diff options
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r-- | drivers/scsi/scsi_lib.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index a1a0a2903263..600c78065d62 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -345,7 +345,8 @@ static void scsi_dec_host_busy(struct Scsi_Host *shost) unsigned long flags; rcu_read_lock(); - atomic_dec(&shost->host_busy); + if (!shost->use_blk_mq) + atomic_dec(&shost->host_busy); if (unlikely(scsi_host_in_recovery(shost))) { spin_lock_irqsave(shost->host_lock, flags); if (shost->host_failed || shost->host_eh_scheduled) @@ -444,7 +445,12 @@ static inline bool scsi_target_is_busy(struct scsi_target *starget) static inline bool scsi_host_is_busy(struct Scsi_Host *shost) { - if (shost->can_queue > 0 && + /* + * blk-mq can handle host queue busy efficiently via host-wide driver + * tag allocation + */ + + if (!shost->use_blk_mq && shost->can_queue > 0 && atomic_read(&shost->host_busy) >= shost->can_queue) return true; if (atomic_read(&shost->host_blocked) > 0) @@ -1600,9 +1606,12 @@ static inline int scsi_host_queue_ready(struct request_queue *q, if (scsi_host_in_recovery(shost)) return 0; - busy = atomic_inc_return(&shost->host_busy) - 1; + if (!shost->use_blk_mq) + busy = atomic_inc_return(&shost->host_busy) - 1; + else + busy = 0; if (atomic_read(&shost->host_blocked) > 0) { - if (busy) + if (busy || scsi_host_busy(shost)) goto starved; /* @@ -1616,7 +1625,7 @@ static inline int scsi_host_queue_ready(struct request_queue *q, "unblocking host at zero depth\n")); } - if (shost->can_queue > 0 && busy >= shost->can_queue) + if (!shost->use_blk_mq && shost->can_queue > 0 && busy >= shost->can_queue) goto starved; if (shost->host_self_blocked) goto starved; @@ -1702,7 +1711,9 @@ static void scsi_kill_request(struct request *req, struct request_queue *q) * with the locks as normal issue path does. */ atomic_inc(&sdev->device_busy); - atomic_inc(&shost->host_busy); + + if (!shost->use_blk_mq) + atomic_inc(&shost->host_busy); if (starget->can_queue > 0) atomic_inc(&starget->target_busy); |