01d0620a4e4a..4bda70e8db48 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -84,8 +84,7 @@ struct throtl_service_queue { * RB tree of active children throtl_grp's, which are sorted by * their ->disptime. */ - struct rb_root pending_tree; /* RB tree of active tgs */ - struct rb_node *first_pending; /* first node in the tree */ + struct rb_root_cached pending_tree; /* RB tree of active tgs */ unsigned int nr_pending; /* # queued in the tree */ unsigned long first_pending_disptime; /* disptime of the first tg */ struct timer_list pending_timer; /* fires on first_pending_disptime */ @@ -475,7 +474,7 @@ static void throtl_service_queue_init(struct throtl_service_queue *sq) { INIT_LIST_HEAD(&sq->queued[0]); INIT_LIST_HEAD(&sq->queued[1]); - sq->pending_tree = RB_ROOT; + sq->pending_tree = RB_ROOT_CACHED; timer_setup(&sq->pending_timer, throtl_pending_timer_fn, 0); } @@ -616,31 +615,23 @@ static void throtl_pd_free(struct blkg_policy_data *pd) static struct throtl_grp * throtl_rb_first(struct throtl_service_queue *parent_sq) { + struct rb_node *n; /* Service tree is empty */ if (!parent_sq->nr_pending) return NULL; - if (!parent_sq->first_pending) - parent_sq->first_pending = rb_first(&parent_sq->pending_tree); - - if (parent_sq->first_pending) - return rb_entry_tg(parent_sq->first_pending); - - return NULL; -} - -static void rb_erase_init(struct rb_node *n, struct rb_root *root) -{ - rb_erase(n, root); - RB_CLEAR_NODE(n); + n = rb_first_cached(&parent_sq->pending_tree); + WARN_ON_ONCE(!n); + if (!n) + return NULL; + return rb_entry_tg(n); } static void throtl_rb_erase(struct rb_node *n, struct throtl_service_queue *parent_sq) { - if (parent_sq->first_pending == n) - parent_sq->first_pending = NULL; - rb_erase_init(n, &parent_sq->pending_tree); + rb_erase_cached(n, &parent_sq->pending_tree); + RB_CLEAR_NODE(n); --parent_sq->nr_pending; } @@ -658,11 +649,11 @@ static void update_min_dispatch_time(struct throtl_service_queue *parent_sq) static void tg_service_queue_add(struct throtl_grp *tg) { struct throtl_service_queue *parent_sq = tg->service_queue.parent_sq; - struct rb_node **node = &parent_sq->pending_tree.rb_node; + struct rb_node **node = &parent_sq->pending_tree.rb_root.rb_node; struct rb_node *parent = NULL; struct throtl_grp *__tg; unsigned long key = tg->disptime; - int left = 1; + bool leftmost = true; while (*node != NULL) { parent = *node; @@ -672,15 +663,13 @@ static void tg_service_queue_add(struct throtl_grp *tg) node = &parent->rb_left; else { node = &parent->rb_right; - left = 0; + leftmost = false; } } - if (left) - parent_sq->first_pending = &tg->rb_node; - rb_link_node(&tg->rb_node, parent, node); - rb_insert_color(&tg->rb_node, &parent_sq->pending_tree); + rb_insert_color_cached(&tg->rb_node, &parent_sq->pending_tree, + leftmost); } static void __throtl_enqueue_tg(struct throtl_grp *tg) @@ -2126,21 +2115,11 @@ static inline void throtl_update_latency_buckets(struct throtl_data *td) } #endif -static void blk_throtl_assoc_bio(struct throtl_grp *tg, struct bio *bio) -{ -#ifdef CONFIG_BLK_DEV_THROTTLING_LOW - /* fallback to root_blkg if we fail to get a blkg ref */ - if (bio->bi_css && (bio_associate_blkg(bio, tg_to_blkg(tg)) == -ENODEV)) - bio_associate_blkg(bio, bio->bi_disk->queue->root_blkg); - bio_issue_init(&bio->bi_issue, bio_sectors(bio)); -#endif -} - bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, struct bio *bio) { struct throtl_qnode *qn = NULL; - struct throtl_grp *tg = blkg_to_tg(blkg ?: q->root_blkg); + struct throtl_grp *tg = blkg_to_tg(blkg); struct throtl_service_queue *sq; bool rw = bio_data_dir(bio); bool throttled = false; @@ -2159,7 +2138,6 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg, if (unlikely(blk_queue_bypass(q))) goto out_unlock; - blk_throtl_assoc_bio(tg, bio); blk_throtl_update_idletime(tg); sq = &tg->service_queue; diff --git a/block/blk.h b/block/blk.h index 9db4e389582c..58c030f727e9 100644 --- a/block/blk.h +++ b/block/blk.h @@ -4,6 +4,7 @@ #include <linux/idr.h> #include <linux/blk-mq.h> +#include <xen/xen.h> #include "blk-mq.h" /* Amount of time in which a process may batch requests */ @@ -149,6 +150,41 @@ static inline void blk_queue_enter_live(struct