From patchwork Fri Jul 7 09:37:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengming Zhou X-Patchwork-Id: 13304634 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 3E81EEB64DA for ; Fri, 7 Jul 2023 09:39:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231779AbjGGJjI (ORCPT ); Fri, 7 Jul 2023 05:39:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232607AbjGGJjG (ORCPT ); Fri, 7 Jul 2023 05:39:06 -0400 Received: from out-13.mta0.migadu.com (out-13.mta0.migadu.com [IPv6:2001:41d0:1004:224b::d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42EEE2106 for ; Fri, 7 Jul 2023 02:39:05 -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=1688722743; 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=GNQffBpvwsnQY1EH1HZ//XhBWHXASFg3WNRxajHHe/k=; b=fp2imDnjRIdA+x9yfGUVEx9Y742YG+UA7+IZVdK3KPoej92hyEUCPCVKDxZqMwCTvu5NL3 Zu3ekiHzUtwtu4U58i2kJhJPALPiW46XLqCLscWSUWuLbKxiG7aAHJ5ClJ55+Uferx91IR VfmYznnkwG3bzfKDSBnmb11Vz7eBwwI= From: chengming.zhou@linux.dev To: axboe@kernel.dk, ming.lei@redhat.com, hch@lst.de, tj@kernel.org Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, zhouchengming@bytedance.com Subject: [PATCH v3 1/4] blk-mq: delete unused completion_data in struct request Date: Fri, 7 Jul 2023 17:37:19 +0800 Message-ID: <20230707093722.1338589-2-chengming.zhou@linux.dev> In-Reply-To: <20230707093722.1338589-1-chengming.zhou@linux.dev> References: <20230707093722.1338589-1-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 After global search, I found "completion_data" in struct request is not used anywhere, so just clean it up by the way. Signed-off-by: Chengming Zhou Reviewed-by: Christoph Hellwig Reviewed-by: Ming Lei --- include/linux/blk-mq.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index f401067ac03a..0a1c404e6c7a 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -158,13 +158,11 @@ struct request { /* * The rb_node is only used inside the io scheduler, requests - * are pruned when moved to the dispatch queue. So let the - * completion_data share space with the rb_node. + * are pruned when moved to the dispatch queue. */ union { struct rb_node rb_node; /* sort/lookup */ struct bio_vec special_vec; - void *completion_data; }; /* From patchwork Fri Jul 7 09:37:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengming Zhou X-Patchwork-Id: 13304635 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 59EAEC0015E for ; Fri, 7 Jul 2023 09:39:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232752AbjGGJjN (ORCPT ); Fri, 7 Jul 2023 05:39:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232139AbjGGJjJ (ORCPT ); Fri, 7 Jul 2023 05:39:09 -0400 Received: from out-32.mta0.migadu.com (out-32.mta0.migadu.com [91.218.175.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0C672105 for ; Fri, 7 Jul 2023 02:39:08 -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=1688722747; 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=QGerpK1V1ctRjZC2+PWM/5ULJ+kFtEXJRRHXssQgmz0=; b=tp5iOy0v8KgRa4hlqo8i924ZQp+iuFTBITRyHheniNvm5f7NmrOMXW4w4tbs8LhaNFMRTr u3lRyyu1yPeaQba0mTC5uet5FJCdOQ9dHpoIkFx8chDvgjoQzwIsBEavz0pb5IPAvA0Lrr dV8vx/Z4HH10KBrOU8IKjaxyHix3Ppk= From: chengming.zhou@linux.dev To: axboe@kernel.dk, ming.lei@redhat.com, hch@lst.de, tj@kernel.org Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, zhouchengming@bytedance.com Subject: [PATCH v3 2/4] blk-mq: use percpu csd to remote complete instead of per-rq csd Date: Fri, 7 Jul 2023 17:37:20 +0800 Message-ID: <20230707093722.1338589-3-chengming.zhou@linux.dev> In-Reply-To: <20230707093722.1338589-1-chengming.zhou@linux.dev> References: <20230707093722.1338589-1-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 If request need to be completed remotely, we insert it into percpu llist, and smp_call_function_single_async() if llist is empty previously. We don't need to use per-rq csd, percpu csd is enough. And the size of struct request