[V4,12/12] scsi: replace sdev->device_busy with sbitmap

Message ID	20201116090737.50989-13-ming.lei@redhat.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-block-owner@kernel.org> From: Ming Lei <ming.lei@redhat.com> To: Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org, "Martin K . Petersen" <martin.petersen@oracle.com>, linux-scsi@vger.kernel.org Cc: Ming Lei <ming.lei@redhat.com>, Omar Sandoval <osandov@fb.com>, Kashyap Desai <kashyap.desai@broadcom.com>, Sumanesh Samanta <sumanesh.samanta@broadcom.com>, "Ewan D . Milne" <emilne@redhat.com>, Hannes Reinecke <hare@suse.de> Subject: [PATCH V4 12/12] scsi: replace sdev->device_busy with sbitmap Date: Mon, 16 Nov 2020 17:07:37 +0800 Message-Id: <20201116090737.50989-13-ming.lei@redhat.com> In-Reply-To: <20201116090737.50989-1-ming.lei@redhat.com> References: <20201116090737.50989-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	blk-mq/scsi: tracking device queue depth via sbitmap \| expand [V4,00/12] blk-mq/scsi: tracking device queue depth via sbitmap [V4,01/12] sbitmap: remove sbitmap_clear_bit_unlock [V4,02/12] sbitmap: maintain allocation round_robin in sbitmap [V4,03/12] sbitmap: add helpers for updating allocation hint [V4,04/12] sbitmap: move allocation hint into sbitmap [V4,05/12] sbitmap: export sbitmap_weight [V4,06/12] sbitmap: add helper of sbitmap_calculate_shift [V4,07/12] blk-mq: add callbacks for storing & retrieving budget token [V4,08/12] blk-mq: return budget token from .get_budget callback [V4,09/12] scsi: put hot fields of scsi_host_template into one cacheline [V4,10/12] scsi: add scsi_device_busy() to read sdev->device_busy [V4,11/12] scsi: make sure sdev->queue_depth is <= max(shost->can_queue, 1024) [V4,12/12] scsi: replace sdev->device_busy with sbitmap

