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[2.35.55.161]) by smtp.gmail.com with ESMTPSA id d27-20020a170906305b00b0073d71792c8dsm1666088ejd.180.2022.10.30.03.03.37 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 30 Oct 2022 03:03:38 -0700 (PDT) From: Paolo Valente To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Paolo Valente , Gabriele Felici , Gianmarco Lusvardi , Giulio Barabino , Emiliano Maccaferri Subject: [PATCH V5 4/8] block, bfq: turn bfqq_data into an array in bfq_io_cq Date: Sun, 30 Oct 2022 11:02:56 +0100 Message-Id: <20221030100300.3085-5-paolo.valente@linaro.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20221030100300.3085-1-paolo.valente@linaro.org> References: <20221030100300.3085-1-paolo.valente@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org When a bfq_queue Q is merged with another queue, several pieces of information are saved about Q. These pieces are stored in the bfqq_data field in the bfq_io_cq data structure of the process associated with Q. Yet, with a multi-actuator drive, a process may get associated with multiple bfq_queues: one queue for each of the N actuators. Each of these queues may undergo a merge. So, the bfq_io_cq data structure must be able to accommodate the above information for N queues. This commit solves this problem by turning the bfqq_data scalar field into an array of N elements (and by changing code so as to handle this array). This solution is written under the assumption that bfq_queues associated with different actuators cannot be cross-merged. This assumption holds naturally with basic queue merging: the latter is triggered by spatial locality, and sectors for different actuators are not close to each other. As for stable cross-merging, the assumption here is that it is disabled. Signed-off-by: Gabriele Felici Signed-off-by: Gianmarco Lusvardi Signed-off-by: Giulio Barabino Signed-off-by: Emiliano Maccaferri Signed-off-by: Paolo Valente --- block/bfq-iosched.c | 170 ++++++++++++++++++++++++-------------------- block/bfq-iosched.h | 12 ++-- 2 files changed, 101 insertions(+), 81 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 139b8f1ba439..bfdf954da5b7 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -404,10 +404,10 @@ void bic_set_bfqq(struct bfq_io_cq *bic, * we cancel the stable merge if * bic->stable_merge_bfqq == bfqq. */ - struct bfq_iocq_bfqq_data bfqq_data = bic->bfqq_data; + struct bfq_iocq_bfqq_data *bfqq_data = &bic->bfqq_data[actuator_idx]; bic->bfqq[is_sync][actuator_idx] = bfqq; - if (bfqq && bfqq_data.stable_merge_bfqq == bfqq) { + if (bfqq && bfqq_data->stable_merge_bfqq == bfqq) { /* * Actually, these same instructions are executed also * in bfq_setup_cooperator, in case of abort or actual @@ -416,9 +416,9 @@ void bic_set_bfqq(struct bfq_io_cq *bic, * did so, we would nest even more complexity in this * function. */ - bfq_put_stable_ref(bfqq_data.stable_merge_bfqq); + bfq_put_stable_ref(bfqq_data->stable_merge_bfqq); - bfqq_data.stable_merge_bfqq = NULL; + bfqq_data->stable_merge_bfqq = NULL; } } @@ -1175,40 +1175,43 @@ static void bfq_bfqq_resume_state(struct bfq_queue *bfqq, struct bfq_data *bfqd, struct bfq_io_cq *bic, bool bfq_already_existing) { - struct bfq_iocq_bfqq_data bfqq_data = bic->bfqq_data; unsigned int old_wr_coeff = 1; bool