IB/cm: Include HCA ACK delay in local ACK timeout
The IB CM should include the HCA ACK delay when calculating the local
ACK timeout value to use for RC QPs. If the HCA ACK delay is large
enough relative to the packet life time, then if it is not taken into
account, the calculated timeout value ends up being too small, which
can result in "retry exceeded" errors.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 16181d6..c7007c4 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -87,6 +87,7 @@
struct cm_device {
struct list_head list;
struct ib_device *device;
+ u8 ack_delay;
struct cm_port port[0];
};
@@ -95,7 +96,7 @@
union ib_gid dgid;
struct ib_ah_attr ah_attr;
u16 pkey_index;
- u8 packet_life_time;
+ u8 timeout;
};
struct cm_work {
@@ -154,6 +155,7 @@
u8 retry_count;
u8 rnr_retry_count;
u8 service_timeout;
+ u8 target_ack_delay;
struct list_head work_list;
atomic_t work_count;
@@ -293,7 +295,7 @@
av->port = port;
ib_init_ah_from_path(cm_dev->device, port->port_num, path,
&av->ah_attr);
- av->packet_life_time = path->packet_life_time;
+ av->timeout = path->packet_life_time + 1;
return 0;
}
@@ -643,6 +645,25 @@
return 1 << max(iba_time - 8, 0);
}
+/*
+ * calculate: 4.096x2^ack_timeout = 4.096x2^ack_delay + 2x4.096x2^life_time
+ * Because of how ack_timeout is stored, adding one doubles the timeout.
+ * To avoid large timeouts, select the max(ack_delay, life_time + 1), and
+ * increment it (round up) only if the other is within 50%.
+ */
+static u8 cm_ack_timeout(u8 ca_ack_delay, u8 packet_life_time)
+{
+ int ack_timeout = packet_life_time + 1;
+
+ if (ack_timeout >= ca_ack_delay)
+ ack_timeout += (ca_ack_delay >= (ack_timeout - 1));
+ else
+ ack_timeout = ca_ack_delay +
+ (ack_timeout >= (ca_ack_delay - 1));
+
+ return min(31, ack_timeout);
+}
+
static void cm_cleanup_timewait(struct cm_timewait_info *timewait_info)
{
if (timewait_info->inserted_remote_id) {
@@ -686,7 +707,7 @@
* timewait before notifying the user that we've exited timewait.
*/
cm_id_priv->id.state = IB_CM_TIMEWAIT;
- wait_time = cm_convert_to_ms(cm_id_priv->av.packet_life_time + 1);
+ wait_time = cm_convert_to_ms(cm_id_priv->av.timeout);
queue_delayed_work(cm.wq, &cm_id_priv->timewait_info->work.work,
msecs_to_jiffies(wait_time));
cm_id_priv->timewait_info = NULL;
@@ -908,7 +929,8 @@
cm_req_set_primary_sl(req_msg, param->primary_path->sl);
cm_req_set_primary_subnet_local(req_msg, 1); /* local only... */
cm_req_set_primary_local_ack_timeout(req_msg,
- min(31, param->primary_path->packet_life_time + 1));
+ cm_ack_timeout(cm_id_priv->av.port->cm_dev->ack_delay,
+ param->primary_path->packet_life_time));
if (param->alternate_path) {
req_msg->alt_local_lid = param->alternate_path->slid;
@@ -923,7 +945,8 @@
cm_req_set_alt_sl(req_msg, param->alternate_path->sl);
cm_req_set_alt_subnet_local(req_msg, 1); /* local only... */
cm_req_set_alt_local_ack_timeout(req_msg,
- min(31, param->alternate_path->packet_life_time + 1));
+ cm_ack_timeout(cm_id_priv->av.port->cm_dev->ack_delay,
+ param->alternate_path->packet_life_time));
}
if (param->private_data && param->private_data_len)
@@ -1433,7 +1456,8 @@
cm_rep_set_starting_psn(rep_msg, cpu_to_be32(param->starting_psn));
rep_msg->resp_resources = param->responder_resources;
rep_msg->initiator_depth = param->initiator_depth;
- cm_rep_set_target_ack_delay(rep_msg, param->target_ack_delay);
+ cm_rep_set_target_ack_delay(rep_msg,
+ cm_id_priv->av.port->cm_dev->ack_delay);
cm_rep_set_failover(rep_msg, param->failover_accepted);
cm_rep_set_flow_ctrl(rep_msg, param->flow_control);
cm_rep_set_rnr_retry_count(rep_msg, param->rnr_retry_count);
@@ -1680,6 +1704,13 @@
cm_id_priv->responder_resources = rep_msg->initiator_depth;
cm_id_priv->sq_psn = cm_rep_get_starting_psn(rep_msg);
cm_id_priv->rnr_retry_count = cm_rep_get_rnr_retry_count(rep_msg);
+ cm_id_priv->target_ack_delay = cm_rep_get_target_ack_delay(rep_msg);
+ cm_id_priv->av.timeout =
+ cm_ack_timeout(cm_id_priv->target_ack_delay,
+ cm_id_priv->av.timeout - 1);
+ cm_id_priv->alt_av.timeout =
+ cm_ack_timeout(cm_id_priv->target_ack_delay,
+ cm_id_priv->alt_av.timeout - 1);
/* todo: handle peer_to_peer */
@@ -2291,7 +2322,7 @@
work->cm_event.param.mra_rcvd.service_timeout =
cm_mra_get_service_timeout(mra_msg);
