IB/srp: Make transport layer retry count configurable
Allow the InfiniBand RC retry count to be configured by the user as an
option in the target login string. Reducing this retry count allows to
reduce the path failover time.
Signed-off-by: Vu Pham <vu@mellanox.com>
[ bvanassche: Rewrote patch description / changed default retry count ]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/Documentation/ABI/stable/sysfs-driver-ib_srp b/Documentation/ABI/stable/sysfs-driver-ib_srp
index 5c53d28..18e9b27 100644
--- a/Documentation/ABI/stable/sysfs-driver-ib_srp
+++ b/Documentation/ABI/stable/sysfs-driver-ib_srp
@@ -61,6 +61,8 @@
interrupt is handled by a different CPU then the comp_vector
parameter can be used to spread the SRP completion workload
over multiple CPU's.
+ * tl_retry_count, a number in the range 2..7 specifying the
+ IB RC retry count.
What: /sys/class/infiniband_srp/srp-<hca>-<port_number>/ibdev
Date: January 2, 2006
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index f93baf8..11ebf3e 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -390,7 +390,7 @@
req->param.responder_resources = 4;
req->param.remote_cm_response_timeout = 20;
req->param.local_cm_response_timeout = 20;
- req->param.retry_count = 7;
+ req->param.retry_count = target->tl_retry_count;
req->param.rnr_retry_count = 7;
req->param.max_cm_retries = 15;
@@ -1907,6 +1907,14 @@
return sprintf(buf, "%d\n", target->comp_vector);
}
+static ssize_t show_tl_retry_count(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct srp_target_port *target = host_to_target(class_to_shost(dev));
+
+ return sprintf(buf, "%d\n", target->tl_retry_count);
+}
+
static ssize_t show_cmd_sg_entries(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1934,6 +1942,7 @@
static DEVICE_ATTR(local_ib_port, S_IRUGO, show_local_ib_port, NULL);
static DEVICE_ATTR(local_ib_device, S_IRUGO, show_local_ib_device, NULL);
static DEVICE_ATTR(comp_vector, S_IRUGO, show_comp_vector, NULL);
+static DEVICE_ATTR(tl_retry_count, S_IRUGO, show_tl_retry_count, NULL);
static DEVICE_ATTR(cmd_sg_entries, S_IRUGO, show_cmd_sg_entries, NULL);
static DEVICE_ATTR(allow_ext_sg, S_IRUGO, show_allow_ext_sg, NULL);
@@ -1949,6 +1958,7 @@
&dev_attr_local_ib_port,
&dev_attr_local_ib_device,
&dev_attr_comp_vector,
+ &dev_attr_tl_retry_count,
&dev_attr_cmd_sg_entries,
&dev_attr_allow_ext_sg,
NULL
@@ -2073,6 +2083,7 @@
SRP_OPT_ALLOW_EXT_SG = 1 << 10,
SRP_OPT_SG_TABLESIZE = 1 << 11,
SRP_OPT_COMP_VECTOR = 1 << 12,
+ SRP_OPT_TL_RETRY_COUNT = 1 << 13,
SRP_OPT_ALL = (SRP_OPT_ID_EXT |
SRP_OPT_IOC_GUID |
SRP_OPT_DGID |
@@ -2094,6 +2105,7 @@
{ SRP_OPT_ALLOW_EXT_SG, "allow_ext_sg=%u" },
{ SRP_OPT_SG_TABLESIZE, "sg_tablesize=%u" },
{ SRP_OPT_COMP_VECTOR, "comp_vector=%u" },
+ { SRP_OPT_TL_RETRY_COUNT, "tl_retry_count=%u" },
{ SRP_OPT_ERR, NULL }
};
@@ -2257,6 +2269,15 @@
target->comp_vector = token;
break;
+ case SRP_OPT_TL_RETRY_COUNT:
+ if (match_int(args, &token) || token < 2 || token > 7) {
+ pr_warn("bad tl_retry_count parameter '%s' (must be a number between 2 and 7)\n",
+ p);
+ goto out;
+ }
+ target->tl_retry_count = token;
+ break;
+
default:
pr_warn("unknown parameter or missing value '%s' in target creation request\n",
p);
@@ -2311,6 +2332,7 @@
target->cmd_sg_cnt = cmd_sg_entries;
target->sg_tablesize = indirect_sg_entries ? : cmd_sg_entries;
target->allow_ext_sg = allow_ext_sg;
+ target->tl_retry_count = 7;
ret = srp_parse_options(buf, target);
if (ret)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index e641088..84d821b 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -157,6 +157,7 @@
unsigned int scsi_id;
unsigned int sg_tablesize;
int comp_vector;
+ int tl_retry_count;
struct ib_sa_path_rec path;
__be16 orig_dgid[8];