request_queue *q) percpu_ref_get(&q->q_usage_counter); } +static inline bool biovec_phys_mergeable(struct request_queue *q, + struct bio_vec *vec1, struct bio_vec *vec2) +{ + unsigned long mask = queue_segment_boundary(q); + phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset; + phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset; + + if (addr1 + vec1->bv_len != addr2) + return false; + if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2)) + return false; + if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask)) + return false; + return true; +} + +static inline bool __bvec_gap_to_prev(struct request_queue *q, + struct bio_vec *bprv, unsigned int offset) +{ + return offset || + ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); +} + +/* + * Check if adding a bio_vec after bprv with offset would create a gap in + * the SG list. Most drivers don't care about this, but some do. + */ +static inline bool bvec_gap_to_prev(struct request_queue *q, + struct bio_vec *bprv, unsigned int offset) +{ + if (!queue_virt_boundary(q)) + return false; + return __bvec_gap_to_prev(q, bprv, offset); +} + #ifdef CONFIG_BLK_DEV_INTEGRITY void blk_flush_integrity(void); bool __bio_integrity_endio(struct bio *); @@ -158,7 +194,38 @@ static inline bool bio_integrity_endio(struct bio *bio) return __bio_integrity_endio(bio); return true; } -#else + +static inline bool integrity_req_gap_back_merge(struct request *req, + struct bio *next) +{ + struct bio_integrity_payload *bip = bio_integrity(req->bio); + struct bio_integrity_payload *bip_next = bio_integrity(next); + + return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1], + bip_next->bip_vec[0].bv_offset); +} + +static inline bool integrity_req_gap_front_merge(struct request *req, + struct bio *bio) +{ + struct bio_integrity_payload *bip = bio_integrity(bio); + struct bio_integrity_payload *bip_next = bio_integrity(req->bio); + + return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1], + bip_next->bip_vec[0].bv_offset); +} +#else /* CONFIG_BLK_DEV_INTEGRITY */ +static inline bool integrity_req_gap_back_merge(struct request *req, + struct bio *next) +{ + return false; +} +static inline bool integrity_req_gap_front_merge(struct request *req, + struct bio *bio) +{ + return false; +} + static inline void blk_flush_integrity(void) { } @@ -166,7 +233,7 @@ static inline bool bio_integrity_endio(struct bio *bio) { return true; } -#endif +#endif /* CONFIG_BLK_DEV_INTEGRITY */ void blk_timeout_work(struct work_struct *work); unsigned long blk_rq_timeout(unsigned long timeout); diff --git a/block/bounce.c b/block/bounce.c index bc63b3a2d18c..b30071ac4ec6 100644 --- a/block/bounce.c +++ b/block/bounce.c @@ -257,7 +257,9 @@ static struct bio *bounce_clone_bio(struct bio *bio_src, gfp_t gfp_mask, } } - bio_clone_blkcg_association(bio, bio_src); + bio_clone_blkg_association(bio, bio_src); + + blkcg_bio_issue_init(bio); return bio; } diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 2eb87444b157..d219e9a1af65 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -3753,7 +3753,7 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) uint64_t serial_nr; rcu_read_lock(); - serial_nr = bio_blkcg(bio)->css.serial_nr; + serial_nr = __bio_blkcg(bio)->css.serial_nr; rcu_read_unlock(); /* @@ -3818,7 +3818,7 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, struct cfq_group *cfqg; rcu_read_lock(); - cfqg = cfq_lookup_cfqg(cfqd, bio_blkcg(bio)); + cfqg = cfq_lookup_cfqg(cfqd, __bio_blkcg(bio)); if (!cfqg) { cfqq = &cfqd->oom_cfqq; goto out; diff --git a/block/elevator.c b/block/elevator.c index fae58b2f906f..8fdcd64ae12e 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -41,6 +41,7 @@ #include "blk.h" #include "blk-mq-sched.h" +#include "blk-pm.h" #include "blk-wbt.h" static DEFINE_SPINLOCK(elv_list_lock); @@ -557,27 +558,6 @@ void elv_bio_merged(struct request_queue *q, struct request *rq, e->type->ops.sq.elevator_bio_merged_fn(q, rq, bio); } -#ifdef CONFIG_PM -static void blk_pm_requeue_request(struct request *rq) -{ - if (rq->q->dev && !(rq->rq_flags & RQF_PM)) - rq->q->nr_pending--; -} - -static void blk_pm_add_request(struct request_queue *q, struct request *rq) -{ - if (q->dev && !