Make I/O to hw queue distribution algorithm a module parameter
Signed-off-by: James Smart <james.smart@xxxxxxxxxx>
---
lpfc.h | 1 +
lpfc_attr.c | 12 ++++++++++++
lpfc_hw4.h | 4 ++++
lpfc_sli.c | 6 +++++-
4 files changed, 22 insertions(+), 1 deletion(-)
diff -upNr a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
--- a/drivers/scsi/lpfc/lpfc_attr.c 2012-07-22 14:26:57.421274202 -0400
+++ b/drivers/scsi/lpfc/lpfc_attr.c 2012-07-22 14:30:08.545267563 -0400
@@ -3778,6 +3778,16 @@ static DEVICE_ATTR(lpfc_max_scsicmpl_tim
LPFC_ATTR_R(ack0, 0, 0, 1, "Enable ACK0 support");
/*
+# lpfc_fcp_io_sched: Determine scheduling algrithmn for issuing FCP cmds
+# range is [0,1]. Default value is 0.
+# For [0], FCP commands are issued to Work Queues ina round robin fashion.
+# For [1], FCP commands are issued to a Work Queue associated with the
+# current CPU.
+*/
+LPFC_ATTR_RW(fcp_io_sched, 0, 0, 1, "Determine scheduling algrithmn for "
+ "issuing commands [0] - Round Robin, [1] - Current CPU");
+
+/*
# lpfc_cr_delay & lpfc_cr_count: Default values for I/O colaesing
# cr_delay (msec) or cr_count outstanding commands. cr_delay can take
# value [0,63]. cr_count can take value [1,255]. Default value of cr_delay
@@ -4001,6 +4011,7 @@ struct device_attribute *lpfc_hba_attrs[
&dev_attr_lpfc_topology,
&dev_attr_lpfc_scan_down,
&dev_attr_lpfc_link_speed,
+ &dev_attr_lpfc_fcp_io_sched,
&dev_attr_lpfc_cr_delay,
&dev_attr_lpfc_cr_count,
&dev_attr_lpfc_multi_ring_support,
@@ -4990,6 +5001,7 @@ struct fc_function_template lpfc_vport_t
void
lpfc_get_cfgparam(struct lpfc_hba *phba)
{
+ lpfc_fcp_io_sched_init(phba, lpfc_fcp_io_sched);
lpfc_cr_delay_init(phba, lpfc_cr_delay);
lpfc_cr_count_init(phba, lpfc_cr_count);
lpfc_multi_ring_support_init(phba, lpfc_multi_ring_support);
diff -upNr a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
--- a/drivers/scsi/lpfc/lpfc.h 2012-07-22 14:26:57.365274203 -0400
+++ b/drivers/scsi/lpfc/lpfc.h 2012-07-22 14:30:08.549267563 -0400
@@ -684,6 +684,7 @@ struct lpfc_hba {
#define LPFC_FCF_FOV 1 /* Fast fcf failover */
#define LPFC_FCF_PRIORITY 2 /* Priority fcf failover */
uint32_t cfg_fcf_failover_policy;
+ uint32_t cfg_fcp_io_sched;
uint32_t cfg_cr_delay;
uint32_t cfg_cr_count;
uint32_t cfg_multi_ring_support;
diff -upNr a/drivers/scsi/lpfc/lpfc_hw4.h b/drivers/scsi/lpfc/lpfc_hw4.h
--- a/drivers/scsi/lpfc/lpfc_hw4.h 2012-07-22 14:26:57.427274202 -0400
+++ b/drivers/scsi/lpfc/lpfc_hw4.h 2012-07-22 14:30:08.557267563 -0400
@@ -187,6 +187,10 @@ struct lpfc_sli_intf {
/* Active interrupt test count */
#define LPFC_ACT_INTR_CNT 4
+/* Algrithmns for scheduling FCP commands to WQs */
+#define LPFC_FCP_SCHED_ROUND_ROBIN 0
+#define LPFC_FCP_SCHED_BY_CPU 1
+
/* Delay Multiplier constant */
#define LPFC_DMULT_CONST 651042
diff -upNr a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
--- a/drivers/scsi/lpfc/lpfc_sli.c 2012-07-22 14:26:57.511274199 -0400
+++ b/drivers/scsi/lpfc/lpfc_sli.c 2012-07-22 14:30:08.566267563 -0400
@@ -7816,7 +7816,11 @@ lpfc_sli4_scmd_to_wqidx_distr(struct lpf
{
int i;
- i = atomic_add_return(1, &phba->fcp_qidx);
+ if (phba->cfg_fcp_io_sched == LPFC_FCP_SCHED_BY_CPU)
+ i = smp_processor_id();
+ else
+ i = atomic_add_return(1, &phba->fcp_qidx);
+
i = (i % phba->cfg_fcp_io_channel);
return i;
}
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