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authorEddie Wai <eddie.wai@broadcom.com>2011-05-16 11:13:20 -0700
committerJames Bottomley <jbottomley@parallels.com>2011-05-24 12:41:10 -0400
commit9ae58e144df1a4ecc91dcd9eea5a3f4a6d13b5fc (patch)
treecc6ef10a0aa8d4a13aebc7d07bede9eba51069fa /drivers/scsi
parentd5307a078bb0288945c900c6f4a2fd77ba6d0817 (diff)
[SCSI] bnx2i: Optimized the iSCSI offload performance
Modified the event coalescing code for iSCSI offload to combat both corner cases and optimize performance as follows: 1. Added mechanism to loop back a second time to process any leftover CQEs that was generated by the hardware during the time the driver is busy processing previous CQEs in the bh. This not only helps the performance but also fixes the corner case when no more CQEs are being generated in the pipeline; so those leftover CQEs will get a a chance to be processed. 2. Added ARM_CQE_FP to distinguish between fast path arming versus slow path arming. This change will guarantee that the CQEs will always get a chance to be re-armed during fast path completions. 3. Removed the inline event coalescing division for perf optimization. Also fixed a division-by-zero error when the event_coal_div module param was set to 0. 4. Changed the default SQ WQEs size from 256 to 128 to match chip default. 5. Changed the cmd_per_lun from 32 to 24. Signed-off-by: Eddie Wai <eddie.wai@broadcom.com> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <jbottomley@parallels.com>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/bnx2i/bnx2i.h16
-rw-r--r--drivers/scsi/bnx2i/bnx2i_hwi.c26
-rw-r--r--drivers/scsi/bnx2i/bnx2i_iscsi.c8
3 files changed, 31 insertions, 19 deletions
diff --git a/drivers/scsi/bnx2i/bnx2i.h b/drivers/scsi/bnx2i/bnx2i.h
index cfd59023227b..6bdd25a93db9 100644
--- a/drivers/scsi/bnx2i/bnx2i.h
+++ b/drivers/scsi/bnx2i/bnx2i.h
@@ -66,11 +66,11 @@
#define BD_SPLIT_SIZE 32768
/* min, max & default values for SQ/RQ/CQ size, configurable via' modparam */
-#define BNX2I_SQ_WQES_MIN 16
-#define BNX2I_570X_SQ_WQES_MAX 128
-#define BNX2I_5770X_SQ_WQES_MAX 512
-#define BNX2I_570X_SQ_WQES_DEFAULT 128
-#define BNX2I_5770X_SQ_WQES_DEFAULT 256
+#define BNX2I_SQ_WQES_MIN 16
+#define BNX2I_570X_SQ_WQES_MAX 128
+#define BNX2I_5770X_SQ_WQES_MAX 512
+#define BNX2I_570X_SQ_WQES_DEFAULT 128
+#define BNX2I_5770X_SQ_WQES_DEFAULT 128
#define BNX2I_570X_CQ_WQES_MAX 128
#define BNX2I_5770X_CQ_WQES_MAX 512
@@ -115,6 +115,7 @@
#define BNX2X_MAX_CQS 8
#define CNIC_ARM_CQE 1
+#define CNIC_ARM_CQE_FP 2
#define CNIC_DISARM_CQE 0
#define REG_RD(__hba, offset) \
@@ -666,7 +667,9 @@ enum {
* after HBA reset is completed by bnx2i/cnic/bnx2
* modules
* @state: tracks offload connection state machine
- * @teardown_mode: indicates if conn teardown is abortive or orderly
+ * @timestamp: tracks the start time when the ep begins to connect
+ * @num_active_cmds: tracks the number of outstanding commands for this ep
+ * @ec_shift: the amount of shift as part of the event coal calc
* @qp: QP information
* @ids: contains chip allocated *context id* & driver assigned
* *iscsi cid*
@@ -685,6 +688,7 @@ struct bnx2i_endpoint {
u32 state;
unsigned long timestamp;
