From patchwork Thu Aug 24 14:43:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengming Zhou X-Patchwork-Id: 13364312 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DDC8CC6FA8F for ; Thu, 24 Aug 2023 14:46:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241739AbjHXOpc (ORCPT ); Thu, 24 Aug 2023 10:45:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241733AbjHXOpL (ORCPT ); Thu, 24 Aug 2023 10:45:11 -0400 Received: from out-39.mta1.migadu.com (out-39.mta1.migadu.com [IPv6:2001:41d0:203:375::27]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F68F1BC5 for ; Thu, 24 Aug 2023 07:45:09 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1692888307; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZPF+c1DJ7XmvhtLIn8XJOXXiqYrgAJHZCAQvWuMIHRQ=; b=PtBO8GhDb7ozEtU9kP2iVRjbUhhPDrVqhXJ12tWghz4MV8Z/vLY50fEpBZ7YsatVtjEQMW fQBcJ0VvKSXqaNK2AYY/nPNI2Ych8r8jnsvEavHhFq3vkhhF7eQc24BK8DJbw4dHLUbTm7 tR47+vDLlad1Vrwe7GOF2+A7+qMCfLs= From: chengming.zhou@linux.dev To: axboe@kernel.dk, hch@lst.de, ming.lei@redhat.com, bvanassche@acm.org, kbusch@kernel.org Cc: mst@redhat.com, sagi@grimberg.me, damien.lemoal@opensource.wdc.com, kch@nvidia.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, zhouchengming@bytedance.com Subject: [PATCH 1/6] blk-mq: account active requests when get driver tag Date: Thu, 24 Aug 2023 22:43:58 +0800 Message-ID: <20230824144403.2135739-2-chengming.zhou@linux.dev> In-Reply-To: <20230824144403.2135739-1-chengming.zhou@linux.dev> References: <20230824144403.2135739-1-chengming.zhou@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Chengming Zhou There is a limit that batched queue_rqs() can't work on shared tags queue, since the account of active requests can't be done there. Now we account the active requests only in blk_mq_get_driver_tag(), which is not the time we get driver tag actually (with none elevator). To support batched queue_rqs() on shared tags queue, we move the account of active requests to where we get the driver tag: 1. none elevator: blk_mq_get_tags() and blk_mq_get_tag() 2. other elevator: __blk_mq_alloc_driver_tag() This is clearer and match with the unaccount side, which just happen when we put the driver tag. The other good point is that we don't need RQF_MQ_INFLIGHT trick anymore, which used to avoid double account of flush request. Now we only account when actually get the driver tag, so all is good. We will remove RQF_MQ_INFLIGHT in the next patch. Signed-off-by: Chengming Zhou --- block/blk-mq.c | 33 +++++++++++------------------ block/blk-mq.h | 56 ++++++++++++++++++++++++++++++++++++-------------- 2 files changed, 53 insertions(+), 36 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index ec922c6bccbe..bcdb750ef575 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -426,6 +426,8 @@ __blk_mq_alloc_requests_batch(struct blk_mq_alloc_data *data) rq_list_add(data->cached_rq, rq); nr++; } + if (!(data->rq_flags & RQF_SCHED_TAGS)) + blk_mq_add_active_requests(data->hctx, nr); /* caller already holds a reference, add for remainder */ percpu_ref_get_many(&data->q->q_usage_counter, nr - 1); data->nr_tags -= nr; @@ -510,6 +512,8 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) goto retry; } + if (!(data->rq_flags & RQF_SCHED_TAGS)) + blk_mq_inc_active_requests(data->hctx); rq = blk_mq_rq_ctx_init(data, blk_mq_tags_from_data(data), tag); blk_mq_rq_time_init(rq, alloc_time_ns); return rq; @@ -669,6 +673,8 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, tag = blk_mq_get_tag(&data); if (tag == BLK_MQ_NO_TAG) goto out_queue_exit; + if (!(data.rq_flags & RQF_SCHED_TAGS)) + blk_mq_inc_active_requests(data.hctx); rq = blk_mq_rq_ctx_init(&data, blk_mq_tags_from_data(&data), tag); blk_mq_rq_time_init(rq, alloc_time_ns); rq->__data_len = 0; @@ -708,11 +714,10 @@ static void __blk_mq_free_request(struct request *rq) blk_pm_mark_last_busy(rq); rq->mq_hctx = NULL; - if (rq->rq_flags & RQF_MQ_INFLIGHT) - __blk_mq_dec_active_requests(hctx); - - if (rq->tag != BLK_MQ_NO_TAG) + if (rq->tag != BLK_MQ_NO_TAG) { + blk_mq_dec_active_requests(hctx); blk_mq_put_tag(hctx->tags, ctx, rq->tag); + } if (sched_tag != BLK_MQ_NO_TAG) blk_mq_put_tag(hctx->sched_tags, ctx, sched_tag); blk_mq_sched_restart(hctx); @@ -1065,8 +1070,7 @@ static