diff options
| -rw-r--r-- | drivers/scsi/libfc/fc_fcp.c | 78 |
1 files changed, 59 insertions, 19 deletions
diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c index ac5c148d0182..4bfab4f0ccb3 100644 --- a/drivers/scsi/libfc/fc_fcp.c +++ b/drivers/scsi/libfc/fc_fcp.c @@ -52,7 +52,6 @@ struct kmem_cache *scsi_pkt_cachep; #define FC_SRB_DISCONTIG (1 << 4) /* non-sequential data recvd */ #define FC_SRB_COMPL (1 << 5) /* fc_io_compl has been run */ #define FC_SRB_FCP_PROCESSING_TMO (1 << 6) /* timer function processing */ -#define FC_SRB_NOMEM (1 << 7) /* dropped to out of mem */ #define FC_SRB_READ (1 << 1) #define FC_SRB_WRITE (1 << 0) @@ -71,12 +70,16 @@ struct kmem_cache *scsi_pkt_cachep; * struct fc_fcp_internal - FCP layer internal data * @scsi_pkt_pool: Memory pool to draw FCP packets from * @scsi_pkt_queue: Current FCP packets - * @throttled: The FCP packet queue is throttled + * @last_can_queue_ramp_down_time: ramp down time + * @last_can_queue_ramp_up_time: ramp up time + * @max_can_queue: max can_queue size */ struct fc_fcp_internal { mempool_t *scsi_pkt_pool; struct list_head scsi_pkt_queue; - u8 throttled; + unsigned long last_can_queue_ramp_down_time; + unsigned long last_can_queue_ramp_up_time; + int max_can_queue; }; #define fc_get_scsi_internal(x) ((struct fc_fcp_internal *)(x)->scsi_priv) @@ -124,6 +127,7 @@ static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *); #define FC_SCSI_TM_TOV (10 * HZ) #define FC_SCSI_REC_TOV (2 * HZ) #define FC_HOST_RESET_TIMEOUT (30 * HZ) +#define FC_CAN_QUEUE_PERIOD (60 * HZ) #define FC_MAX_ERROR_CNT 5 #define FC_MAX_RECOV_RETRY 3 @@ -327,6 +331,38 @@ static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp) } /** + * fc_fcp_can_queue_ramp_up() - increases can_queue + * @lport: lport to ramp up can_queue + * + * Locking notes: Called with Scsi_Host lock held + */ +static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport) +{ + struct fc_fcp_internal *si = fc_get_scsi_internal(lport); + int can_queue; + + if (si->last_can_queue_ramp_up_time && + (time_before(jiffies, si->last_can_queue_ramp_up_time + + FC_CAN_QUEUE_PERIOD))) + return; + + if (time_before(jiffies, si->last_can_queue_ramp_down_time + + FC_CAN_QUEUE_PERIOD)) + return; + + si->last_can_queue_ramp_up_time = jiffies; + + can_queue = lport->host->can_queue << 1; + if (can_queue >= si->max_can_queue) { + can_queue = si->max_can_queue; + si->last_can_queue_ramp_down_time = 0; + } + lport->host->can_queue = can_queue; + shost_printk(KERN_ERR, lport->host, "libfc: increased " + "can_queue to %d.\n", can_queue); +} + +/** * fc_fcp_can_queue_ramp_down() - reduces can_queue * @lport: lport to reduce can_queue * @@ -335,17 +371,20 @@ static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp) * commands complete or timeout, then try again with a reduced * can_queue. Eventually we will hit the point where we run * on all reserved structs. + * + * Locking notes: Called with Scsi_Host lock held */ static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport) { struct fc_fcp_internal *si = fc_get_scsi_internal(lport); - unsigned long flags; int can_queue; - spin_lock_irqsave(lport->host->host_lock, flags); - if (si->throttled) - goto done; - si->throttled = 1; + if (si->last_can_queue_ramp_down_time && + (time_before(jiffies, si->last_can_queue_ramp_down_time + + FC_CAN_QUEUE_PERIOD))) + return; + + si->last_can_queue_ramp_down_time = jiffies; can_queue = lport->host->can_queue; can_queue >>= 1; @@ -354,8 +393,6 @@ static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport) lport->host->can_queue = can_queue; shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n" "Reducing can_queue to %d.\n", can_queue); -done: - spin_unlock_irqrestore(lport->host->host_lock, flags); } /* @@ -370,10 +407,14 @@ static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport, size_t len) { struct fc_frame *fp; + unsigned long flags; fp = fc_frame_alloc(lport, len); - if (!fp) + if (!fp) { + spin_lock_irqsave(lport->host->host_lock, flags); fc_fcp_can_queue_ramp_down(lport); + spin_unlock_irqrestore(lport->host->host_lock, flags); + } return fp; } @@ -720,8 +761,6 @@ static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg) (size_t) ntohl(dd->ft_burst_len)); if (!rc) seq->rec_data = fsp->xfer_len; - else if (rc == -ENOMEM) - fsp->state |= FC_SRB_NOMEM; } else if (r_ctl == FC_RCTL_DD_SOL_DATA) { /* * received a DATA frame @@ -1734,6 +1773,8 @@ int fc_queuecommand(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *)) rpriv = rport->dd_data; if (!fc_fcp_lport_queue_ready(lport)) { + if (lport->qfull) + fc_fcp_can_queue_ramp_down(lport); rc = SCSI_MLQUEUE_HOST_BUSY; goto out; } @@ -1830,13 +1871,11 @@ static void fc_io_compl(struct fc_fcp_pkt *fsp) } /* - * if a command timed out while we had to try and throttle IO - * and it is now getting cleaned up, then we are about to - * try again so clear the throttled flag incase we get more - * time outs. + * if can_queue ramp down is done then try can_queue ramp up + * since commands are completing now. */ - if (si->throttled && fsp->state & FC_SRB_NOMEM) - si->throttled = 0; + if (si->last_can_queue_ramp_down_time) + fc_fcp_can_queue_ramp_up(lport); sc_cmd = fsp->cmd; fsp->cmd = NULL; @@ -2176,6 +2215,7 @@ int fc_fcp_init(struct fc_lport *lport) if (!si) return -ENOMEM; lport->scsi_priv = si; + si->max_can_queue = lport->host->can_queue; INIT_LIST_HEAD(&si->scsi_pkt_queue); si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep); |