is decreased by 24 bytes. This way is cleaner, and looks correct, given block softirq is guaranteed to be scheduled to consume the list if one new request is added to this percpu list, either smp_call_function_single_async() returns -EBUSY or 0. Signed-off-by: Chengming Zhou Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig --- v3: - Remove the list and csd variables as they are only used once, as suggested by Christoph Hellwig. v2: - Change to use call_single_data_t, which avoid to use 2 cache lines for 1 csd, as suggested by Ming Lei. - Improve the commit log, the explanation is copied from Ming Lei. --- block/blk-mq.c | 12 ++++++------ include/linux/blk-mq.h | 5 +---- 2 files changed, 7 insertions(+), 10 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index decb6ab2d508..7d013588077a 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -43,6 +43,7 @@ #include "blk-ioprio.h" static DEFINE_PER_CPU(struct llist_head, blk_cpu_done); +static DEFINE_PER_CPU(call_single_data_t, blk_cpu_csd); static void blk_mq_insert_request(struct request *rq, blk_insert_t flags); static void blk_mq_request_bypass_insert(struct request *rq, @@ -1154,15 +1155,11 @@ static inline bool blk_mq_complete_need_ipi(struct request *rq) static void blk_mq_complete_send_ipi(struct request *rq) { - struct llist_head *list; unsigned int cpu; cpu = rq->mq_ctx->cpu; - list = &per_cpu(blk_cpu_done, cpu); - if (llist_add(&rq->ipi_list, list)) { - INIT_CSD(&rq->csd, __blk_mq_complete_request_remote, rq); - smp_call_function_single_async(cpu, &rq->csd); - } + if (llist_add(&rq->ipi_list, &per_cpu(blk_cpu_done, cpu))) + smp_call_function_single_async(cpu, &per_cpu(blk_cpu_csd, cpu)); } static void blk_mq_raise_softirq(struct request *rq) @@ -4796,6 +4793,9 @@ static int __init blk_mq_init(void) for_each_possible_cpu(i) init_llist_head(&per_cpu(blk_cpu_done, i)); + for_each_possible_cpu(i) + INIT_CSD(&per_cpu(blk_cpu_csd, i), + __blk_mq_complete_request_remote, NULL); open_softirq(BLOCK_SOFTIRQ, blk_done_softirq); cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD, diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 0a1c404e6c7a..34d400171b3e 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -180,10 +180,7 @@ struct request { rq_end_io_fn *saved_end_io; } flush; - union { - struct __call_single_data csd; - u64 fifo_time; - }; + u64 fifo_time; /* * completion callback. From patchwork Fri Jul 7 09:37:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengming Zhou X-Patchwork-Id: 13304636 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 A2744C0015E for ; Fri, 7 Jul 2023 09:39:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232775AbjGGJjR (ORCPT ); Fri, 7 Jul 2023 05:39:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232619AbjGGJjQ (ORCPT ); Fri, 7 Jul 2023 05:39:16 -0400 Received: from out-62.mta0.migadu.com (out-62.mta0.migadu.com [IPv6:2001:41d0:1004:224b::3e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01E982105 for ; Fri, 7 Jul 2023 02:39:12 -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=1688722750; 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=wQHKRGRlsyTFKhwuew2Tx6TZYS0qTNQ4+BQ+yG3MTOA=; b=J9GTLIgtqXNmw32UYmkN+AmXUu2QT9b46HjAnrAm16JK3khPLzs/wyFmc80OM5ua/1Vfpt O8swy4FMJbbbViRW7/evIiozhfHZWBiwf3B+ODkDRccMKbLUyV7+w8DAT90Mcd79ZE9eTj tpzJ+zJA3AG5ELF1BpJkrTo/NgnGgio= From: chengming.zhou@linux.dev To: axboe@kernel.dk, ming.lei@redhat.com, hch@lst.de, tj@kernel.org Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, zhouchengming@bytedance.com Subject: [PATCH v3 3/4] blk-flush: count inflight flush_data requests Date: Fri, 7 Jul 2023 17:37:21 +0800 Message-ID: <20230707093722.1338589-4-chengming.zhou@linux.dev> In-Reply-To: <20230707093722.1338589-1-chengming.zhou@linux.dev> References: <20230707093722.1338589-1-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 The flush state machine use a double