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authorJames.Smart@Emulex.Com <James.Smart@Emulex.Com>2005-11-29 16:32:13 -0500
committerJames Bottomley <jejb@mulgrave.(none)>2005-12-13 18:34:14 -0700
commit875fbdfe9b1b4c8f12622a8d8d81428ff0984875 (patch)
tree63c787cb9a7d4a92eaedcc9f8a89a00d5d8f6603 /drivers/scsi/lpfc/lpfc_scsi.c
parent5cc36b3cd0e3610ad7c7e2514160998276798fc0 (diff)
[SCSI] lpfc 8.1.1 : Add polled-mode support
- Add functionality to run in polled mode only. Includes run time attribute to enable mode. - Enable runtime writable hba settings for coallescing and delay parameters Customers have requested a mode in the driver to run strictly polled. This is generally to support an environment where the server is extremely loaded and is looking to reclaim some cpu cycles from adapter interrupt handling. This patch adds a new "poll" attribute, and the following behavior: if value is 0 (default): The driver uses the normal method for i/o completion. It uses the firmware feature of interrupt coalesing. The firmware allows a minimum number of i/o completions before an interrupt, or a maximum time delay between interrupts. By default, the driver sets these to no delay (disabled) or 1 i/o - meaning coalescing is disabled. Attributes were provided to change the coalescing values, but it was a module-load time only and global across all adapters. This patch allows them to be writable on a per-adapter basis. if value is 1 : Interrupts are left enabled, expecting that the user has tuned the interrupt coalescing values. When this setting is enabled, the driver will attempt to service completed i/o whenever new i/o is submitted to the adapter. If the coalescing values are large, and the i/o generation rate steady, an interrupt will be avoided by servicing completed i/o prior to the coalescing thresholds kicking in. However, if the i/o completion load is high enough or i/o generation slow, the coalescion values will ensure that completed i/o is serviced in a timely fashion. if value is 3 : Turns off FCP i/o interrupts altogether. The coalescing values now have no effect. A new attribute "poll_tmo" (default 10ms) exists to set the polling interval for i/o completion. When this setting is enabled, the driver will attempt to service completed i/o and restart the interval timer whenever new i/o is submitted. This behavior allows for servicing of completed i/o sooner than the interval timer, but ensures that if no i/o is being issued, then the interval timer will kick in to service the outstanding i/o. Signed-off-by: James Smart <James.Smart@emulex.com> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/lpfc/lpfc_scsi.c')
-rw-r--r--drivers/scsi/lpfc/lpfc_scsi.c72
1 files changed, 62 insertions, 10 deletions
diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index 7dc7810b748..c422220db0a 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -151,18 +151,22 @@ lpfc_new_scsi_buf(struct lpfc_hba * phba)
}
struct lpfc_scsi_buf*
-lpfc_sli_get_scsi_buf(struct lpfc_hba * phba)
+lpfc_get_scsi_buf(struct lpfc_hba * phba)
{
struct lpfc_scsi_buf * lpfc_cmd = NULL;
struct list_head *scsi_buf_list = &phba->lpfc_scsi_buf_list;
+ unsigned long iflag = 0;
+ spin_lock_irqsave(&phba->scsi_buf_list_lock, iflag);
list_remove_head(scsi_buf_list, lpfc_cmd, struct lpfc_scsi_buf, list);
+ spin_unlock_irqrestore(&phba->scsi_buf_list_lock, iflag);
return lpfc_cmd;
}
static void
lpfc_release_scsi_buf(struct lpfc_hba * phba, struct lpfc_scsi_buf * psb)
{
+ unsigned long iflag = 0;
/*
* There are only two special cases to consider. (1) the scsi command
* requested scatter-gather usage or (2) the scsi command allocated
@@ -180,8 +184,10 @@ lpfc_release_scsi_buf(struct lpfc_hba * phba, struct lpfc_scsi_buf * psb)
}
}
+ spin_lock_irqsave(&phba->scsi_buf_list_lock, iflag);
psb->pCmd = NULL;
list_add_tail(&psb->list, &phba->lpfc_scsi_buf_list);
+ spin_unlock_irqrestore(&phba->scsi_buf_list_lock, iflag);
}
static int