inline void blk_mq_flush_tag_batch(struct blk_mq_hw_ctx *hctx, * All requests should have been marked as RQF_MQ_INFLIGHT, so * update hctx->nr_active in batch */ - if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) - __blk_mq_sub_active_requests(hctx, nr_tags); + blk_mq_sub_active_requests(hctx, nr_tags); blk_mq_put_tags(hctx->tags, tag_array, nr_tags); percpu_ref_put_many(&q->q_usage_counter, nr_tags); @@ -1748,7 +1752,7 @@ struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, return data.rq; } -static bool __blk_mq_alloc_driver_tag(struct request *rq) +bool __blk_mq_alloc_driver_tag(struct request *rq) { struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags; unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags; @@ -1769,20 +1773,7 @@ static bool __blk_mq_alloc_driver_tag(struct request *rq) return false; rq->tag = tag + tag_offset; - return true; -} - -bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq) -{ - if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq)) - return false; - - if ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) && - !(rq->rq_flags & RQF_MQ_INFLIGHT)) { - rq->rq_flags |= RQF_MQ_INFLIGHT; - __blk_mq_inc_active_requests(hctx); - } - hctx->tags->rqs[rq->tag] = rq; + blk_mq_inc_active_requests(rq->mq_hctx); return true; } diff --git a/block/blk-mq.h b/block/blk-mq.h index 1743857e0b01..560a76df290a 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -271,12 +271,18 @@ static inline int blk_mq_get_rq_budget_token(struct request *rq) return -1; } -static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) +static inline void __blk_mq_add_active_requests(struct blk_mq_hw_ctx *hctx, + int val) { if (blk_mq_is_shared_tags(hctx->flags)) - atomic_inc(&hctx->queue->nr_active_requests_shared_tags); + atomic_add(val, &hctx->queue->nr_active_requests_shared_tags); else - atomic_inc(&hctx->nr_active); + atomic_add(val, &hctx->nr_active); +} + +static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) +{ + __blk_mq_add_active_requests(hctx, 1); } static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx, @@ -293,6 +299,32 @@ static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx) __blk_mq_sub_active_requests(hctx, 1); } +static inline void blk_mq_add_active_requests(struct blk_mq_hw_ctx *hctx, + int val) +{ + if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) + __blk_mq_add_active_requests(hctx, val); +} + +static inline void blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx) +{ + if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) + __blk_mq_inc_active_requests(hctx); +} + +static inline void blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx, + int val) +{ + if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) + __blk_mq_sub_active_requests(hctx, val); +} + +static inline void blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx) +{ + if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) + __blk_mq_dec_active_requests(hctx); +} + static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx) { if (blk_mq_is_shared_tags(hctx->flags)) @@ -302,13 +334,9 @@ static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx) static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq) { + blk_mq_dec_active_requests(hctx); blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag); rq->tag = BLK_MQ_NO_TAG; - - if (rq->rq_flags & RQF_MQ_INFLIGHT) { - rq->rq_flags &= ~RQF_MQ_INFLIGHT; - __blk_mq_dec_active_requests(hctx); - } } static inline void blk_mq_put_driver_tag(struct request *rq) @@ -319,19 +347,17 @@ static inline void blk_mq_put_driver_tag(struct request *rq) __blk_mq_put_driver_tag(rq->mq_hctx, rq); } -bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq); +bool __blk_mq_alloc_driver_tag(struct request *rq); static inline bool blk_mq_get_driver_tag(struct request *rq) { struct blk_mq_hw_ctx *hctx = rq->mq_hctx; - if (rq->tag != BLK_MQ_NO_TAG && - !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { - hctx->tags->rqs[rq->tag] = rq; - return true; - } + if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq)) + return false; - return __blk_mq_get_driver_tag(hctx, rq); + hctx->tags->rqs[rq->tag] = rq; + return true; } static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)