list to link all inflight flush_data requests, to avoid issuing separate post-flushes for these flush_data requests which shared PREFLUSH. So we can't reuse rq->queuelist, this is why we need rq->flush.list In preparation of the next patch that reuse rq->queuelist for flush state machine, we change the double linked list to unsigned long counter, which count all inflight flush_data requests. This is ok since we only need to know if there is any inflight flush_data request, so unsigned long counter is good. Signed-off-by: Chengming Zhou Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig --- block/blk-flush.c | 9 +++++---- block/blk.h | 5 ++--- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/block/blk-flush.c b/block/blk-flush.c index dba392cf22be..bb7adfc2a5da 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -187,7 +187,8 @@ static void blk_flush_complete_seq(struct request *rq, break; case REQ_FSEQ_DATA: - list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); + list_del_init(&rq->flush.list); + fq->flush_data_in_flight++; spin_lock(&q->requeue_lock); list_add_tail(&rq->queuelist, &q->flush_list); spin_unlock(&q->requeue_lock); @@ -299,7 +300,7 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq, return; /* C2 and C3 */ - if (!list_empty(&fq->flush_data_in_flight) && + if (fq->flush_data_in_flight && time_before(jiffies, fq->flush_pending_since + FLUSH_PENDING_TIMEOUT)) return; @@ -374,6 +375,7 @@ static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq, * the comment in flush_end_io(). */ spin_lock_irqsave(&fq->mq_flush_lock, flags); + fq->flush_data_in_flight--; blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error); spin_unlock_irqrestore(&fq->mq_flush_lock, flags); @@ -445,7 +447,7 @@ bool blk_insert_flush(struct request *rq) blk_rq_init_flush(rq); rq->flush.seq |= REQ_FSEQ_POSTFLUSH; spin_lock_irq(&fq->mq_flush_lock); - list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); + fq->flush_data_in_flight++; spin_unlock_irq(&fq->mq_flush_lock); return false; default: @@ -496,7 +498,6 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, INIT_LIST_HEAD(&fq->flush_queue[0]); INIT_LIST_HEAD(&fq->flush_queue[1]); - INIT_LIST_HEAD(&fq->flush_data_in_flight); return fq; diff --git a/block/blk.h b/block/blk.h index 608c5dcc516b..686712e13835 100644 --- a/block/blk.h +++ b/block/blk.h @@ -15,15 +15,14 @@ struct elevator_type; extern struct dentry *blk_debugfs_root; struct blk_flush_queue { + spinlock_t mq_flush_lock; unsigned int flush_pending_idx:1; unsigned int flush_running_idx:1; blk_status_t rq_status; unsigned long flush_pending_since; struct list_head flush_queue[2]; - struct list_head flush_data_in_flight; + unsigned long flush_data_in_flight; struct request *flush_rq; - - spinlock_t mq_flush_lock; }; bool is_flush_rq(struct request *req); From patchwork Fri Jul 7 09:37:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chengming Zhou X-Patchwork-Id: 13304637 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 AA74AEB64DA for ; Fri, 7 Jul 2023 09:39:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232716AbjGGJje (ORCPT ); Fri, 7 Jul 2023 05:39:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232804AbjGGJjV (ORCPT ); Fri, 7 Jul 2023 05:39:21 -0400 Received: from out-1.mta0.migadu.com (out-1.mta0.migadu.com [91.218.175.