From: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
In the event that the IRQ thread is extremely busy, the
processing of an rcd wait list can be delayed by quite
a bit until the IRQ thread completes its work.
The QP reset reference count wait can then appear to be stuck, thus
causing up a QP destroy to emit the hung task diagnostic.
Fix by processing the qp wait list periodically from the thread. The
interval is a multiple (currently 4) of the MAX_PKT_RECV.
Also, reduce some of the excessive inlining. The guidelines
are per packet is ok inline, otherwise the choice is based on
likelyhood of execution.
Reviewed-by: Sebastian Sanchez <sebastian.sanchez@xxxxxxxxx>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
---
drivers/infiniband/hw/hfi1/driver.c | 121 +++++++++++++++++++----------------
1 files changed, 67 insertions(+), 54 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/driver.c b/drivers/infiniband/hw/hfi1/driver.c
index 4fbaee6..29db673 100644
--- a/drivers/infiniband/hw/hfi1/driver.c
+++ b/drivers/infiniband/hw/hfi1/driver.c
@@ -100,6 +100,11 @@
* MAX_PKT_RCV is the max # if packets processed per receive interrupt.
*/
#define MAX_PKT_RECV 64
+/*
+ * MAX_PKT_THREAD_RCV is the max # of packets processed before
+ * the qp_wait_list queue is flushed.
+ */
+#define MAX_PKT_RECV_THREAD (MAX_PKT_RECV * 4)
#define EGR_HEAD_UPDATE_THRESHOLD 16
struct hfi1_ib_stats hfi1_stats;
@@ -259,7 +264,7 @@ int hfi1_count_units(int *npresentp, int *nupp)
* allowed size ranges for the respective type and, optionally,
* return the proper encoding.
*/
-inline int hfi1_rcvbuf_validate(u32 size, u8 type, u16 *encoded)
+int hfi1_rcvbuf_validate(u32 size, u8 type, u16 *encoded)
{
if (unlikely(!PAGE_ALIGNED(size)))
return 0;
@@ -654,24 +659,68 @@ static void __prescan_rxq(struct hfi1_packet *packet)
}
}
-static inline int skip_rcv_packet(struct hfi1_packet *packet, int thread)
+static void process_rcv_qp_work(struct hfi1_ctxtdata *rcd)
+{
+ struct rvt_qp *qp, *nqp;
+
+ /*
+ * Iterate over all QPs waiting to respond.
+ * The list won't change since the IRQ is only run on one CPU.
+ */
+ list_for_each_entry_safe(qp, nqp, &rcd->qp_wait_list, rspwait) {
+ list_del_init(&qp->rspwait);
+ if (qp->r_flags & RVT_R_RSP_NAK) {
+ qp->r_flags &= ~RVT_R_RSP_NAK;
+ hfi1_send_rc_ack(rcd, qp, 0);
+ }
+ if (qp->r_flags & RVT_R_RSP_SEND) {
+ unsigned long flags;
+
+ qp->r_flags &= ~RVT_R_RSP_SEND;
+ spin_lock_irqsave(&qp->s_lock, flags);
+ if (ib_rvt_state_ops[qp->state] &
+ RVT_PROCESS_OR_FLUSH_SEND)
+ hfi1_schedule_send(qp);
+ spin_unlock_irqrestore(&qp->s_lock, flags);
+ }
+ rvt_put_qp(qp);
+ }
+}
+
+static noinline int max_packet_exceeded(struct hfi1_packet *packet, int thread)
+{
+ if (thread) {
+ if ((packet->numpkt & (MAX_PKT_RECV_THREAD - 1)) == 0)
+ /* allow defered processing */
+ process_rcv_qp_work(packet->rcd);
+ cond_resched();
+ return RCV_PKT_OK;
+ } else {
+ this_cpu_inc(*packet->rcd->dd->rcv_limit);
+ return RCV_PKT_LIMIT;
+ }
+}
+
+static inline int check_max_packet(struct hfi1_packet *packet, int thread)
{
int ret = RCV_PKT_OK;
+ if (unlikely((packet->numpkt & (MAX_PKT_RECV - 1)) == 0))
+ ret = max_packet_exceeded(packet, thread);
+ return ret;