int num_active_cmds;
+ u32 ec_shift;
struct qp_info qp;
struct ep_handles ids;
diff --git a/drivers/scsi/bnx2i/bnx2i_hwi.c b/drivers/scsi/bnx2i/bnx2i_hwi.c
index a8a2b6b65a3c..5c54a2d9b834 100644
--- a/drivers/scsi/bnx2i/bnx2i_hwi.c
+++ b/drivers/scsi/bnx2i/bnx2i_hwi.c
@@ -138,7 +138,6 @@ void bnx2i_arm_cq_event_coalescing(struct bnx2i_endpoint *ep, u8 action)
u16 next_index;
u32 num_active_cmds;
-
/* Coalesce CQ entries only on 10G devices */
if (!test_bit(BNX2I_NX2_DEV_57710, &ep->hba->cnic_dev_type))
return;
@@ -148,16 +147,19 @@ void bnx2i_arm_cq_event_coalescing(struct bnx2i_endpoint *ep, u8 action)
* interrupts and other unwanted results
*/
cq_db = (struct bnx2i_5771x_cq_db *) ep->qp.cq_pgtbl_virt;
- if (cq_db->sqn[0] && cq_db->sqn[0] != 0xFFFF)
- return;
- if (action == CNIC_ARM_CQE) {
+ if (action != CNIC_ARM_CQE_FP)
+ if (cq_db->sqn[0] && cq_db->sqn[0] != 0xFFFF)
+ return;
+
+ if (action == CNIC_ARM_CQE || action == CNIC_ARM_CQE_FP) {
num_active_cmds = ep->num_active_cmds;
if (num_active_cmds <= event_coal_min)
next_index = 1;
else
next_index = event_coal_min +
- (num_active_cmds - event_coal_min) / event_coal_div;
+ ((num_active_cmds - event_coal_min) >>
+ ep->ec_shift);
if (!next_index)
next_index = 1;
cq_index = ep->qp.cqe_exp_seq_sn + next_index - 1;
@@ -1935,7 +1937,6 @@ cqe_out:
qp->cq_cons_idx++;
}
}
- bnx2i_arm_cq_event_coalescing(bnx2i_conn->ep, CNIC_ARM_CQE);
}
/**
@@ -1949,22 +1950,23 @@ cqe_out:
static void bnx2i_fastpath_notification(struct bnx2i_hba *hba,
struct iscsi_kcqe *new_cqe_kcqe)
{
- struct bnx2i_conn *conn;
+ struct bnx2i_conn *bnx2i_conn;
u32 iscsi_cid;
iscsi_cid = new_cqe_kcqe->iscsi_conn_id;
- conn = bnx2i_get_conn_from_id(hba, iscsi_cid);
+ bnx2i_conn = bnx2i_get_conn_from_id(hba, iscsi_cid);
- if (!conn) {
+ if (!bnx2i_conn) {
printk(KERN_ALERT "cid #%x not valid\n", iscsi_cid);
return;
}
- if (!conn->ep) {
+ if (!bnx2i_conn->ep) {
printk(KERN_ALERT "cid #%x - ep not bound\n", iscsi_cid);
return;
}
-
- bnx2i_process_new_cqes(conn);
+ bnx2i_process_new_cqes(bnx2i_conn);
+ bnx2i_arm_cq_event_coalescing(bnx2i_conn->ep, CNIC_ARM_CQE_FP);
+ bnx2i_process_new_cqes(bnx2i_conn);
}
diff --git a/drivers/scsi/bnx2i/bnx2i_iscsi.c b/drivers/scsi/bnx2i/bnx2i_iscsi.c
index 51a970f3bc70..041928b23cb0 100644
--- a/drivers/scsi/bnx2i/bnx2i_iscsi.c
+++ b/drivers/scsi/bnx2i/bnx2i_iscsi.c
@@ -379,6 +379,7 @@ static struct iscsi_endpoint *bnx2i_alloc_ep(struct bnx2i_hba *hba)
{
struct iscsi_endpoint *ep;
struct bnx2i_endpoint *bnx2i_ep;
+ u32 ec_div;
ep = iscsi_create_endpoint(sizeof(*bnx2i_ep));
if (!ep) {
@@ -393,6 +394,11 @@ static struct iscsi_endpoint *bnx2i_alloc_ep(struct bnx2i_hba *hba)
bnx2i_ep->ep_iscsi_cid = (u16) -1;
bnx2i_ep->hba = hba;
bnx2i_ep->hba_age = hba->age;
+
+ ec_div = event_coal_div;
+ while (ec_div >>= 1)
+ bnx2i_ep->ec_shift += 1;
+
hba->ofld_conns_active++;
init_waitqueue_head(&bnx2i_ep->ofld_wait);
return ep;
@@ -2159,7 +2165,7 @@ static struct scsi_host_template bnx2i_host_template = {
.change_queue_depth = iscsi_change_queue_depth,
.can_queue = 1024,
.max_sectors = 127,
- .cmd_per_lun = 32,
+ .cmd_per_lun = 24,
.this_id = -1,
.use_clustering = ENABLE_CLUSTERING,
.sg_tablesize = ISCSI_MAX_BDS_PER_CMD,