From 46a80d62e6e0ccfc9d8a05c5b773405b84a4afd7 Mon Sep 17 00:00:00 2001 From: Mike Marciniszyn Date: Sun, 14 Feb 2016 12:10:04 -0800 Subject: IB/qib, staging/rdma/hfi1: add s_hlock for use in post send This patch adds an additional lock to reduce contention on the s_lock. This lock is used in post_send() so that the post_send is not serialized with the send engine and other send related processing. To do this the s_next_psn is now maintained on post_send() while post_send() related fields are moved to a new cache line. There is an s_avail maintained for the post_send() to mitigate trading cache lines with the send engine. The lock is released/acquired around releasing the just built packet to the egress mechanism. Reviewed-by: Jubin John Reviewed-by: Dennis Dalessandro Signed-off-by: Dean Luick Signed-off-by: Harish Chegondi Signed-off-by: Mike Marciniszyn Signed-off-by: Ira Weiny Signed-off-by: Doug Ledford --- drivers/infiniband/hw/qib/qib_ruc.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'drivers/infiniband/hw/qib/qib_ruc.c') diff --git a/drivers/infiniband/hw/qib/qib_ruc.c b/drivers/infiniband/hw/qib/qib_ruc.c index 2623684745f0..a5f07a64b228 100644 --- a/drivers/infiniband/hw/qib/qib_ruc.c +++ b/drivers/infiniband/hw/qib/qib_ruc.c @@ -391,7 +391,8 @@ static void qib_ruc_loopback(struct rvt_qp *sqp) sqp->s_flags |= RVT_S_BUSY; again: - if (sqp->s_last == sqp->s_head) + smp_read_barrier_depends(); /* see post_one_send() */ + if (sqp->s_last == ACCESS_ONCE(sqp->s_head)) goto clr_busy; wqe = rvt_get_swqe_ptr(sqp, sqp->s_last); @@ -765,22 +766,24 @@ void qib_do_send(struct rvt_qp *qp) qp->s_flags |= RVT_S_BUSY; - spin_unlock_irqrestore(&qp->s_lock, flags); - do { /* Check for a constructed packet to be sent. */ if (qp->s_hdrwords != 0) { + spin_unlock_irqrestore(&qp->s_lock, flags); /* * If the packet cannot be sent now, return and * the send tasklet will be woken up later. */ if (qib_verbs_send(qp, priv->s_hdr, qp->s_hdrwords, qp->s_cur_sge, qp->s_cur_size)) - break; + return; /* Record that s_hdr is empty. */ qp->s_hdrwords = 0; + spin_lock_irqsave(&qp->s_lock, flags); } } while (make_req(qp)); + + spin_unlock_irqrestore(&qp->s_lock, flags); } /* -- cgit v1.2.3