timeout = cm_convert_to_ms(cm_mra_get_service_timeout(mra_msg)) +
- cm_convert_to_ms(cm_id_priv->av.packet_life_time);
+ cm_convert_to_ms(cm_id_priv->av.timeout);
spin_lock_irq(&cm_id_priv->lock);
switch (cm_id_priv->id.state) {
@@ -2363,7 +2394,8 @@
cm_lap_set_sl(lap_msg, alternate_path->sl);
cm_lap_set_subnet_local(lap_msg, 1); /* local only... */
cm_lap_set_local_ack_timeout(lap_msg,
- min(31, alternate_path->packet_life_time + 1));
+ cm_ack_timeout(cm_id_priv->av.port->cm_dev->ack_delay,
+ alternate_path->packet_life_time));
if (private_data && private_data_len)
memcpy(lap_msg->private_data, private_data, private_data_len);
@@ -2394,6 +2426,9 @@
ret = cm_init_av_by_path(alternate_path, &cm_id_priv->alt_av);
if (ret)
goto out;
+ cm_id_priv->alt_av.timeout =
+ cm_ack_timeout(cm_id_priv->target_ack_delay,
+ cm_id_priv->alt_av.timeout - 1);
ret = cm_alloc_msg(cm_id_priv, &msg);
if (ret)
@@ -3248,8 +3283,7 @@
*qp_attr_mask |= IB_QP_ALT_PATH;
qp_attr->alt_port_num = cm_id_priv->alt_av.port->port_num;
qp_attr->alt_pkey_index = cm_id_priv->alt_av.pkey_index;
- qp_attr->alt_timeout =
- cm_id_priv->alt_av.packet_life_time + 1;
+ qp_attr->alt_timeout = cm_id_priv->alt_av.timeout;
qp_attr->alt_ah_attr = cm_id_priv->alt_av.ah_attr;
}
ret = 0;
@@ -3287,8 +3321,7 @@
*qp_attr_mask |= IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
IB_QP_RNR_RETRY |
IB_QP_MAX_QP_RD_ATOMIC;
- qp_attr->timeout =
- cm_id_priv->av.packet_life_time + 1;
+ qp_attr->timeout = cm_id_priv->av.timeout;
qp_attr->retry_cnt = cm_id_priv->retry_count;
qp_attr->rnr_retry = cm_id_priv->rnr_retry_count;
qp_attr->max_rd_atomic =
@@ -3302,8 +3335,7 @@
*qp_attr_mask = IB_QP_ALT_PATH | IB_QP_PATH_MIG_STATE;
qp_attr->alt_port_num = cm_id_priv->alt_av.port->port_num;
qp_attr->alt_pkey_index = cm_id_priv->alt_av.pkey_index;
- qp_attr->alt_timeout =
- cm_id_priv->alt_av.packet_life_time + 1;
+ qp_attr->alt_timeout = cm_id_priv->alt_av.timeout;
qp_attr->alt_ah_attr = cm_id_priv->alt_av.ah_attr;
qp_attr->path_mig_state = IB_MIG_REARM;
}
@@ -3343,6 +3375,16 @@
}
EXPORT_SYMBOL(ib_cm_init_qp_attr);
+void cm_get_ack_delay(struct cm_device *cm_dev)
+{
+ struct ib_device_attr attr;
+
+ if (ib_query_device(cm_dev->device, &attr))
+ cm_dev->ack_delay = 0; /* acks will rely on packet life time */
+ else
+ cm_dev->ack_delay = attr.local_ca_ack_delay;
+}
+
static void cm_add_one(struct ib_device *device)
{
struct cm_device *cm_dev;
@@ -3367,6 +3409,7 @@
return;
cm_dev->device = device;
+ cm_get_ack_delay(cm_dev);
set_bit(IB_MGMT_METHOD_SEND, reg_req.method_mask);
for (i = 1; i <= device->phys_port_cnt; i++) {
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 32a0e66..23af7a0 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -2326,7 +2326,6 @@
rep.private_data_len = conn_param->private_data_len;
rep.responder_resources = conn_param->responder_resources;
rep.initiator_depth = conn_param->initiator_depth;
- rep.target_ack_delay = CMA_CM_RESPONSE_TIMEOUT;
rep.failover_accepted = 0;
rep.flow_control = conn_param->flow_control;
rep.rnr_retry_count = conn_param->rnr_retry_count;
diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c
index 2586a3e..424983f 100644
--- a/drivers/infiniband/core/ucm.c
+++ b/drivers/infiniband/core/ucm.c
@@ -823,7 +823,6 @@
param.private_data_len = cmd.len;
param.responder_resources = cmd.responder_resources;
param.initiator_depth = cmd.initiator_depth;
- param.target_ack_delay = cmd.target_ack_delay;
param.failover_accepted = cmd.failover_accepted;
param.flow_control = cmd.flow_control;
param.rnr_retry_count = cmd.rnr_retry_count;
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 6764d21..08b4676 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -281,7 +281,6 @@
rep.private_data_len = sizeof data;
rep.flow_control = 0;
rep.rnr_retry_count = req->rnr_retry_count;
- rep.target_ack_delay = 20; /* FIXME */
rep.srq = 1;
rep.qp_num = qp->qp_num;
rep.starting_psn = psn;
diff --git a/include/rdma/ib_cm.h b/include/rdma/ib_cm.h
index 5c07017..12243e8 100644
--- a/include/rdma/ib_cm.h
+++ b/include/rdma/ib_cm.h
@@ -385,7 +385,6 @@
u8 private_data_len;
u8 responder_resources;
u8 initiator_depth;
- u8 target_ack_delay;
u8 failover_accepted;
u8 flow_control;
u8 rnr_retry_count;