diff options
| author |   Mike Marciniszyn <mike.marciniszyn@qlogic.com> | 2011-09-23 13:16:49 -0400 |
|---|---|---|
| committer |   Roland Dreier <roland@purestorage.com> | 2011-10-21 09:38:56 -0700 |
| commit | d0f2faf72d51dacf5c5e8dec7dca22d0395896e2 (patch) | |
| tree | 9cdae5f02f9d17dac30c9a140123dc912d897278 /drivers/infiniband/hw/qib | |
| parent | IB/qib: Use RCU for qpn lookup (diff) | |
| download | linux-dev-d0f2faf72d51dacf5c5e8dec7dca22d0395896e2.tar.xz linux-dev-d0f2faf72d51dacf5c5e8dec7dca22d0395896e2.zip | |
IB/qib: Precompute timeout jiffies to optimize latency
A new field is added to qib_qp called timeout_jiffies. It is
initialized upon create and modify.
The field is now used instead of a computation based on qp->timeout.
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to 'drivers/infiniband/hw/qib')
| -rw-r--r-- | drivers/infiniband/hw/qib/qib_qp.c | 9 | ||||
| -rw-r--r-- | drivers/infiniband/hw/qib/qib_rc.c | 7 | ||||
| -rw-r--r-- | drivers/infiniband/hw/qib/qib_verbs.h | 1 |
3 files changed, 11 insertions, 6 deletions
diff --git a/drivers/infiniband/hw/qib/qib_qp.c b/drivers/infiniband/hw/qib/qib_qp.c index 500981bce9c0..7e7e16fbee99 100644 --- a/drivers/infiniband/hw/qib/qib_qp.c +++ b/drivers/infiniband/hw/qib/qib_qp.c @@ -801,8 +801,12 @@ int qib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, if (attr_mask & IB_QP_MIN_RNR_TIMER) qp->r_min_rnr_timer = attr->min_rnr_timer; - if (attr_mask & IB_QP_TIMEOUT) + if (attr_mask & IB_QP_TIMEOUT) { qp->timeout = attr->timeout; + qp->timeout_jiffies = + usecs_to_jiffies((4096UL * (1UL << qp->timeout)) / + 1000UL); + } if (attr_mask & IB_QP_QKEY) qp->qkey = attr->qkey; @@ -1034,6 +1038,9 @@ struct ib_qp *qib_create_qp(struct ib_pd *ibpd, goto bail_swq; } RCU_INIT_POINTER(qp->next, NULL); + qp->timeout_jiffies = + usecs_to_jiffies((4096UL * (1UL << qp->timeout)) / + 1000UL); if (init_attr->srq) sz = 0; else { diff --git a/drivers/infiniband/hw/qib/qib_rc.c b/drivers/infiniband/hw/qib/qib_rc.c index 5d77cb8aa052..ecfa087ad45e 100644 --- a/drivers/infiniband/hw/qib/qib_rc.c +++ b/drivers/infiniband/hw/qib/qib_rc.c @@ -59,8 +59,7 @@ static void start_timer(struct qib_qp *qp) qp->s_flags |= QIB_S_TIMER; qp->s_timer.function = rc_timeout; /* 4.096 usec. * (1 << qp->timeout) */ - qp->s_timer.expires = jiffies + - usecs_to_jiffies((4096UL * (1UL << qp->timeout)) / 1000UL); + qp->s_timer.expires = jiffies + qp->timeout_jiffies; add_timer(&qp->s_timer); } @@ -1519,9 +1518,7 @@ read_middle: * 4.096 usec. * (1 << qp->timeout) */ qp->s_flags |= QIB_S_TIMER; - mod_timer(&qp->s_timer, jiffies + - usecs_to_jiffies((4096UL * (1UL << qp->timeout)) / - 1000UL)); + mod_timer(&qp->s_timer, jiffies + qp->timeout_jiffies); if (qp->s_flags & QIB_S_WAIT_ACK) { qp->s_flags &= ~QIB_S_WAIT_ACK; qib_schedule_send(qp); diff --git a/drivers/infiniband/hw/qib/qib_verbs.h b/drivers/infiniband/hw/qib/qib_verbs.h index d7b6109528a4..0c19ef0c4123 100644 --- a/drivers/infiniband/hw/qib/qib_verbs.h +++ b/drivers/infiniband/hw/qib/qib_verbs.h @@ -496,6 +496,7 @@ struct qib_qp { u32 s_last; /* last completed entry */ u32 s_ssn; /* SSN of tail entry */ u32 s_lsn; /* limit sequence number (credit) */ + unsigned long timeout_jiffies; /* computed from timeout */ struct qib_swqe *s_wq; /* send work queue */ struct qib_swqe *s_wqe; struct qib_rq r_rq; /* receive work queue */ |