* [PATCH 1/2] staging/rdma/hfi1: add common routine for queuing acks
@ 2015-11-10 14:13 Mike Marciniszyn
2015-11-10 14:14 ` [PATCH 2/2] staging/rdma/hfi1: add ACK coalescing logic Mike Marciniszyn
0 siblings, 1 reply; 2+ messages in thread
From: Mike Marciniszyn @ 2015-11-10 14:13 UTC (permalink / raw)
To: devel-gWbeCf7V1WCQmaza687I9mD2FQJk+8+b
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA,
dledford-H+wXaHxf7aLQT0dZR+AlfA,
linux-next-u79uwXL29TY76Z2rM5mHXA
This patch is a prelimary patch required to
coalesce acks.
The routine to "schedule" a QP for sending a NAK is
now centralized in rc_defer_ack(). The flag is changed
for clarity since the all acks will potentially use
the deferral mechanism.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public•gmane.org>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn-ral2JQCrhuEAvxtiuMwx3w@public•gmane.org>
---
drivers/staging/rdma/hfi1/driver.c | 4 ++-
drivers/staging/rdma/hfi1/rc.c | 42 +++++++++++++-----------------------
drivers/staging/rdma/hfi1/verbs.h | 12 ++++++----
3 files changed, 24 insertions(+), 34 deletions(-)
diff --git a/drivers/staging/rdma/hfi1/driver.c b/drivers/staging/rdma/hfi1/driver.c
index ce69141..e8e0f55 100644
--- a/drivers/staging/rdma/hfi1/driver.c
+++ b/drivers/staging/rdma/hfi1/driver.c
@@ -721,8 +721,8 @@ static inline void process_rcv_qp_work(struct hfi1_packet *packet)
*/
list_for_each_entry_safe(qp, nqp, &rcd->qp_wait_list, rspwait) {
list_del_init(&qp->rspwait);
- if (qp->r_flags & HFI1_R_RSP_NAK) {
- qp->r_flags &= ~HFI1_R_RSP_NAK;
+ if (qp->r_flags & HFI1_R_RSP_DEFERED_ACK) {
+ qp->r_flags &= ~HFI1_R_RSP_DEFERED_ACK;
hfi1_send_rc_ack(rcd, qp, 0);
}
if (qp->r_flags & HFI1_R_RSP_SEND) {
diff --git a/drivers/staging/rdma/hfi1/rc.c b/drivers/staging/rdma/hfi1/rc.c
index 0b19206..6fe0104 100644
--- a/drivers/staging/rdma/hfi1/rc.c
+++ b/drivers/staging/rdma/hfi1/rc.c
@@ -1608,6 +1608,16 @@ bail:
return;
}
+static inline void rc_defered_ack(struct hfi1_ctxtdata *rcd,
+ struct hfi1_qp *qp)
+{
+ if (list_empty(&qp->rspwait)) {
+ qp->r_flags |= HFI1_R_RSP_DEFERED_ACK;
+ atomic_inc(&qp->refcount);
+ list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
+ }
+}
+
/**
* rc_rcv_error - process an incoming duplicate or error RC packet
* @ohdr: the other headers for this packet
@@ -1650,11 +1660,7 @@ static noinline int rc_rcv_error(struct hfi1_other_headers *ohdr, void *data,
* in the receive queue have been processed.
* Otherwise, we end up propagating congestion.
*/
- if (list_empty(&qp->rspwait)) {
- qp->r_flags |= HFI1_R_RSP_NAK;
- atomic_inc(&qp->refcount);
- list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
- }
+ rc_defered_ack(rcd, qp);
}
goto done;
}
@@ -2337,11 +2343,7 @@ rnr_nak:
qp->r_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer;
qp->r_ack_psn = qp->r_psn;
/* Queue RNR NAK for later */
- if (list_empty(&qp->rspwait)) {
- qp->r_flags |= HFI1_R_RSP_NAK;
- atomic_inc(&qp->refcount);
- list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
- }
+ rc_defered_ack(rcd, qp);
return;
nack_op_err:
@@ -2349,11 +2351,7 @@ nack_op_err:
qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR;
qp->r_ack_psn = qp->r_psn;
/* Queue NAK for later */
- if (list_empty(&qp->rspwait)) {
- qp->r_flags |= HFI1_R_RSP_NAK;
- atomic_inc(&qp->refcount);
- list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
- }
+ rc_defered_ack(rcd, qp);
return;
nack_inv_unlck:
@@ -2363,11 +2361,7 @@ nack_inv:
qp->r_nak_state = IB_NAK_INVALID_REQUEST;
qp->r_ack_psn = qp->r_psn;
/* Queue NAK for later */
- if (list_empty(&qp->rspwait)) {
- qp->r_flags |= HFI1_R_RSP_NAK;
- atomic_inc(&qp->refcount);
- list_add_tail(&qp->rspwait, &rcd->qp_wait_list);
- }
+ rc_defered_ack(rcd, qp);
return;
nack_acc_unlck:
@@ -2421,13 +2415,7 @@ void hfi1_rc_hdrerr(
* Otherwise, we end up
* propagating congestion.
*/
- if (list_empty(&qp->rspwait)) {
- qp->r_flags |= HFI1_R_RSP_NAK;
- atomic_inc(&qp->refcount);
- list_add_tail(
- &qp->rspwait,
- &rcd->qp_wait_list);
- }
+ rc_defered_ack(rcd, qp);
} /* Out of sequence NAK */
} /* QP Request NAKs */
}
diff --git a/drivers/staging/rdma/hfi1/verbs.h b/drivers/staging/rdma/hfi1/verbs.h
index e4a8a0d..c5e6f47 100644
--- a/drivers/staging/rdma/hfi1/verbs.h
+++ b/drivers/staging/rdma/hfi1/verbs.h
@@ -547,11 +547,13 @@ struct hfi1_qp {
/*
* Bit definitions for r_flags.
