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 <jubin.john@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Mike Marciniszyn
2016-02-14 12:10:04 -08:00
committed by Doug Ledford
parent 20f333b613
commit 46a80d62e6
18 changed files with 320 additions and 222 deletions

View File

@@ -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);
}
/*