From patchwork Wed Jun 10 17:29:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Garry X-Patchwork-Id: 11598511 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2381614E3 for ; Wed, 10 Jun 2020 17:33:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1206A20734 for ; Wed, 10 Jun 2020 17:33:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726924AbgFJRdf (ORCPT ); Wed, 10 Jun 2020 13:33:35 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:5807 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726393AbgFJRde (ORCPT ); Wed, 10 Jun 2020 13:33:34 -0400 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 023A14CF78F34D365122; Thu, 11 Jun 2020 01:33:27 +0800 (CST) Received: from localhost.localdomain (10.69.192.58) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.487.0; Thu, 11 Jun 2020 01:33:19 +0800 From: John Garry To: , , , , , , , , , , CC: , , , , , John Garry Subject: [PATCH RFC v7 05/12] blk-mq: Record nr_active_requests per queue for when using shared sbitmap Date: Thu, 11 Jun 2020 01:29:12 +0800 Message-ID: <1591810159-240929-6-git-send-email-john.garry@huawei.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1591810159-240929-1-git-send-email-john.garry@huawei.com> References: <1591810159-240929-1-git-send-email-john.garry@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.69.192.58] X-CFilter-Loop: Reflected Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The per-hctx nr_active value can no longer be used to fairly assign a share of tag depth per request queue for when using a shared sbitmap, as it does not consider that the tags are shared tags over all hctx's. For this case, record the nr_active_requests per request_queue, and make the judgment based on that value. Also introduce a debugfs version of per-hctx blk_mq_debugfs_attr, omitting hctx_active_show() (as blk_mq_hw_ctx.nr_active is no longer maintained for the case of shared sbitmap) and other entries which we can add which would be revised specifically for when using a shared sbitmap. Co-developed-with: Kashyap Desai Signed-off-by: John Garry --- block/blk-core.c | 2 ++ block/blk-mq-debugfs.c | 23 ++++++++++++++++++++++- block/blk-mq-tag.c | 10 ++++++---- block/blk-mq.c | 6 +++--- block/blk-mq.h | 28 +++++++++++++++++++++++++++- include/linux/blkdev.h | 2 ++ 6 files changed, 62 insertions(+), 9 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 03252af8c82c..c622453c1363 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -529,6 +529,8 @@ struct request_queue *__blk_alloc_queue(int node_id) q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK; q->node = node_id; + atomic_set(&q->nr_active_requests_shared_sbitmap, 0); + timer_setup(&q->backing_dev_info->laptop_mode_wb_timer, laptop_mode_timer_fn, 0); timer_setup(&q->timeout, blk_rq_timed_out_timer, 0); diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index a400b6698dff..0fa3af41ab65 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -796,6 +796,23 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { {}, }; +static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_shared_sbitmap_attrs[] = { + {"state", 0400, hctx_state_show}, + {"flags", 0400, hctx_flags_show}, + {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops}, + {"busy", 0400, hctx_busy_show}, + {"ctx_map", 0400, hctx_ctx_map_show}, + {"sched_tags", 0400, hctx_sched_tags_show}, + {"sched_tags_bitmap", 0400, hctx_sched_tags_bitmap_show}, + {"io_poll", 0600, hctx_io_poll_show, hctx_io_poll_write}, + {"dispatched", 0600, hctx_dispatched_show, hctx_dispatched_write}, + {"queued", 0600, hctx_queued_show, hctx_queued_write}, + {"run", 0600, hctx_run_show, hctx_run_write}, + {"active", 0400, hctx_active_show}, + {"dispatch_busy", 0400, hctx_dispatch_busy_show}, + {} +}; + static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { {"default_rq_list", 0400, .seq_ops = &ctx_default_rq_list_seq_ops}, {"read_rq_list", 0400, .seq_ops = &ctx_read_rq_list_seq_ops}, @@ -878,13 +895,17 @@ void blk_mq_debugfs_register_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx) { struct blk_mq_ctx *ctx; + struct blk_mq_tag_set *set = q->tag_set; char name[20]; int i; snprintf(name, sizeof(name), "hctx%u", hctx->queue_num); hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir); - debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs); + if (blk_mq_is_sbitmap_shared(set)) + debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_shared_sbitmap_attrs); + else + debugfs_create_files(hctx->debugfs_dir, hctx, blk_mq_debugfs_hctx_attrs); hctx_for_each_ctx(hctx, ctx, i) blk_mq_debugfs_register_ctx(hctx, ctx); diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 92843e3e1a2a..7db16e49f6f6 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -60,9 +60,11 @@ void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) * For shared tag users, we track the number of currently active users * and attempt to provide a fair share of the tag depth for each of them. */ -static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, +static inline bool hctx_may_queue(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt) { + struct blk_mq_hw_ctx *hctx = data->hctx; + struct request_queue *q = data->q; unsigned int depth, users; if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) @@ -84,15 +86,15 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, * Allow at least some tags */ depth = max((bt->sb.depth + users - 1) / users, 4U); - return atomic_read(&hctx->nr_active) < depth; + return __blk_mq_active_requests(hctx, q) < depth; } static int __blk_mq_get_tag(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt) { if (!(data->flags & BLK_MQ_REQ_INTERNAL) && - !hctx_may_queue(data->hctx, bt)) - return BLK_MQ_NO_TAG; + !hctx_may_queue(data, bt)) + return -1; if (data->shallow_depth) return __sbitmap_queue_get_shallow(bt, data->shallow_depth); else diff --git a/block/blk-mq.c b/block/blk-mq.c index 77120dd4e4d5..0f7e062a1665 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -283,7 +283,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, } else { if (data->hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) { rq_flags = RQF_MQ_INFLIGHT; - atomic_inc(&data->hctx->nr_active); + __blk_mq_inc_active_requests(data->hctx, data->q); } rq->tag = tag; rq->internal_tag = BLK_MQ_NO_TAG; @@ -527,7 +527,7 @@ void blk_mq_free_request(struct request *rq) ctx->rq_completed[rq_is_sync(rq)]++; if (rq->rq_flags & RQF_MQ_INFLIGHT) - atomic_dec(&hctx->nr_active); + __blk_mq_dec_active_requests(hctx, q); if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq))) laptop_io_completion(q->backing_dev_info); @@ -1073,7 +1073,7 @@ bool blk_mq_get_driver_tag(struct request *rq) if (rq->tag >= 0) { if (shared) { rq->rq_flags |= RQF_MQ_INFLIGHT; - atomic_inc(&data.hctx->nr_active); + __blk_mq_inc_active_requests(rq->mq_hctx, rq->q); } data.hctx->tags->rqs[rq->tag] = rq; } diff --git a/block/blk-mq.h b/block/blk-mq.h index 1a283c707215..9c1e612c2298 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -202,6 +202,32 @@ static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx) return true; } +static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx, + struct request_queue *q) +{ + if (blk_mq_is_sbitmap_shared(q->tag_set)) + atomic_inc(&q->nr_active_requests_shared_sbitmap); + else + atomic_inc(&hctx->nr_active); +} + +static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx, + struct request_queue *q) +{ + if (blk_mq_is_sbitmap_shared(q->tag_set)) + atomic_dec(&q->nr_active_requests_shared_sbitmap); + else + atomic_dec(&hctx->nr_active); +} + +static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx, + struct request_queue *q) +{ + if (blk_mq_is_sbitmap_shared(q->tag_set)) + return atomic_read(&q->nr_active_requests_shared_sbitmap); + return atomic_read(&hctx->nr_active); +} + static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq) { @@ -210,7 +236,7 @@ static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, if (rq->rq_flags & RQF_MQ_INFLIGHT) { rq->rq_flags &= ~RQF_MQ_INFLIGHT; - atomic_dec(&hctx->nr_active); + __blk_mq_dec_active_requests(hctx, rq->q); } } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 8fd900998b4e..c536278bec9e 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -488,6 +488,8 @@ struct request_queue { struct timer_list timeout; struct work_struct timeout_work; + atomic_t nr_active_requests_shared_sbitmap; + struct list_head icq_list; #ifdef CONFIG_BLK_CGROUP DECLARE_BITMAP (blkcg_pols, BLKCG_MAX_POLS);