*/
-#define HFI1_R_REUSE_SGE 0x01
-#define HFI1_R_RDMAR_SEQ 0x02
-#define HFI1_R_RSP_NAK 0x04
-#define HFI1_R_RSP_SEND 0x08
-#define HFI1_R_COMM_EST 0x10
+#define HFI1_R_REUSE_SGE 0x01
+#define HFI1_R_RDMAR_SEQ 0x02
+/* defer ack until end of interrupt session */
+#define HFI1_R_RSP_DEFERED_ACK 0x04
+/* relay ack to send engine */
+#define HFI1_R_RSP_SEND 0x08
+#define HFI1_R_COMM_EST 0x10
/*
* Bit definitions for s_flags.
--
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH 2/2] staging/rdma/hfi1: add ACK coalescing logic
2015-11-10 14:13 [PATCH 1/2] staging/rdma/hfi1: add common routine for queuing acks Mike Marciniszyn
@ 2015-11-10 14:14 ` Mike Marciniszyn
0 siblings, 0 replies; 2+ messages in thread
From: Mike Marciniszyn @ 2015-11-10 14:14 UTC (permalink / raw)
To: devel; +Cc: linux-rdma, dledford, linux-next
Implement ACK coalesing logic using a 8 bit counter.
The algorithm is send pio ack when:
- fecn present
- this is the first packet in an interrupt session
- counter is >= HFI1_PSN_CREDIT
Otherwise the ack is defered.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel•com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel•com>
---
drivers/staging/rdma/hfi1/qp.c | 1 +
drivers/staging/rdma/hfi1/rc.c | 29 +++++++++++++++++++++++++++--
drivers/staging/rdma/hfi1/verbs.h | 7 ++++---
3 files changed, 32 insertions(+), 5 deletions(-)
diff --git a/drivers/staging/rdma/hfi1/qp.c b/drivers/staging/rdma/hfi1/qp.c
index df1fa56..8f867ba 100644
--- a/drivers/staging/rdma/hfi1/qp.c
+++ b/drivers/staging/rdma/hfi1/qp.c
@@ -378,6 +378,7 @@ static void reset_qp(struct hfi1_qp *qp, enum ib_qp_type type)
}
qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
qp->r_nak_state = 0;
+ qp->r_adefered = 0;
qp->r_aflags = 0;
qp->r_flags = 0;
qp->s_head = 0;
diff --git a/drivers/staging/rdma/hfi1/rc.c b/drivers/staging/rdma/hfi1/rc.c
index 6fe0104..0193497 100644
--- a/drivers/staging/rdma/hfi1/rc.c
+++ b/drivers/staging/rdma/hfi1/rc.c
@@ -1618,6 +1618,17 @@ static inline void rc_defered_ack(struct hfi1_ctxtdata *rcd,
}
}
+static inline void rc_cancel_ack(struct hfi1_qp *qp)
+{
+ qp->r_adefered = 0;
+ if (list_empty(&qp->rspwait))
+ return;
+ list_del_init(&qp->rspwait);
+ qp->r_flags &= ~HFI1_R_RSP_DEFERED_ACK;
+ if (atomic_dec_and_test(&qp->refcount))
+ wake_up(&qp->wait);
+}
+
/**
* rc_rcv_error - process an incoming duplicate or error RC packet
* @ohdr: the other headers for this packet
@@ -2335,8 +2346,22 @@ send_last:
qp->r_ack_psn = psn;
qp->r_nak_state = 0;
/* Send an ACK if requested or required. */
- if (psn & (1 << 31))
- goto send_ack;
+ if (psn & IB_BTH_REQ_ACK) {
+ if (packet->numpkt == 0) {
+ rc_cancel_ack(qp);
+ goto send_ack;
+ }
+ if (qp->r_adefered >= HFI1_PSN_CREDIT) {
+ rc_cancel_ack(qp);
+ goto send_ack;
+ }
+ if (unlikely(is_fecn)) {
+ rc_cancel_ack(qp);
+ goto send_ack;
+ }
+ qp->r_adefered++;
+ rc_defered_ack(rcd, qp);
+ }
return;
rnr_nak:
diff --git a/drivers/staging/rdma/hfi1/verbs.h b/drivers/staging/rdma/hfi1/verbs.h
index c5e6f47..6d2012b 100644
--- a/drivers/staging/rdma/hfi1/verbs.h
+++ b/drivers/staging/rdma/hfi1/verbs.h
@@ -120,9 +120,9 @@ struct hfi1_packet;
#define HFI1_VENDOR_IPG cpu_to_be16(0xFFA0)
-#define IB_BTH_REQ_ACK (1 << 31)
-#define IB_BTH_SOLICITED (1 << 23)
-#define IB_BTH_MIG_REQ (1 << 22)
+#define IB_BTH_REQ_ACK BIT(31)
+#define IB_BTH_SOLICITED BIT(23)
+#define IB_BTH_MIG_REQ BIT(22)
#define IB_GRH_VERSION 6
#define IB_GRH_VERSION_MASK 0xF
@@ -484,6 +484,7 @@ struct hfi1_qp {
u32 r_psn; /* expected rcv packet sequence number */
u32 r_msn; /* message sequence number */
+ u8 r_adefered; /* number of acks defered */
u8 r_state; /* opcode of last packet received */
u8 r_flags;
u8 r_head_ack_queue; /* index into s_ack_queue[] */
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