+}
+
+static noinline int skip_rcv_packet(struct hfi1_packet *packet, int thread)
+{
+ int ret;
+
/* Set up for the next packet */
packet->rhqoff += packet->rsize;
if (packet->rhqoff >= packet->maxcnt)
packet->rhqoff = 0;
packet->numpkt++;
- if (unlikely((packet->numpkt & (MAX_PKT_RECV - 1)) == 0)) {
- if (thread) {
- cond_resched();
- } else {
- ret = RCV_PKT_LIMIT;
- this_cpu_inc(*packet->rcd->dd->rcv_limit);
- }
- }
+ ret = check_max_packet(packet, thread);
packet->rhf_addr = (__le32 *)packet->rcd->rcvhdrq + packet->rhqoff +
packet->rcd->dd->rhf_offset;
@@ -682,7 +731,7 @@ static inline int skip_rcv_packet(struct hfi1_packet *packet, int thread)
static inline int process_rcv_packet(struct hfi1_packet *packet, int thread)
{
- int ret = RCV_PKT_OK;
+ int ret;
packet->hdr = hfi1_get_msgheader(packet->rcd->dd,
packet->rhf_addr);
@@ -723,14 +772,7 @@ static inline int process_rcv_packet(struct hfi1_packet *packet, int thread)
if (packet->rhqoff >= packet->maxcnt)
packet->rhqoff = 0;
- if (unlikely((packet->numpkt & (MAX_PKT_RECV - 1)) == 0)) {
- if (thread) {
- cond_resched();
- } else {
- ret = RCV_PKT_LIMIT;
- this_cpu_inc(*packet->rcd->dd->rcv_limit);
- }
- }
+ ret = check_max_packet(packet, thread);
packet->rhf_addr = (__le32 *)packet->rcd->rcvhdrq + packet->rhqoff +
packet->rcd->dd->rhf_offset;
@@ -767,38 +809,6 @@ static inline void finish_packet(struct hfi1_packet *packet)
packet->etail, rcv_intr_dynamic, packet->numpkt);
}
-static inline void process_rcv_qp_work(struct hfi1_packet *packet)
-{
- struct hfi1_ctxtdata *rcd;
- struct rvt_qp *qp, *nqp;
-
- rcd = packet->rcd;
- rcd->head = packet->rhqoff;
-
- /*
- * Iterate over all QPs waiting to respond.
- * The list won't change since the IRQ is only run on one CPU.
- */
- list_for_each_entry_safe(qp, nqp, &rcd->qp_wait_list, rspwait) {
- list_del_init(&qp->rspwait);
- if (qp->r_flags & RVT_R_RSP_NAK) {
- qp->r_flags &= ~RVT_R_RSP_NAK;
- hfi1_send_rc_ack(rcd, qp, 0);
- }
- if (qp->r_flags & RVT_R_RSP_SEND) {
- unsigned long flags;
-
- qp->r_flags &= ~RVT_R_RSP_SEND;
- spin_lock_irqsave(&qp->s_lock, flags);
- if (ib_rvt_state_ops[qp->state] &
- RVT_PROCESS_OR_FLUSH_SEND)
- hfi1_schedule_send(qp);
- spin_unlock_irqrestore(&qp->s_lock, flags);
- }
- rvt_put_qp(qp);
- }
-}
-
/*
* Handle receive interrupts when using the no dma rtail option.
*/
@@ -826,7 +836,8 @@ int handle_receive_interrupt_nodma_rtail(struct hfi1_ctxtdata *rcd, int thread)
last = RCV_PKT_DONE;
process_rcv_update(last, &packet);
}
- process_rcv_qp_work(&packet);
+ process_rcv_qp_work(rcd);
+ rcd->head = packet.rhqoff;
bail:
finish_packet(&packet);
return last;
@@ -854,7 +865,8 @@ int handle_receive_interrupt_dma_rtail(struct hfi1_ctxtdata *rcd, int thread)
last = RCV_PKT_DONE;
process_rcv_update(last, &packet);
}
- process_rcv_qp_work(&packet);
+ process_rcv_qp_work(rcd);
+ rcd->head = packet.rhqoff;
bail:
finish_packet(&packet);
return last;
@@ -1024,7 +1036,8 @@ int handle_receive_interrupt(struct hfi1_ctxtdata *rcd, int thread)
process_rcv_update(last, &packet);
}
- process_rcv_qp_work(&packet);
+ process_rcv_qp_work(rcd);
+ rcd->head = packet.rhqoff;
bail:
/*
--
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