From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dennis Dalessandro Subject: [PATCH 02/27] IB/hfi1: Process qp wait list in IRQ thread periodically Date: Wed, 08 Feb 2017 05:26:02 -0800 Message-ID: <20170208132601.16442.69915.stgit@scvm10.sc.intel.com> References: <20170208132142.16442.69329.stgit@scvm10.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170208132142.16442.69329.stgit-9QXIwq+3FY+1XWohqUldA0EOCMrvLtNR@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mike Marciniszyn , Sebastian Sanchez List-Id: linux-rdma@vger.kernel.org From: Mike Marciniszyn 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 Reviewed-by: Dennis Dalessandro Signed-off-by: Mike Marciniszyn Signed-off-by: Dennis Dalessandro --- 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: /* -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html