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index a28d48c850cf..e9e2f0e15ac8 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -218,7 +218,7 @@ void scsi_finish_command(struct scsi_cmnd *cmd) /* * 1024 is big enough for saturating the fast scsi LUN now */ -static int scsi_device_max_queue_depth(struct scsi_device *sdev) +int scsi_device_max_queue_depth(struct scsi_device *sdev) { return max_t(int, sdev->host->can_queue, 1024); } @@ -242,6 +242,8 @@ int scsi_change_queue_depth(struct scsi_device *sdev, int depth) if (sdev->request_queue) blk_set_queue_depth(sdev->request_queue, depth); + sbitmap_resize(&sdev->budget_map, sdev->queue_depth); + return sdev->queue_depth; } EXPORT_SYMBOL(scsi_change_queue_depth); diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 4709418c47e0..f5b675d02929 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -327,7 +327,7 @@ void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd) if (starget->can_queue > 0) atomic_dec(&starget->target_busy); - atomic_dec(&sdev->device_busy); + sbitmap_put(&sdev->budget_map, cmd->budget_token); cmd->budget_token = -1; } @@ -1250,19 +1250,17 @@ scsi_device_state_check(struct scsi_device *sdev, struct request *req) } /* - * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else - * return 0. - * - * Called with the queue_lock held. + * scsi_dev_queue_ready: if we can send requests to sdev, assign one token + * and return the token else return -1. */ static inline int scsi_dev_queue_ready(struct request_queue *q, struct scsi_device *sdev) { - unsigned int busy; + int token; - busy = atomic_inc_return(&sdev->device_busy) - 1; + token = sbitmap_get(&sdev->budget_map); if (atomic_read(&sdev->device_blocked)) { - if (busy) + if (token >= 0) goto out_dec; /* @@ -1274,13 +1272,11 @@ static inline int scsi_dev_queue_ready(struct request_queue *q, "unblocking device at zero depth\n")); } - if (busy >= sdev->queue_depth) - goto out_dec; - - return 1; + return token; out_dec: - atomic_dec(&sdev->device_busy); - return 0; + if (token >= 0) + sbitmap_put(&sdev->budget_map, token); + return -1; } /* @@ -1605,15 +1601,16 @@ static void scsi_mq_put_budget(struct request_queue *q, int budget_token) { struct scsi_device *sdev = q->queuedata; - atomic_dec(&sdev->device_busy); + sbitmap_put(&sdev->budget_map, budget_token); } static int scsi_mq_get_budget(struct request_queue *q) { struct scsi_device *sdev = q->queuedata; + int token = scsi_dev_queue_ready(q, sdev); - if (scsi_dev_queue_ready(q, sdev)) - return 0; + if (token >= 0) + return token; atomic_inc(&sdev->restarts); @@ -1723,7 +1720,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, break; case BLK_STS_RESOURCE: case BLK_STS_ZONE_RESOURCE: - if (atomic_read(&sdev->device_busy) || + if (sbitmap_any_bit_set(&sdev->budget_map) || scsi_device_blocked(sdev)) ret = BLK_STS_DEV_RESOURCE; break; diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 180636d54982..30b35002d2f8 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -5,6 +5,7 @@ #include <linux/device.h> #include <linux/async.h> #include <scsi/scsi_device.h> +#include <linux/sbitmap.h> struct request_queue; struct request; @@ -182,6 +183,8 @@ static inline void scsi_dh_add_device(struct scsi_device *sdev) { } static inline void scsi_dh_release_device(struct scsi_device *sdev) { } #endif +extern int scsi_device_max_queue_depth(struct scsi_device *sdev); + /* * internal scsi timeout functions: for use by mid-layer and transport * classes. diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 9af50e6f94c4..9f1b7f3c650a 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -215,6 +215,7 @@ static void scsi_unlock_floptical(struct scsi_device *sdev, static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, u64 lun, void *hostdata) { + unsigned int depth; struct scsi_device *sdev; int display_failure_msg = 1, ret; struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); @@ -276,8 +277,25 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, WARN_ON_ONCE(!blk_get_queue(sdev->request_queue)); sdev->request_queue->queuedata = sdev; - scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun ? - sdev->host->cmd_per_lun : 1); + depth = sdev->host->cmd_per_lun ?: 1; + + /* + * Use .can_queue as budget map's depth because we have to + * support adjusting queue depth from sysfs. Meantime use + * default device queue depth to figure out sbitmap shift + * since we use this queue depth most of times. + */ + if (sbitmap_init_node(&sdev->budget_map, + scsi_device_max_queue_depth(sdev), + sbitmap_calculate_shift(depth), + GFP_KERNEL, sdev->request_queue->node, + false, true)) { + put_device(&starget->dev); + kfree(sdev); + goto out; + } + + scsi_change_queue_depth(sdev, depth); scsi_sysfs_device_initialize(sdev); @@ -979,6 +997,7 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, scsi_attach_vpd(sdev); sdev->max_queue_depth = sdev->queue_depth; + WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth); sdev->sdev_bflags = *bflags; /* diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index ef5c79037bde..79c36cfdb84b 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -477,6 +477,8 @@ static void scsi_device_dev_release_usercontext(struct work_struct *work) /* NULL queue means the device can't be used */ sdev->request_queue = NULL; + sbitmap_free(&sdev->budget_map); + mutex_lock(&sdev->inquiry_mutex); vpd_pg0 = rcu_replace_pointer(sdev->vpd_pg0, vpd_pg0, lockdep_is_held(&sdev->inquiry_mutex)); diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index dd0b9f690a26..05c7c320ef32 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -8,6 +8,7 @@ #include <linux/blkdev.h> #include <scsi/scsi.h> #include <linux/atomic.h> +#include <linux/sbitmap.h> struct device; struct request_queue; @@ -106,7 +107,7 @@ struct scsi_device { struct list_head siblings; /* list of all devices on this host */ struct list_head same_target_siblings; /* just the devices sharing same target id */ - atomic_t device_busy; /* commands actually active on LLDD */ + struct sbitmap budget_map; atomic_t device_blocked; /* Device returned QUEUE_FULL. */ atomic_t restarts; @@ -592,7 +593,7 @@ static inline int scsi_device_supports_vpd(struct scsi_device *sdev) static inline int scsi_device_busy(struct scsi_device *sdev) { - return atomic_read(&sdev->device_busy); + return sbitmap_weight(&sdev->budget_map); } #define MODULE_ALIAS_SCSI_DEVICE(type) \

[V4,12/12] scsi: replace sdev->device_busy with sbitmap

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