busy = bfq_already_existing && bfq_bfqq_busy(bfqq); + unsigned int a_idx = bfqq->actuator_idx; + struct bfq_iocq_bfqq_data *bfqq_data = &bic->bfqq_data[a_idx]; - if (bfqq_data.saved_has_short_ttime) + if (bfqq_data->saved_has_short_ttime) bfq_mark_bfqq_has_short_ttime(bfqq); else bfq_clear_bfqq_has_short_ttime(bfqq); - if (bfqq_data.saved_IO_bound) + if (bfqq_data->saved_IO_bound) bfq_mark_bfqq_IO_bound(bfqq); else bfq_clear_bfqq_IO_bound(bfqq); - bfqq->last_serv_time_ns = bfqq_data.saved_last_serv_time_ns; - bfqq->inject_limit = bfqq_data.saved_inject_limit; - bfqq->decrease_time_jif = bfqq_data.saved_decrease_time_jif; - - bfqq->entity.new_weight = bfqq_data.saved_weight; - bfqq->ttime = bfqq_data.saved_ttime; - bfqq->io_start_time = bfqq_data.saved_io_start_time; - bfqq->tot_idle_time = bfqq_data.saved_tot_idle_time; + bfqq->last_serv_time_ns = + bfqq_data->saved_last_serv_time_ns; + bfqq->inject_limit = bfqq_data->saved_inject_limit; + bfqq->decrease_time_jif = + bfqq_data->saved_decrease_time_jif; + bfqq->entity.new_weight = bfqq_data->saved_weight; + bfqq->ttime = bfqq_data->saved_ttime; + bfqq->io_start_time = bfqq_data->saved_io_start_time; + bfqq->tot_idle_time = bfqq_data->saved_tot_idle_time; /* * Restore weight coefficient only if low_latency is on */ if (bfqd->low_latency) { old_wr_coeff = bfqq->wr_coeff; - bfqq->wr_coeff = bfqq_data.saved_wr_coeff; + bfqq->wr_coeff = bfqq_data->saved_wr_coeff; } - bfqq->service_from_wr = bfqq_data.saved_service_from_wr; + bfqq->service_from_wr = bfqq_data->saved_service_from_wr; bfqq->wr_start_at_switch_to_srt = - bfqq_data.saved_wr_start_at_switch_to_srt; - bfqq->last_wr_start_finish = bfqq_data.saved_last_wr_start_finish; - bfqq->wr_cur_max_time = bfqq_data.saved_wr_cur_max_time; + bfqq_data->saved_wr_start_at_switch_to_srt; + bfqq->last_wr_start_finish = + bfqq_data->saved_last_wr_start_finish; + bfqq->wr_cur_max_time = bfqq_data->saved_wr_cur_max_time; if (bfqq->wr_coeff > 1 && (bfq_bfqq_in_large_burst(bfqq) || time_is_before_jiffies(bfqq->last_wr_start_finish + @@ -1827,6 +1830,16 @@ static bool bfq_bfqq_higher_class_or_weight(struct bfq_queue *bfqq, return bfqq_weight > in_serv_weight; } +/* get the index of the actuator that will serve bio */ +static unsigned int bfq_actuator_index(struct bfq_data *bfqd, struct bio *bio) +{ + /* + * Multi-actuator support not complete yet, so always return 0 + * for the moment. + */ + return 0; +} + static bool bfq_better_to_idle(struct bfq_queue *bfqq); static void bfq_bfqq_handle_idle_busy_switch(struct bfq_data *bfqd, @@ -1881,7 +1894,9 @@ static void bfq_bfqq_handle_idle_busy_switch(struct bfq_data *bfqd, wr_or_deserves_wr = bfqd->low_latency && (bfqq->wr_coeff > 1 || (bfq_bfqq_sync(bfqq) && - (bfqq->bic || RQ_BIC(rq)->bfqq_data.stably_merged) && + (bfqq->bic || + RQ_BIC(rq)->bfqq_data[bfq_actuator_index(bfqd, rq->bio)] + .stably_merged) && (*interactive || soft_rt))); /* @@ -2469,16 +2484,6 @@ static void bfq_remove_request(struct request_queue *q, } -/* get the index of the actuator that will serve bio */ -static unsigned int bfq_actuator_index(struct bfq_data *bfqd, struct bio *bio) -{ - /* - * Multi-actuator support not complete yet, so always return 0 - * for the moment. - */ - return 0; -} - static bool bfq_bio_merge(struct request_queue *q, struct bio *bio, unsigned int nr_segs) { @@ -2905,7 +2910,8 @@ bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq, void *io_struct, bool request, struct bfq_io_cq *bic) { struct bfq_queue *in_service_bfqq, *new_bfqq; - struct bfq_iocq_bfqq_data bfqq_data = bic->bfqq_data; + unsigned int a_idx = bfqq->actuator_idx; + struct bfq_iocq_bfqq_data *bfqq_data = &bic->bfqq_data[a_idx]; /* if a merge has already been setup, then proceed with that first */ if (bfqq->new_bfqq) @@ -2927,21 +2933,22 @@ bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq, * stable merging) also if bic is associated with a * sync queue, but this bfqq is async */ - if (bfq_bfqq_sync(bfqq) && bfqq_data.stable_merge_bfqq && + if (bfq_bfqq_sync(bfqq) && + bfqq_data->stable_merge_bfqq && !bfq_bfqq_just_created(bfqq) && time_is_before_jiffies(bfqq->split_time + msecs_to_jiffies(bfq_late_stable_merging)) && time_is_before_jiffies(bfqq->creation_time + msecs_to_jiffies(bfq_late_stable_merging))) { struct bfq_queue *stable_merge_bfqq = - bfqq_data.stable_merge_bfqq; + bfqq_data->stable_merge_bfqq; int proc_ref = min(bfqq_process_refs(bfqq), bfqq_process_refs(stable_merge_bfqq)); /* deschedule stable merge, because done or aborted here */ bfq_put_stable_ref(stable_merge_bfqq); - bfqq_data.stable_merge_bfqq = NULL; + bfqq_data->stable_merge_bfqq = NULL; if (!idling_boosts_thr_without_issues(bfqd, bfqq) && proc_ref > 0) { @@ -2950,10 +2957,11 @@ bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq, bfq_setup_merge(bfqq, stable_merge_bfqq); if (new_bfqq) { - bfqq_data.stably_merged = true; + bfqq_data->stably_merged = true; if (new_bfqq->bic) - new_bfqq->bic->bfqq_data.stably_merged = - true; + new_bfqq->bic->bfqq_data + [new_bfqq->actuator_idx] + .stably_merged = true; } return new_bfqq; } else @@ -3052,7 +3060,9 @@ bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq, static void bfq_bfqq_save_state(struct bfq_queue *bfqq) { struct bfq_io_cq *bic = bfqq->bic; - struct bfq_iocq_bfqq_data bfqq_data = bic->bfqq_data; + /* State must be saved for the right queue index. */ + unsigned int a_idx = bfqq->actuator_idx; + struct bfq_iocq_bfqq_data *bfqq_data = &bic->bfqq_data[a_idx]; /* * If !bfqq->bic, the queue is already shared or its requests @@ -3062,19 +3072,23 @@ static void bfq_bfqq_save_state(struct bfq_queue *bfqq) if (!bic) return; - bfqq_data.saved_last_serv_time_ns = bfqq->last_serv_time_ns; - bfqq_data.saved_inject_limit = bfqq->inject_limit; - bfqq_data.saved_decrease_time_jif = bfqq->decrease_time_jif; + bfqq_data->saved_last_serv_time_ns = + bfqq->last_serv_time_ns; + bfqq_data->saved_inject_limit = + bfqq->inject_limit; + bfqq_data->saved_decrease_time_jif = + bfqq->decrease_time_jif; - bfqq_data.saved_weight = bfqq->entity.orig_weight; - bfqq_data.saved_ttime = bfqq->ttime; - bfqq_data.saved_has_short_ttime = + bfqq_data->saved_weight = bfqq->entity.orig_weight; + bfqq_data->saved_ttime = bfqq->ttime; + bfqq_data->saved_has_short_ttime = bfq_bfqq_has_short_ttime(bfqq); - bfqq_data.saved_IO_bound = bfq_bfqq_IO_bound(bfqq); - bfqq_data.saved_io_start_time = bfqq->io_start_time; - bfqq_data.saved_tot_idle_time = bfqq->tot_idle_time; - bfqq_data.saved_in_large_burst = bfq_bfqq_in_large_burst(bfqq); - bfqq_data.was_in_burst_list = + bfqq_data->saved_IO_bound = bfq_bfqq_IO_bound(bfqq); + bfqq_data->saved_io_start_time = bfqq->io_start_time; + bfqq_data->saved_tot_idle_time = bfqq->tot_idle_time; + bfqq_data->saved_in_large_burst = + bfq_bfqq_in_large_burst(bfqq); + bfqq_data->was_in_burst_list = !hlist_unhashed(&bfqq->burst_list_node); if (unlikely(bfq_bfqq_just_created(bfqq) && @@ -3089,21 +3103,23 @@ static void bfq_bfqq_save_state(struct bfq_queue *bfqq) * to bfqq, so that to avoid that bfqq unjustly fails * to enjoy weight raising if split soon. */ - bfqq_data.saved_wr_coeff = bfqq->bfqd->bfq_wr_coeff; - bfqq_data.saved_wr_start_at_switch_to_srt = + bfqq_data->saved_wr_coeff = + bfqq->bfqd->bfq_wr_coeff; + bfqq_data->saved_wr_start_at_switch_to_srt = bfq_smallest_from_now(); - bfqq_data.saved_wr_cur_max_time = + bfqq_data->saved_wr_cur_max_time = bfq_wr_duration(bfqq->bfqd); - bfqq_data.saved_last_wr_start_finish = jiffies; + bfqq_data->saved_last_wr_start_finish = jiffies; } else { - bfqq_data.saved_wr_coeff = bfqq->wr_coeff; - bfqq_data.saved_wr_start_at_switch_to_srt = + bfqq_data->saved_wr_coeff = bfqq->wr_coeff; + bfqq_data->saved_wr_start_at_switch_to_srt = bfqq->wr_start_at_switch_to_srt; - bfqq_data.saved_service_from_wr = + bfqq_data->saved_service_from_wr = bfqq->service_from_wr; - bfqq_data.saved_last_wr_start_finish = + bfqq_data->saved_last_wr_start_finish = bfqq->last_wr_start_finish; - bfqq_data.saved_wr_cur_max_time = bfqq->wr_cur_max_time; + bfqq_data->saved_wr_cur_max_time = + bfqq->wr_cur_max_time; } } @@ -5425,7 +5441,7 @@ static void bfq_exit_icq(struct io_cq *icq) unsigned long flags; unsigned int act_idx; unsigned int num_actuators; - struct bfq_iocq_bfqq_data bfqq_data = bic->bfqq_data; + struct bfq_iocq_bfqq_data *bfqq_data = bic->bfqq_data; /* * bfqd is NULL if scheduler already exited, and in that case @@ -5445,10 +5461,10 @@ static void bfq_exit_icq(struct io_cq *icq) num_actuators = BFQ_MAX_ACTUATORS; } - if (bfqq_data.stable_merge_bfqq) - bfq_put_stable_ref(bfqq_data.stable_merge_bfqq); - for (act_idx = 0; act_idx < num_actuators; act_idx++) { + if (bfqq_data[act_idx].stable_merge_bfqq) + bfq_put_stable_ref(bfqq_data[act_idx].stable_merge_bfqq); + bfq_exit_icq_bfqq(bic, true, act_idx); bfq_exit_icq_bfqq(bic, false, act_idx); } @@ -5635,16 +5651,16 @@ bfq_do_early_stable_merge(struct bfq_data *bfqd, struct bfq_queue *bfqq, struct bfq_io_cq *bic, struct bfq_queue *last_bfqq_created) { + unsigned int a_idx = last_bfqq_created->actuator_idx; struct bfq_queue *new_bfqq = bfq_setup_merge(bfqq, last_bfqq_created); - struct bfq_iocq_bfqq_data bfqq_data = bic->bfqq_data; if (!new_bfqq) return bfqq; if (new_bfqq->bic) - new_bfqq->bic->bfqq_data.stably_merged = true; - bfqq_data.stably_merged = true; + new_bfqq->bic->bfqq_data[a_idx].stably_merged = true; + bic->bfqq_data[a_idx].stably_merged = true; /* * Reusing merge functions. This implies that @@ -5713,7 +5729,6 @@ static struct bfq_queue *bfq_do_or_sched_stable_merge(struct bfq_data *bfqd, &bfqd->last_bfqq_created; struct bfq_queue *last_bfqq_created = *source_bfqq; - struct bfq_iocq_bfqq_data bfqq_data = bic->bfqq_data; /* * If last_bfqq_created has not been set yet, then init it. If @@ -5775,7 +5790,8 @@ static struct bfq_queue *bfq_do_or_sched_stable_merge(struct bfq_data *bfqd, /* * Record the bfqq to merge to. */ - bfqq_data.stable_merge_bfqq = last_bfqq_created; + bic->bfqq_data[last_bfqq_created->actuator_idx].stable_merge_bfqq = + last_bfqq_created; } } @@ -6696,7 +6712,7 @@ static struct bfq_queue *bfq_get_bfqq_handle_split(struct bfq_data *bfqd, { unsigned int act_idx = bfq_actuator_index(bfqd, bio); struct bfq_queue *bfqq = bic_to_bfqq(bic, is_sync, act_idx); - struct bfq_iocq_bfqq_data bfqq_data = bic->bfqq_data; + struct bfq_iocq_bfqq_data *bfqq_data = &bic->bfqq_data[act_idx]; if (likely(bfqq && bfqq != &bfqd->oom_bfqq)) return bfqq; @@ -6710,12 +6726,13 @@ static struct bfq_queue *bfq_get_bfqq_handle_split(struct bfq_data *bfqd, bic_set_bfqq(bic, bfqq, is_sync, act_idx); if (split && is_sync) { - if ((bfqq_data.was_in_burst_list && bfqd->large_burst) || - bfqq_data.saved_in_large_burst) + if ((bfqq_data->was_in_burst_list && + bfqd->large_burst) || + bfqq_data->saved_in_large_burst) bfq_mark_bfqq_in_large_burst(bfqq); else { bfq_clear_bfqq_in_large_burst(bfqq); - if (bfqq_data.was_in_burst_list) + if (bfqq_data->was_in_burst_list) /* * If bfqq was in the current * burst list before being @@ -6804,7 +6821,7 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) struct bfq_queue *bfqq; bool new_queue = false; bool bfqq_already_existing = false, split = false; - struct bfq_iocq_bfqq_data bfqq_data; + unsigned int a_idx = bfq_actuator_index(bfqd, bio); if (unlikely(!rq->elv.icq)) return NULL; @@ -6828,17 +6845,16 @@ static struct bfq_queue *bfq_init_rq(struct request *rq) bfqq = bfq_get_bfqq_handle_split(bfqd, bic, bio, false, is_sync, &new_queue); - bfqq_data = bic->bfqq_data; - if (likely(!new_queue)) { /* If the queue was seeky for too long, break it apart. */ if (bfq_bfqq_coop(bfqq) && bfq_bfqq_split_coop(bfqq) && - !bfqq_data.stably_merged) { + !bic->bfqq_data[a_idx].stably_merged) { struct bfq_queue *old_bfqq = bfqq; /* Update bic before losing reference to bfqq */ if (bfq_bfqq_in_large_burst(bfqq)) - bfqq_data.saved_in_large_burst = true; + bic->bfqq_data[a_idx].saved_in_large_burst = + true; bfqq = bfq_split_bfqq(bic, bfqq); split = true; diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index f2e8ab91951c..e27897d66a0f 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -416,7 +416,7 @@ struct bfq_queue { struct bfq_iocq_bfqq_data { /* * Snapshot of the has_short_time flag before merging; taken - * to remember its value while the queue is merged, so as to + * to remember its values while the queue is merged, so as to * be able to restore it in case of split. */ bool saved_has_short_ttime; @@ -430,7 +430,7 @@ struct bfq_iocq_bfqq_data { u64 saved_tot_idle_time; /* - * Same purpose as the previous fields for the value of the + * Same purpose as the previous fields for the values of the * field keeping the queue's belonging to a large burst */ bool saved_in_large_burst; @@ -493,8 +493,12 @@ struct bfq_io_cq { uint64_t blkcg_serial_nr; /* the current blkcg serial */ #endif - /* persistent data for associated synchronous process queue */ - struct bfq_iocq_bfqq_data bfqq_data; + /* + * Persistent data for associated synchronous process queues + * (one queue per actuator, see field bfqq above). In + * particular, each of these queues may undergo a merge. + */ + struct bfq_iocq_bfqq_data bfqq_data[BFQ_MAX_ACTUATORS]; unsigned int requests; /* Number of requests this process has in flight */ };