(rq->rq_flags & RQF_PM) && q->nr_pending++ == 0 && - (q->rpm_status == RPM_SUSPENDED || q->rpm_status == RPM_SUSPENDING)) - pm_request_resume(q->dev); -} -#else -static inline void blk_pm_requeue_request(struct request *rq) {} -static inline void blk_pm_add_request(struct request_queue *q, - struct request *rq) -{ -} -#endif - void elv_requeue_request(struct request_queue *q, struct request *rq) { /* diff --git a/block/genhd.c b/block/genhd.c index be5bab20b2ab..cff6bdf27226 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -567,7 +567,8 @@ static int exact_lock(dev_t devt, void *data) return 0; } -static void register_disk(struct device *parent, struct gendisk *disk) +static void register_disk(struct device *parent, struct gendisk *disk, + const struct attribute_group **groups) { struct device *ddev = disk_to_dev(disk); struct block_device *bdev; @@ -582,6 +583,10 @@ static void register_disk(struct device *parent, struct gendisk *disk) /* delay uevents, until we scanned partition table */ dev_set_uevent_suppress(ddev, 1); + if (groups) { + WARN_ON(ddev->groups); + ddev->groups = groups; + } if (device_add(ddev)) return; if (!sysfs_deprecated) { @@ -647,6 +652,7 @@ exit: * __device_add_disk - add disk information to kernel list * @parent: parent device for the disk * @disk: per-device partitioning information + * @groups: Additional per-device sysfs groups * @register_queue: register the queue if set to true * * This function registers the partitioning information in @disk @@ -655,6 +661,7 @@ exit: * FIXME: error handling */ static void __device_add_disk(struct device *parent, struct gendisk *disk, + const struct attribute_group **groups, bool register_queue) { dev_t devt; @@ -698,7 +705,7 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk, blk_register_region(disk_devt(disk), disk->minors, NULL, exact_match, exact_lock, disk); } - register_disk(parent, disk); + register_disk(parent, disk, groups); if (register_queue) blk_register_queue(disk); @@ -712,15 +719,17 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk, blk_integrity_add(disk); } -void device_add_disk(struct device *parent, struct gendisk *disk) +void device_add_disk(struct device *parent, struct gendisk *disk, + const struct attribute_group **groups) + { - __device_add_disk(parent, disk, true); + __device_add_disk(parent, disk, groups, true); } EXPORT_SYMBOL(device_add_disk); void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk) { - __device_add_disk(parent, disk, false); + __device_add_disk(parent, disk, NULL, false); } EXPORT_SYMBOL(device_add_disk_no_queue_reg); diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c index a1660bafc912..eccac01a10b6 100644 --- a/block/kyber-iosched.c +++ b/block/kyber-iosched.c @@ -29,19 +29,30 @@ #include "blk-mq-debugfs.h" #include "blk-mq-sched.h" #include "blk-mq-tag.h" -#include "blk-stat.h" -/* Scheduling domains. */ +#define CREATE_TRACE_POINTS +#include <trace/events/kyber.h> + +/* + * Scheduling domains: the device is divided into multiple domains based on the + * request type. + */ enum { KYBER_READ, - KYBER_SYNC_WRITE, - KYBER_OTHER, /* Async writes, discard, etc. */ + KYBER_WRITE, + KYBER_DISCARD, + KYBER_OTHER, KYBER_NUM_DOMAINS, }; -enum { - KYBER_MIN_DEPTH = 256, +static const char *kyber_domain_names[] = { + [KYBER_READ] = "READ", + [KYBER_WRITE] = "WRITE", + [KYBER_DISCARD] = "DISCARD", + [KYBER_OTHER] = "OTHER", +}; +enum { /* * In order to prevent starvation of synchronous requests by a flood of * asynchronous requests, we reserve 25% of requests for synchronous @@ -51,25 +62,87 @@ enum { }; /* - * Initial device-wide depths for each scheduling domain. + * Maximum device-wide depth for each scheduling domain. * - * Even for fast devices with lots of tags like NVMe, you can saturate - * the device with only a fraction of the maximum possible queue depth. - * So, we cap these to a reasonable value. + * Even for fast devices with lots of tags like NVMe, you can saturate the + * device with only a fraction of the maximum possible queue depth. So, we cap + * these to a reasonable value. */ static const unsigned int kyber_depth[] = { [KYBER_READ] = 