@@ -403,7 +409,6 @@ lpfc_scsi_cmd_iocb_cmpl(struct lpfc_hba *phba, struct lpfc_iocbq *pIocbIn,
struct lpfc_rport_data *rdata = lpfc_cmd->rdata;
struct lpfc_nodelist *pnode = rdata->pnode;
struct scsi_cmnd *cmd = lpfc_cmd->pCmd;
- unsigned long iflag;
lpfc_cmd->result = pIocbOut->iocb.un.ulpWord[4];
lpfc_cmd->status = pIocbOut->iocb.ulpStatus;
@@ -457,9 +462,7 @@ lpfc_scsi_cmd_iocb_cmpl(struct lpfc_hba *phba, struct lpfc_iocbq *pIocbIn,
cmd->scsi_done(cmd);
- spin_lock_irqsave(phba->host->host_lock, iflag);
lpfc_release_scsi_buf(phba, lpfc_cmd);
- spin_unlock_irqrestore(phba->host->host_lock, iflag);
}
static void
@@ -707,6 +710,37 @@ lpfc_info(struct Scsi_Host *host)
return lpfcinfobuf;
}
+static __inline__ void lpfc_poll_rearm_timer(struct lpfc_hba * phba)
+{
+ unsigned long poll_tmo_expires =
+ (jiffies + msecs_to_jiffies(phba->cfg_poll_tmo));
+
+ if (phba->sli.ring[LPFC_FCP_RING].txcmplq_cnt)
+ mod_timer(&phba->fcp_poll_timer,
+ poll_tmo_expires);
+}
+
+void lpfc_poll_start_timer(struct lpfc_hba * phba)
+{
+ lpfc_poll_rearm_timer(phba);
+}
+
+void lpfc_poll_timeout(unsigned long ptr)
+{
+ struct lpfc_hba *phba = (struct lpfc_hba *)ptr;
+ unsigned long iflag;
+
+ spin_lock_irqsave(phba->host->host_lock, iflag);
+
+ if (phba->cfg_poll & ENABLE_FCP_RING_POLLING) {
+ lpfc_sli_poll_fcp_ring (phba);
+ if (phba->cfg_poll & DISABLE_FCP_RING_INT)
+ lpfc_poll_rearm_timer(phba);
+ }
+
+ spin_unlock_irqrestore(phba->host->host_lock, iflag);
+}
+
static int
lpfc_queuecommand(struct scsi_cmnd *cmnd, void (*done) (struct scsi_cmnd *))
{
@@ -733,7 +767,7 @@ lpfc_queuecommand(struct scsi_cmnd *cmnd, void (*done) (struct scsi_cmnd *))
cmnd->result = ScsiResult(DID_BUS_BUSY, 0);
goto out_fail_command;
}
- lpfc_cmd = lpfc_sli_get_scsi_buf (phba);
+ lpfc_cmd = lpfc_get_scsi_buf (phba);
if (lpfc_cmd == NULL) {
lpfc_printf_log(phba, KERN_INFO, LOG_FCP,
"%d:0707 driver's buffer pool is empty, "
@@ -761,11 +795,17 @@ lpfc_queuecommand(struct scsi_cmnd *cmnd, void (*done) (struct scsi_cmnd *))
&lpfc_cmd->cur_iocbq, SLI_IOCB_RET_IOCB);
if (err)
goto out_host_busy_free_buf;
+
+ if (phba->cfg_poll & ENABLE_FCP_RING_POLLING) {
+ lpfc_sli_poll_fcp_ring(phba);
+ if (phba->cfg_poll & DISABLE_FCP_RING_INT)
+ lpfc_poll_rearm_timer(phba);
+ }
+
return 0;
out_host_busy_free_buf:
lpfc_release_scsi_buf(phba, lpfc_cmd);
- cmnd->host_scribble = NULL;
out_host_busy:
return SCSI_MLQUEUE_HOST_BUSY;
@@ -839,9 +879,15 @@ lpfc_abort_handler(struct scsi_cmnd *cmnd)
goto out;
}
+ if (phba->cfg_poll & DISABLE_FCP_RING_INT)
+ lpfc_sli_poll_fcp_ring (phba);
+
/* Wait for abort to complete */
while (lpfc_cmd->pCmd == cmnd)
{
+ if (phba->cfg_poll & DISABLE_FCP_RING_INT)
+ lpfc_sli_poll_fcp_ring (phba);
+
spin_unlock_irq(phba->host->host_lock);
schedule_timeout_uninterruptible(LPFC_ABORT_WAIT*HZ);
spin_lock_irq(phba->host->host_lock);
@@ -905,7 +951,7 @@ lpfc_reset_lun_handler(struct scsi_cmnd *cmnd)
break;
}
- lpfc_cmd = lpfc_sli_get_scsi_buf (phba);
+ lpfc_cmd = lpfc_get_scsi_buf (phba);
if (lpfc_cmd == NULL)
goto out;
@@ -1001,7 +1047,7 @@ lpfc_reset_bus_handler(struct scsi_cmnd *cmnd)
lpfc_block_requests(phba);
spin_lock_irq(shost->host_lock);
- lpfc_cmd = lpfc_sli_get_scsi_buf (phba);
+ lpfc_cmd = lpfc_get_scsi_buf(phba);
if (lpfc_cmd == NULL)
goto out;
@@ -1136,10 +1182,10 @@ lpfc_slave_alloc(struct scsi_device *sdev)
break;
}
- spin_lock_irqsave(phba->host->host_lock, flags);
+ spin_lock_irqsave(&phba->scsi_buf_list_lock, flags);
phba->total_scsi_bufs++;
list_add_tail(&scsi_buf->list, &phba->lpfc_scsi_buf_list);
- spin_unlock_irqrestore(phba->host->host_lock, flags);
+ spin_unlock_irqrestore(&phba->scsi_buf_list_lock, flags);
}
return 0;
}
@@ -1163,6 +1209,12 @@ lpfc_slave_configure(struct scsi_device *sdev)
*/
rport->dev_loss_tmo = phba->cfg_nodev_tmo + 5;
+ if (phba->cfg_poll & ENABLE_FCP_RING_POLLING) {
+ lpfc_sli_poll_fcp_ring(phba);
+ if (phba->cfg_poll & DISABLE_FCP_RING_INT)
+ lpfc_poll_rearm_timer(phba);
+ }
+
return 0;
}