From patchwork Mon Jun 17 06:04:48 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 805665 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 34785187359; Mon, 17 Jun 2024 06:06:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718604420; cv=none; b=aqGmVyLVmpl65ZtfZb14QImmlpO+PbcxCpI5M5EFBVwT9E0REGCwRO4F9dhAzgdELYQbbHxwjg8KzsaLoTJ8PZ/C3e67UPRtW/vq4wb3jB7CCDWgLzsFFascfkIRN28LWmlyQ2UyvPlpMBpmOqANgwk+hnoCz7MUGeaGj5uenpA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718604420; c=relaxed/simple; bh=fJAgLeWve0LqoHqIJiAzXZwwRmY0p/qTRnXlVhA2vkc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GX3+aGYW39eEhmGJNe3hpc1ND75c2k/NCFGxZvNoZJr1aslhSf3fbyyqtNYfkqOTtJk32mOD3MIsaV4w75xMUun2It+BLmd/XQkjzJasO/p+rkLsIbwvY2DsYoa0AZB3D8aH5Je8SOAkTTu+aRvxuqn72PAOiYvvmm7r/t0nzx4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=Mw/amKwi; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Mw/amKwi" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=XDMmYQEhqfxG2aJiRL/4ZYDAujH/dkiKXCLXQktKzVU=; b=Mw/amKwikts8mPqEzitq6S7gSt SqUiszPIuksF9x0en8yoe/G92F4AAVDiQml0cDIv/Bs4SWaYMa4ZjPmLHxhxZmae04xvteiFICg4q uFeMrOx1jCTsbVi93WFy17asl+ugvr0swUM7/onpistyMzuFHwhr67Tb4gAPx3xZEJxWeOFbhkyy0 eDdqkSIQYDTyAvjjOdDfDOhG8hJrCetKbzdTk8hn5jTMBtvclvfbmsu6urUsWKk5lUJVNpJTt4bTA 4t55FwPr4cOtwfysvFUJ3BFhJ4GHXOkytdQUNpzS2Mlt39fBxfePUyoTnd9rZjlIih0sPH3kMopQ8 Hp4NGWUw==; Received: from [91.187.204.140] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1sJ5Vp-00000009J4S-1rbZ; Mon, 17 Jun 2024 06:06:42 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Geert Uytterhoeven , Richard Weinberger , Philipp Reisner , Lars Ellenberg , =?utf-8?q?Christoph_B=C3=B6hmwa?= =?utf-8?q?lder?= , Josef Bacik , Ming Lei , "Michael S. Tsirkin" , Jason Wang , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Song Liu , Yu Kuai , Vineeth Vijayan , "Martin K. Petersen" , linux-m68k@lists.linux-m68k.org, linux-um@lists.infradead.org, drbd-dev@lists.linbit.com, nbd@other.debian.org, linuxppc-dev@lists.ozlabs.org, ceph-devel@vger.kernel.org, virtualization@lists.linux.dev, xen-devel@lists.xenproject.org, linux-bcache@vger.kernel.org, dm-devel@lists.linux.dev, linux-raid@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mtd@lists.infradead.org, nvdimm@lists.linux.dev, linux-nvme@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, Damien Le Moal Subject: [PATCH 21/26] block: move the poll flag to queue_limits Date: Mon, 17 Jun 2024 08:04:48 +0200 Message-ID: <20240617060532.127975-22-hch@lst.de> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240617060532.127975-1-hch@lst.de> References: <20240617060532.127975-1-hch@lst.de> Precedence: bulk X-Mailing-List: ceph-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Move the poll flag into the queue_limits feature field so that it can be set atomically with the queue frozen. Stacking drivers are simplified in that they now can simply set the flag, and blk_stack_limits will clear it when the features is not supported by any of the underlying devices. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal --- block/blk-core.c | 5 ++-- block/blk-mq-debugfs.c | 1 - block/blk-mq.c | 31 +++++++++++--------- block/blk-settings.c | 10 ++++--- block/blk-sysfs.c | 4 +-- drivers/md/dm-table.c | 54 +++++++++-------------------------- drivers/nvme/host/multipath.c | 12 +------- include/linux/blkdev.h | 4 ++- 8 files changed, 45 insertions(+), 76 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 2b45a4df9a1aa1..8d9fbd353fc7fc 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -791,7 +791,7 @@ void submit_bio_noacct(struct bio *bio) } } - if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) + if (!(q->limits.features & BLK_FEAT_POLL)) bio_clear_polled(bio); switch (bio_op(bio)) { @@ -915,8 +915,7 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags) return 0; q = bdev_get_queue(bdev); - if (cookie == BLK_QC_T_NONE || - !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) + if (cookie == BLK_QC_T_NONE || !(q->limits.features & BLK_FEAT_POLL)) return 0; blk_flush_plug(current->plug, false); diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index f4fa820251ce83..3a21527913840d 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -87,7 +87,6 @@ static const char *const blk_queue_flag_name[] = { QUEUE_FLAG_NAME(NOXMERGES), QUEUE_FLAG_NAME(SAME_FORCE), QUEUE_FLAG_NAME(INIT_DONE), - QUEUE_FLAG_NAME(POLL), QUEUE_FLAG_NAME(STATS), QUEUE_FLAG_NAME(REGISTERED), QUEUE_FLAG_NAME(QUIESCED), diff --git a/block/blk-mq.c b/block/blk-mq.c index 43235acc87505f..e2b9710ddc5ad1 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4109,6 +4109,12 @@ void blk_mq_release(struct request_queue *q) blk_mq_sysfs_deinit(q); } +static bool blk_mq_can_poll(struct blk_mq_tag_set *set) +{ + return set->nr_maps > HCTX_TYPE_POLL && + set->map[HCTX_TYPE_POLL].nr_queues; +} + struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set, struct queue_limits *lim, void *queuedata) { @@ -4119,6 +4125,8 @@ struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set, if (!lim) lim = &default_lim; lim->features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT; + if (blk_mq_can_poll(set)) + lim->features |= BLK_FEAT_POLL; q = blk_alloc_queue(lim, set->numa_node); if (IS_ERR(q)) @@ -4273,17 +4281,6 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, mutex_unlock(&q->sysfs_lock); } -static void blk_mq_update_poll_flag(struct request_queue *q) -{ - struct blk_mq_tag_set *set = q->tag_set; - - if (set->nr_maps > HCTX_TYPE_POLL && - set->map[HCTX_TYPE_POLL].nr_queues) - blk_queue_flag_set(QUEUE_FLAG_POLL, q); - else - blk_queue_flag_clear(QUEUE_FLAG_POLL, q); -} - int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, struct request_queue *q) { @@ -4311,7 +4308,6 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, q->tag_set = set; q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; - blk_mq_update_poll_flag(q); INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); INIT_LIST_HEAD(&q->flush_list); @@ -4798,8 +4794,10 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, fallback: blk_mq_update_queue_map(set); list_for_each_entry(q, &set->tag_list, tag_set_list) { + struct queue_limits lim; + blk_mq_realloc_hw_ctxs(set, q); - blk_mq_update_poll_flag(q); + if (q->nr_hw_queues != set->nr_hw_queues) { int i = prev_nr_hw_queues; @@ -4811,6 +4809,13 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, set->nr_hw_queues = prev_nr_hw_queues; goto fallback; } + lim = queue_limits_start_update(q); + if (blk_mq_can_poll(set)) + lim.features |= BLK_FEAT_POLL; + else + lim.features &= ~BLK_FEAT_POLL; + if (queue_limits_commit_update(q, &lim) < 0) + pr_warn("updating the poll flag failed\n"); blk_mq_map_swqueue(q); } diff --git a/block/blk-settings.c b/block/blk-settings.c index bf4622c19b5c09..026ba68d829856 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -460,13 +460,15 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, t->features |= (b->features & BLK_FEAT_INHERIT_MASK); /* - * BLK_FEAT_NOWAIT needs to be supported both by the stacking driver - * and all underlying devices. The stacking driver sets the flag - * before stacking the limits, and this will clear the flag if any - * of the underlying devices does not support it. + * BLK_FEAT_NOWAIT and BLK_FEAT_POLL need to be supported both by the + * stacking driver and all underlying devices. The stacking driver sets + * the flags before stacking the limits, and this will clear the flags + * if any of the underlying devices does not support it. */ if (!(b->features & BLK_FEAT_NOWAIT)) t->features &= ~BLK_FEAT_NOWAIT; + if (!(b->features & BLK_FEAT_POLL)) + t->features &= ~BLK_FEAT_POLL; t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors); t->max_user_sectors = min_not_zero(t->max_user_sectors, diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index cde525724831ef..da4e96d686f91e 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -394,13 +394,13 @@ static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page, static ssize_t queue_poll_show(struct request_queue *q, char *page) { - return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page); + return queue_var_show(q->limits.features & BLK_FEAT_POLL, page); } static ssize_t queue_poll_store(struct request_queue *q, const char *page, size_t count) { - if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) + if (!(q->limits.features & BLK_FEAT_POLL)) return -EINVAL; pr_info_ratelimited("writes to the poll attribute are ignored.\n"); pr_info_ratelimited("please use driver specific parameters instead.\n"); diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index e44697037e86f4..ca1f136575cff4 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -582,7 +582,7 @@ int dm_split_args(int *argc, char ***argvp, char *input) static void dm_set_stacking_limits(struct queue_limits *limits) { blk_set_stacking_limits(limits); - limits->features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT; + limits->features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT | BLK_FEAT_POLL; } /* @@ -1024,14 +1024,13 @@ bool dm_table_request_based(struct dm_table *t) return __table_type_request_based(dm_table_get_type(t)); } -static bool dm_table_supports_poll(struct dm_table *t); - static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md) { enum dm_queue_mode type = dm_table_get_type(t); unsigned int per_io_data_size = 0, front_pad, io_front_pad; unsigned int min_pool_size = 0, pool_size; struct dm_md_mempools *pools; + unsigned int bioset_flags = 0; if (unlikely(type == DM_TYPE_NONE)) { DMERR("no table type is set, can't allocate mempools"); @@ -1048,6 +1047,9 @@ static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device * goto init_bs; } + if (md->queue->limits.features & BLK_FEAT_POLL) + bioset_flags |= BIOSET_PERCPU_CACHE; + for (unsigned int i = 0; i < t->num_targets; i++) { struct dm_target *ti = dm_table_get_target(t, i); @@ -1060,8 +1062,7 @@ static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device * io_front_pad = roundup(per_io_data_size, __alignof__(struct dm_io)) + DM_IO_BIO_OFFSET; - if (bioset_init(&pools->io_bs, pool_size, io_front_pad, - dm_table_supports_poll(t) ? BIOSET_PERCPU_CACHE : 0)) + if (bioset_init(&pools->io_bs, pool_size, io_front_pad, bioset_flags)) goto out_free_pools; if (t->integrity_supported && bioset_integrity_create(&pools->io_bs, pool_size)) @@ -1404,14 +1405,6 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) return &t->targets[(KEYS_PER_NODE * n) + k]; } -static int device_not_poll_capable(struct dm_target *ti, struct dm_dev *dev, - sector_t start, sector_t len, void *data) -{ - struct request_queue *q = bdev_get_queue(dev->bdev); - - return !test_bit(QUEUE_FLAG_POLL, &q->queue_flags); -} - /* * type->iterate_devices() should be called when the sanity check needs to * iterate and check all underlying data devices. iterate_devices() will @@ -1459,19 +1452,6 @@ static int count_device(struct dm_target *ti, struct dm_dev *dev, return 0; } -static bool dm_table_supports_poll(struct dm_table *t) -{ - for (unsigned int i = 0; i < t->num_targets; i++) { - struct dm_target *ti = dm_table_get_target(t, i); - - if (!ti->type->iterate_devices || - ti->type->iterate_devices(ti, device_not_poll_capable, NULL)) - return false; - } - - return true; -} - /* * Check whether a table has no data devices attached using each * target's iterate_devices method. @@ -1817,6 +1797,13 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, if (!dm_table_supports_nowait(t)) limits->features &= ~BLK_FEAT_NOWAIT; + /* + * The current polling impementation does not support request based + * stacking. + */ + if (!__table_type_bio_based(t->type)) + limits->features &= ~BLK_FEAT_POLL; + if (!dm_table_supports_discards(t)) { limits->max_hw_discard_sectors = 0; limits->discard_granularity = 0; @@ -1858,21 +1845,6 @@ int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, return r; dm_update_crypto_profile(q, t); - - /* - * Check for request-based device is left to - * dm_mq_init_request_queue()->blk_mq_init_allocated_queue(). - * - * For bio-based device, only set QUEUE_FLAG_POLL when all - * underlying devices supporting polling. - */ - if (__table_type_bio_based(t->type)) { - if (dm_table_supports_poll(t)) - blk_queue_flag_set(QUEUE_FLAG_POLL, q); - else - blk_queue_flag_clear(QUEUE_FLAG_POLL, q); - } - return 0; } diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 61a162c9cf4e6c..4933194d00e592 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -538,7 +538,7 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) blk_set_stacking_limits(&lim); lim.dma_alignment = 3; - lim.features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT; + lim.features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT | BLK_FEAT_POLL; if (head->ids.csi != NVME_CSI_ZNS) lim.max_zone_append_sectors = 0; @@ -549,16 +549,6 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head) head->disk->private_data = head; sprintf(head->disk->disk_name, "nvme%dn%d", ctrl->subsys->instance, head->instance); - - /* - * This assumes all controllers that refer to a namespace either - * support poll queues or not. That is not a strict guarantee, - * but if the assumption is wrong the effect is only suboptimal - * performance but not correctness problem. - */ - if (ctrl->tagset->nr_maps > HCTX_TYPE_POLL && - ctrl->tagset->map[HCTX_TYPE_POLL].nr_queues) - blk_queue_flag_set(QUEUE_FLAG_POLL, head->disk->queue); return 0; } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 7022e06a3dd9a3..cd27b66cbacc00 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -310,6 +310,9 @@ enum { /* supports DAX */ BLK_FEAT_DAX = (1u << 8), + + /* supports I/O polling */ + BLK_FEAT_POLL = (1u << 9), }; /* @@ -577,7 +580,6 @@ struct request_queue { #define QUEUE_FLAG_NOXMERGES 9 /* No extended merges */ #define QUEUE_FLAG_SAME_FORCE 12 /* force complete on same CPU */ #define QUEUE_FLAG_INIT_DONE 14 /* queue is initialized */ -#define QUEUE_FLAG_POLL 16 /* IO polling enabled if set */ #define QUEUE_FLAG_STATS 20 /* track IO start and completion times */ #define QUEUE_FLAG_REGISTERED 22 /* queue has been registered to a disk */ #define QUEUE_FLAG_QUIESCED 24 /* queue has been quiesced */