256, - [KYBER_SYNC_WRITE] = 128, - [KYBER_OTHER] = 64, + [KYBER_WRITE] = 128, + [KYBER_DISCARD] = 64, + [KYBER_OTHER] = 16, }; /* - * Scheduling domain batch sizes. We favor reads. + * Default latency targets for each scheduling domain. + */ +static const u64 kyber_latency_targets[] = { + [KYBER_READ] = 2ULL * NSEC_PER_MSEC, + [KYBER_WRITE] = 10ULL * NSEC_PER_MSEC, + [KYBER_DISCARD] = 5ULL * NSEC_PER_SEC, +}; + +/* + * Batch size (number of requests we'll dispatch in a row) for each scheduling + * domain. */ static const unsigned int kyber_batch_size[] = { [KYBER_READ] = 16, - [KYBER_SYNC_WRITE] = 8, - [KYBER_OTHER] = 8, + [KYBER_WRITE] = 8, + [KYBER_DISCARD] = 1, + [KYBER_OTHER] = 1, +}; + +/* + * Requests latencies are recorded in a histogram with buckets defined relative + * to the target latency: + * + * <= 1/4 * target latency + * <= 1/2 * target latency + * <= 3/4 * target latency + * <= target latency + * <= 1 1/4 * target latency + * <= 1 1/2 * target latency + * <= 1 3/4 * target latency + * > 1 3/4 * target latency + */ +enum { + /* + * The width of the latency histogram buckets is + * 1 / (1 << KYBER_LATENCY_SHIFT) * target latency. + */ + KYBER_LATENCY_SHIFT = 2, + /* + * The first (1 << KYBER_LATENCY_SHIFT) buckets are <= target latency, + * thus, "good". + */ + KYBER_GOOD_BUCKETS = 1 << KYBER_LATENCY_SHIFT, + /* There are also (1 << KYBER_LATENCY_SHIFT) "bad" buckets. */ + KYBER_LATENCY_BUCKETS = 2 << KYBER_LATENCY_SHIFT, +}; + +/* + * We measure both the total latency and the I/O latency (i.e., latency after + * submitting to the device). + */ +enum { + KYBER_TOTAL_LATENCY, + KYBER_IO_LATENCY, +}; + +static const char *kyber_latency_type_names[] = { + [KYBER_TOTAL_LATENCY] = "total", + [KYBER_IO_LATENCY] = "I/O", +}; + +/* + * Per-cpu latency histograms: total latency and I/O latency for each scheduling + * domain except for KYBER_OTHER. + */ +struct kyber_cpu_latency { + atomic_t buckets[KYBER_OTHER][2][KYBER_LATENCY_BUCKETS]; }; /* @@ -88,12 +161,9 @@ struct kyber_ctx_queue { struct kyber_queue_data { struct request_queue *q; - struct blk_stat_callback *cb; - /* - * The device is divided into multiple scheduling domains based on the - * request type. Each domain has a fixed number of in-flight requests of - * that type device-wide, limited by these tokens. + * Each scheduling domain has a limited number of in-flight requests + * device-wide, limited by these tokens. */ struct sbitmap_queue domain_tokens[KYBER_NUM_DOMAINS]; @@ -103,8 +173,19 @@ struct kyber_queue_data { */ unsigned int async_depth; + struct kyber_cpu_latency __percpu *cpu_latency; + + /* Timer for stats aggregation and adjusting domain tokens. */ + struct timer_list timer; + + unsigned int latency_buckets[KYBER_OTHER][2][KYBER_LATENCY_BUCKETS]; + + unsigned long latency_timeout[KYBER_OTHER]; + + int domain_p99[KYBER_OTHER]; + /* Target latencies in nanoseconds. */ - u64 read_lat_nsec, write_lat_nsec; + u64 latency_targets[KYBER_OTHER]; }; struct kyber_hctx_data { @@ -124,233 +205,219 @@ static int kyber_domain_wake(wait_queue_entry_t *wait, unsigned mode, int flags, static unsigned int kyber_sched_domain(unsigned int op) { - if ((op & REQ_OP_MASK) == REQ_OP_READ) + switch (op & REQ_OP_MASK) { + case REQ_OP_READ: return KYBER_READ; - else if ((op & REQ_OP_MASK) == REQ_OP_WRITE && op_is_sync(op)) - return KYBER_SYNC_WRITE; - else + case REQ_OP_WRITE: + return KYBER_WRITE; + case REQ_OP_DISCARD: + return KYBER_DISCARD; + default: return KYBER_OTHER; + } } -enum { - NONE = 0, - GOOD = 1, - GREAT = 2, - BAD = -1, - AWFUL = -2, -}; - -#define IS_GOOD(status) ((status) > 0) -#define IS_BAD(status) ((status) < 0) - -static int kyber_lat_status(struct blk_stat_callback *cb, - unsigned int sched_domain, u64 target) +static void flush_latency_buckets(struct kyber_queue_data *kqd, + struct kyber_cpu_latency *cpu_latency, + unsigned int sched_domain, unsigned int type) { - u64 latency; - - if (!cb->stat[sched_domain].nr_samples) - return NONE; + unsigned int *buckets = kqd->latency_buckets[sched_domain][type]; + atomic_t *cpu_buckets = cpu_latency->buckets[sched_domain][type]; + unsigned int bucket; - latency = cb->stat[sched_domain].mean; - if (latency >= 2 * target) - return AWFUL; - else if (latency > target) - return BAD; - else if (latency <= target / 2) - return GREAT; - else /* (latency <= target) */ - return GOOD; + for (bucket = 0; bucket < KYBER_LATENCY_BUCKETS; bucket++) + buckets[bucket] += atomic_xchg(&cpu_buckets[bucket], 0); } /* - * Adjust the read or synchronous write depth given the status of reads and - * writes. The goal is that the latencies of the two domains are fair (i.e., if - * one is good, then the other is good). + * Calculate the histogram bucket with the given percentile rank, or -1 if there + * aren't enough samples yet. */ -static void kyber_adjust_rw_depth(struct kyber_queue_data *kqd, - unsigned int sched_domain, int this_status, - int other_status) +static int calculate_percentile(struct kyber_queue_data *kqd, + unsigned int sched_domain, unsigned int type, + unsigned int percentile) { - unsigned int orig_depth, depth; + unsigned int *buckets = kqd->latency_buckets[sched_domain][type]; + unsigned int bucket, samples = 0, percentile_samples; + + for (bucket = 0; bucket < KYBER_LATENCY_BUCKETS; bucket++) + samples += buckets[bucket]; + + if (!samples) + return -1; /* - * If this domain had no samples, or reads and writes are both good or - * both bad, don't adjust the depth. + * We do the calculation once we have 500 samples or one second passes + * since the first sample was recorded, whichever comes first. */ - if (this_status == NONE || - (IS_GOOD(this_status) && IS_GOOD(other_status)) || - (IS_BAD(this_status) && IS_BAD(other_status))) - return; - - orig_depth = depth = kqd->domain_tokens[sched_domain].sb.depth; + if (!kqd->latency_timeout[sched_domain]) + kqd->latency_timeout[sched_domain] = max(jiffies + HZ, 1UL); + if (samples < 500 && + time_is_after_jiffies(kqd->latency_timeout[sched_domain])) { + return -1; + } + kqd->latency_timeout[sched_domain] = 0; - if (other_status == NONE) { - depth++; - } else { - switch (this_status) { - case GOOD: - if (other_status == AWFUL) - depth -= max(depth / 4, 1U); - else - depth -= max(depth / 8, 1U); - break; - case GREAT: - if (other_status == AWFUL) - depth /= 2; - else - depth -= max(depth / 4, 1U); + percentile_samples = DIV_ROUND_UP(samples * percentile, 100); + for (bucket = 0; bucket < KYBER_LATENCY_BUCKETS - 1; bucket++) { + if (buckets[bucket] >= percentile_samples) break; - case BAD: - depth++; - break; - case AWFUL: - if (other_status == GREAT) - depth += 2; - else - depth++; - break; - } + percentile_samples -= buckets[bucket]; } + memset(buckets, 0, sizeof(kqd->latency_buckets[sched_domain][type])); - depth = clamp(depth, 1U, kyber_depth[sched_domain]); - if (depth != orig_depth) - sbitmap_queue_resize(&kqd->domain_tokens[sched_domain], depth); + trace_kyber_latency(kqd->q, kyber_domain_names[sched_domain], + kyber_latency_type_names[type], percentile, + bucket + 1, 1 << KYBER_LATENCY_SHIFT, samples); + + return bucket; } -/* - * Adjust the depth of other requests given the status of reads and synchronous - * writes. As long as either domain is doing fine, we don't throttle, but if - * both domains are doing badly, we throttle heavily. - */ -static void kyber_adjust_other_depth(struct kyber_queue_data *kqd, - int read_status, int write_status, - bool have_samples) -{ - unsigned int orig_depth, depth; - int status; - - orig_depth = depth = kqd->domain_tokens[KYBER_OTHER].sb.depth; - - if (read_status == NONE && write_status == NONE) { - depth += 2; - } else if (have_samples) { - if (read_status == NONE) - status = write_status; - else if (write_status == NONE) - status = read_status; - else - status = max(read_status, write_status); - switch (status) { - case GREAT: - depth += 2; - break; - case GOOD: - depth++; - break; - case BAD: - depth -= max(depth / 4, 1U); - break; - case AWFUL: - depth /= 2; - break; - } +static void kyber_resize_domain(struct kyber_queue_data *kqd, + unsigned int sched_domain, unsigned int depth) +{ + depth = clamp(depth, 1U, kyber_depth[sched_domain]); + if (depth != kqd->domain_tokens[sched_domain].sb.depth) { + sbitmap_queue_resize(&kqd->domain_tokens[sched_domain], depth); + trace_kyber_adjust(kqd->q, kyber_domain_names[sched_domain], + depth); } - - depth = clamp(depth, 1U, kyber_depth[KYBER_OTHER]); - if (depth != orig_depth) - sbitmap_queue_resize(&kqd->domain_tokens[KYBER_OTHER], depth); } -/* - * Apply heuristics for limiting queue depths based on gathered latency - * statistics. - */ -static void kyber_stat_timer_fn(struct blk_stat_callback *cb) +static void kyber_timer_fn(struct timer_list *t) { - struct kyber_queue_data *kqd = cb->data; - int read_status, write_status; + struct kyber_queue_data *kqd = from_timer(kqd, t, timer); + unsigned int sched_domain; + int cpu; + bool bad = false; + + /* Sum all of the per-cpu latency histograms. */ + for_each_online_cpu(cpu) { + struct kyber_cpu_latency *cpu_latency; + + cpu_latency = per_cpu_ptr(kqd->cpu_latency, cpu); + for (sched_domain = 0; sched_domain < KYBER_OTHER; sched_domain++) { + flush_latency_buckets(kqd, cpu_latency, sched_domain, + KYBER_TOTAL_LATENCY); + flush_latency_buckets(kqd, cpu_latency, sched_domain, + KYBER_IO_LATENCY); + } + } - read_status = kyber_lat_status(cb, KYBER_READ, kqd->read_lat_nsec); - write_status = kyber_lat_status(cb, KYBER_SYNC_WRITE, kqd->write_lat_nsec); + /* + * Check if any domains have a high I/O latency, which might indicate + * congestion in the device. Note that we use the p90; we don't want to + * be too sensitive to outliers here. + */ + for (sched_domain = 0; sched_domain < KYBER_OTHER; sched_domain++) { + int p90; - kyber_adjust_rw_depth(kqd, KYBER_READ, read_status, write_status); - kyber_adjust_rw_depth(kqd, KYBER_SYNC_WRITE, write_status, read_status); - kyber_adjust_other_depth(kqd, read_status, write_status, - cb->stat[KYBER_OTHER].nr_samples != 0); + p90 = calculate_percentile(kqd, sched_domain, KYBER_IO_LATENCY, + 90); + if (p90 >= KYBER_GOOD_BUCKETS) + bad = true; + } /* - * Continue monitoring latencies if we aren't hitting the targets or - * we're still throttling other requests. + * Adjust the scheduling domain depths. If we determined that there was + * congestion, we throttle all domains with good latencies. Either way, + * we ease up on throttling domains with bad latencies. */ - if (!blk_stat_is_active(kqd->cb) && - ((IS_BAD(read_status) || IS_BAD(write_status) || - kqd->domain_tokens[KYBER_OTHER].sb.depth < kyber_depth[KYBER_OTHER]))) - blk_stat_activate_msecs(kqd->cb, 100); + for (sched_domain = 0; sched_domain < KYBER_OTHER; sched_domain++) { + unsigned int orig_depth, depth; + int p99; + + p99 = calculate_percentile(kqd, sched_domain, + KYBER_TOTAL_LATENCY, 99); + /* + * This is kind of subtle: different domains will not + * necessarily have enough samples to calculate the latency + * percentiles during the same window, so we have to remember + * the p99 for the next time we observe congestion; once we do, + * we don't want to throttle again until we get more data, so we + * reset it to -1. + */ + if (bad) { + if (p99 < 0) + p99 = kqd->domain_p99[sched_domain]; + kqd->domain_p99[sched_domain] = -1; + } else if (p99 >= 0) { + kqd->domain_p99[sched_domain] = p99; + } + if (p99 < 0) + continue; + + /* + * If this domain has bad latency, throttle less. Otherwise, + * throttle more iff we determined that there is congestion. + * + * The new depth is scaled linearly with the p99 latency vs the + * latency target. E.g., if the p99 is 3/4 of the target, then + * we throttle down to 3/4 of the current depth, and if the p99 + * is 2x the target, then we double the depth. + */ + if (bad || p99 >= KYBER_GOOD_BUCKETS) { + orig_depth = kqd->domain_tokens[sched_domain].sb.depth; + depth = (orig_depth * (p99 + 1)) >> KYBER_LATENCY_SHIFT; + kyber_resize_domain(kqd, sched_domain, depth); + } + } } -static unsigned int kyber_sched_tags_shift(struct kyber_queue_data *kqd) +static unsigned int kyber_sched_tags_shift(struct request_queue *q) { /* * All of the hardware queues have the same depth, so we can just grab * the shift of the first one. */ - return kqd->q->queue_hw_ctx[0]->sched_tags->bitmap_tags.sb.shift; -} - -static int kyber_bucket_fn(const struct request *rq) -{ - return kyber_sched_domain(rq->cmd_flags); + return q->queue_hw_ctx[0]->sched_tags->bitmap_tags.sb.shift; } static struct kyber_queue_data *kyber_queue_data_alloc(struct request_queue *q) { struct kyber_queue_data *kqd; - unsigned int max_tokens; unsigned int shift; int ret = -ENOMEM; int i; - kqd = kmalloc_node(sizeof(*kqd), GFP_KERNEL, q->node); + kqd = kzalloc_node(sizeof(*kqd), GFP_KERNEL, q->node); if (!kqd) goto err; + kqd->q = q; - kqd->cb = blk_stat_alloc_callback(kyber_stat_timer_fn, kyber_bucket_fn, - KYBER_NUM_DOMAINS, kqd); - if (!kqd->cb) + kqd->cpu_latency = alloc_percpu_gfp(struct kyber_cpu_latency, + GFP_KERNEL | __GFP_ZERO); + if (!kqd->cpu_latency) goto err_kqd; - /* - * The maximum number of tokens for any scheduling domain is at least - * the queue depth of a single hardware queue. If the hardware doesn't - * have many tags, still provide a reasonable number. - */ - max_tokens = max_t(unsigned int, q->tag_set->queue_depth, - KYBER_MIN_DEPTH); + timer_setup(&kqd->timer, kyber_timer_fn, 0); + for (i = 0; i < KYBER_NUM_DOMAINS; i++) { WARN_ON(!kyber_depth[i]); WARN_ON(!kyber_batch_size[i]); ret = sbitmap_queue_init_node(&kqd->domain_tokens[i], - max_tokens, -1, false, GFP_KERNEL, - q->node); + kyber_depth[i], -1, false, + GFP_KERNEL, q->node); if (ret) { while (--i >= 0) sbitmap_queue_free(&kqd->domain_tokens[i]); - goto err_cb; + goto err_buckets; } - sbitmap_queue_resize(&kqd->domain_tokens[i], kyber_depth[i]); } - shift = kyber_sched_tags_shift(kqd); - kqd->async_depth = (1U << shift) * KYBER_ASYNC_PERCENT / 100U; + for (i = 0; i < KYBER_OTHER; i++) { + kqd->domain_p99[i] = -1; + kqd->latency_targets[i] = kyber_latency_targets[i]; + } - kqd->read_lat_nsec = 2000000ULL; - kqd->write_lat_nsec = 10000000ULL; + shift = kyber_sched_tags_shift(q); + kqd->async_depth = (1U << shift) * KYBER_ASYNC_PERCENT / 100U; return kqd; -err_cb: - blk_stat_free_callback(kqd->cb); +err_buckets: + free_percpu(kqd->cpu_latency); err_kqd: kfree(kqd); err: @@ -372,25 +439,24 @@ static int kyber_init_sched(struct request_queue *q, struct elevator_type *e) return PTR_ERR(kqd); } + blk_stat_enable_accounting(q); + eq->elevator_data = kqd; q->elevator = eq; - blk_stat_add_callback(q, kqd->cb); - return 0; } static void kyber_exit_sched(struct elevator_queue *e) { struct kyber_queue_data *kqd = e->elevator_data; - struct request_queue *q = kqd->q; int i; - blk_stat_remove_callback(q, kqd->cb); + del_timer_sync(&kqd->timer); for (i = 0; i < KYBER_NUM_DOMAINS; i++) sbitmap_queue_free(&kqd->domain_tokens[i]); - blk_stat_free_callback(kqd->cb); + free_percpu(kqd->cpu_latency); kfree(kqd); } @@ -558,41 +624,44 @@ static void kyber_finish_request(struct request *rq) rq_clear_domain_token(kqd, rq); } -static void kyber_completed_request(struct request *rq) +static void add_latency_sample(struct kyber_cpu_latency *cpu_latency, + unsigned int sched_domain, unsigned int type, + u64 target, u64 latency) { - struct request_queue *q = rq->q; - struct kyber_queue_data *kqd = q->elevator->elevator_data; - unsigned int sched_domain; - u64 now, latency, target; + unsigned int bucket; + u64 divisor; - /* - * Check if this request met our latency goal. If not, quickly gather - * some statistics and start throttling. - */ - sched_domain = kyber_sched_domain(rq->cmd_flags); - switch (sched_domain) { - case KYBER_READ: - target = kqd->read_lat_nsec; - break; - case KYBER_SYNC_WRITE: - target = kqd->write_lat_nsec; - break; - default: - return; + if (latency > 0) { + divisor = max_t(u64, target >> KYBER_LATENCY_SHIFT, 1); + bucket = min_t(unsigned int, div64_u64(latency - 1, divisor), + KYBER_LATENCY_BUCKETS - 1); + } else { + bucket = 0; } - /* If we are already monitoring latencies, don't check again. */ - if (blk_stat_is_active(kqd->cb)) - return; + atomic_inc(&cpu_latency->buckets[sched_domain][type][bucket]); +} - now = ktime_get_ns(); - if (now < rq->io_start_time_ns) +static void kyber_completed_request(struct request *rq, u64 now) +{ + struct kyber_queue_data *kqd = rq->q->elevator->elevator_data; + struct kyber_cpu_latency *cpu_latency; + unsigned int sched_domain; + u64 target; + + sched_domain = kyber_sched_domain(rq->cmd_flags); + if (sched_domain == KYBER_OTHER) return; - latency = now - rq->io_start_time_ns; + cpu_latency = get_cpu_ptr(kqd->cpu_latency); + target = kqd->latency_targets[sched_domain]; + add_latency_sample(cpu_latency, sched_domain, KYBER_TOTAL_LATENCY, + target, now - rq->start_time_ns); + add_latency_sample(cpu_latency, sched_domain, KYBER_IO_LATENCY, target, + now - rq->io_start_time_ns); + put_cpu_ptr(kqd->cpu_latency); - if (latency > target) - blk_stat_activate_msecs(kqd->cb, 10); + timer_reduce(&kqd->timer, jiffies + HZ / 10); } struct flush_kcq_data { @@ -713,6 +782,9 @@ kyber_dispatch_cur_domain(struct kyber_queue_data *kqd, rq_set_domain_token(rq, nr); list_del_init(&rq->queuelist); return rq; + } else { + trace_kyber_throttled(kqd->q, + kyber_domain_names[khd->cur_domain]); } } else if (sbitmap_any_bit_set(&khd->kcq_map[khd->cur_domain])) { nr = kyber_get_domain_token(kqd, khd, hctx); @@ -723,6 +795,9 @@ kyber_dispatch_cur_domain(struct kyber_queue_data *kqd, rq_set_domain_token(rq, nr); list_del_init(&rq->queuelist); return rq; + } else { + trace_kyber_throttled(kqd->q, + kyber_domain_names[khd->cur_domain]); } } @@ -790,17 +865,17 @@ static bool kyber_has_work(struct blk_mq_hw_ctx *hctx) return false; } -#define KYBER_LAT_SHOW_STORE(op) \ -static ssize_t kyber_##op##_lat_show(struct elevator_queue *e, \ - char *page) \ +#define KYBER_LAT_SHOW_STORE(domain, name) \ +static ssize_t kyber_##name##_lat_show(struct elevator_queue *e, \ + char *page) \ { \ struct kyber_queue_data *kqd = e->elevator_data; \ \ - return sprintf(page, "%llu\n", kqd->op##_lat_nsec); \ + return sprintf(page, "%llu\n", kqd->latency_targets[domain]); \ } \ \ -static ssize_t kyber_##op##_lat_store(struct elevator_queue *e, \ - const char *page, size_t count) \ +static ssize_t kyber_##name##_lat_store(struct elevator_queue *e, \ + const char *page, size_t count) \ { \ struct kyber_queue_data *kqd = e->elevator_data; \ unsigned long long nsec; \ @@ -810,12 +885,12 @@ static ssize_t kyber_##op##_lat_store(struct elevator_queue *e, \ if (ret) \ return ret; \ \ - kqd->op##_lat_nsec = nsec; \ + kqd->latency_targets[domain] = nsec; \ \ return count; \ } -KYBER_LAT_SHOW_STORE(read); -KYBER_LAT_SHOW_STORE(write); +KYBER_LAT_SHOW_STORE(KYBER_READ, read); +KYBER_LAT_SHOW_STORE(KYBER_WRITE, write); #undef KYBER_LAT_SHOW_STORE #define KYBER_LAT_ATTR(op) __ATTR(op##_lat_nsec, 0644, kyber_##op##_lat_show, kyber_##op##_lat_store) @@ -882,7 +957,8 @@ static int kyber_##name##_waiting_show(void *data, struct seq_file *m) \ return 0; \ } KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_READ, read) -KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_SYNC_WRITE, sync_write) +KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_WRITE, write) +KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_DISCARD, discard) KYBER_DEBUGFS_DOMAIN_ATTRS(KYBER_OTHER, other) #undef KYBER_DEBUGFS_DOMAIN_ATTRS @@ -900,20 +976,7 @@ static int kyber_cur_domain_show(void *data, struct seq_file *m) struct blk_mq_hw_ctx *hctx = data; struct kyber_hctx_data *khd = hctx->sched_data; - switch (khd->cur_domain) { - case KYBER_READ: - seq_puts(m, "READ\n"); - break; - case KYBER_SYNC_WRITE: - seq_puts(m, "SYNC_WRITE\n"); - break; - case KYBER_OTHER: - seq_puts(m, "OTHER\n"); - break; - default: - seq_printf(m, "%u\n", khd->cur_domain); - break; - } + seq_printf(m, "%s\n", kyber_domain_names[khd->cur_domain]); return 0; } @@ -930,7 +993,8 @@ static int kyber_batching_show(void *data, struct seq_file *m) {#name "_tokens", 0400, kyber_##name##_tokens_show} static const struct blk_mq_debugfs_attr kyber_queue_debugfs_attrs[] = { KYBER_QUEUE_DOMAIN_ATTRS(read), - KYBER_QUEUE_DOMAIN_ATTRS(sync_write), + KYBER_QUEUE_DOMAIN_ATTRS(write), + KYBER_QUEUE_DOMAIN_ATTRS(discard), KYBER_QUEUE_DOMAIN_ATTRS(other), {"async_depth", 0400, kyber_async_depth_show}, {}, @@ -942,7 +1006,8 @@ static const struct blk_mq_debugfs_attr kyber_queue_debugfs_attrs[] = { {#name "_waiting", 0400, kyber_##name##_waiting_show} static const struct blk_mq_debugfs_attr kyber_hctx_debugfs_attrs[] = { KYBER_HCTX_DOMAIN_ATTRS(read), - KYBER_HCTX_DOMAIN_ATTRS(sync_write), + KYBER_HCTX_DOMAIN_ATTRS(write), + KYBER_HCTX_DOMAIN_ATTRS(discard), KYBER_HCTX_DOMAIN_ATTRS(other), {"cur_domain", 0400, kyber_cur_domain_show}, {"batching", 0400, kyber_batching_show}, |