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75C2E2117 for ; Fri, 7 Jul 2023 02:39:16 -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=1688722754; 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=znByHfzQSpvrPQaReH7yflCmK5TREu8Z0tH8P3jgNog=; b=k7qzuLrFyLTHZjTplLwK1pIMWbb8ID0RsNUs4Ol1S8PtEC8M5suueKCd3IbrWN5ymFPn7L nJb+qDCU2VhjmBkz7x9+mo5G5TP4+RPaHNpqlbB807FYEBzpT5x7zerC5w8JMfDl0HLH20 ZkBK7AQ8c03WwQMbsn4KP4k8L1ZAzrI= From: chengming.zhou@linux.dev To: axboe@kernel.dk, ming.lei@redhat.com, hch@lst.de, tj@kernel.org Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, zhouchengming@bytedance.com Subject: [PATCH v3 4/4] blk-flush: reuse rq queuelist in flush state machine Date: Fri, 7 Jul 2023 17:37:22 +0800 Message-ID: <20230707093722.1338589-5-chengming.zhou@linux.dev> In-Reply-To: <20230707093722.1338589-1-chengming.zhou@linux.dev> References: <20230707093722.1338589-1-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 Since we don't need to maintain inflight flush_data requests list anymore, we can reuse rq->queuelist for flush pending list. Note in mq_flush_data_end_io(), we need to re-initialize rq->queuelist before reusing it in the state machine when end, since the rq->rq_next also reuse it, may have corrupted rq->queuelist by the driver. This patch decrease the size of struct request by 16 bytes. Signed-off-by: Chengming Zhou Reviewed-by: Christoph Hellwig Reviewed-by: Ming Lei --- v3: - fix a bug report of blktests nvme/012, we need to re-initialize rq->queuelist before reusing it in the state machine when end. Because rq->rq_next reuse may have corrupted it. Thanks Ming Lei. --- block/blk-flush.c | 17 ++++++++++------- include/linux/blk-mq.h | 1 - 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/block/blk-flush.c b/block/blk-flush.c index bb7adfc2a5da..4826d2d61a23 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -183,14 +183,13 @@ static void blk_flush_complete_seq(struct request *rq, /* queue for flush */ if (list_empty(pending)) fq->flush_pending_since = jiffies; - list_move_tail(&rq->flush.list, pending); + list_move_tail(&rq->queuelist, pending); break; case REQ_FSEQ_DATA: - list_del_init(&rq->flush.list); fq->flush_data_in_flight++; spin_lock(&q->requeue_lock); - list_add_tail(&rq->queuelist, &q->flush_list); + list_move_tail(&rq->queuelist, &q->flush_list); spin_unlock(&q->requeue_lock); blk_mq_kick_requeue_list(q); break; @@ -202,7 +201,7 @@ static void blk_flush_complete_seq(struct request *rq, * flush data request completion path. Restore @rq for * normal completion and end it. */ - list_del_init(&rq->flush.list); + list_del_init(&rq->queuelist); blk_flush_restore_request(rq); blk_mq_end_request(rq, error); break; @@ -258,7 +257,7 @@ static enum rq_end_io_ret flush_end_io(struct request *flush_rq, fq->flush_running_idx ^= 1; /* and push the waiting requests to the next stage */ - list_for_each_entry_safe(rq, n, running, flush.list) { + list_for_each_entry_safe(rq, n, running, queuelist) { unsigned int seq = blk_flush_cur_seq(rq); BUG_ON(seq != REQ_FSEQ_PREFLUSH && seq != REQ_FSEQ_POSTFLUSH); @@ -292,7 +291,7 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq, { struct list_head *pending = &fq->flush_queue[fq->flush_pending_idx]; struct request *first_rq = - list_first_entry(pending, struct request, flush.list); + list_first_entry(pending, struct request, queuelist); struct request *flush_rq = fq->flush_rq; /* C1 described at the top of this file */ @@ -376,6 +375,11 @@ static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq, */ spin_lock_irqsave(&fq->mq_flush_lock, flags); fq->flush_data_in_flight--; + /* + * May have been corrupted by rq->rq_next reuse, we need to + * re-initialize rq->queuelist before reusing it here. + */ + INIT_LIST_HEAD(&rq->queuelist); blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error); spin_unlock_irqrestore(&fq->mq_flush_lock, flags); @@ -386,7 +390,6 @@ static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq, static void blk_rq_init_flush(struct request *rq) { rq->flush.seq = 0; - INIT_LIST_HEAD(&rq->flush.list); rq->rq_flags |= RQF_FLUSH_SEQ; rq->flush.saved_end_io = rq->end_io; /* Usually NULL */ rq->end_io = mq_flush_data_end_io; diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 34d400171b3e..ab790eba5fcf 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -176,7 +176,6 @@ struct request { struct { unsigned int seq; - struct list_head list; rq_end_io_fn *saved_end_io; } flush;