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>
This commit is contained in:
Vu Pham 2013-10-26 14:31:27 +02:00 committed by Roland Dreier
parent 959f58544b
commit 7bb312e4a2
3 changed files with 26 additions and 1 deletions

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@ -61,6 +61,8 @@ Description: Interface for making ib_srp connect to a new target.
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

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@ -390,7 +390,7 @@ static int srp_send_req(struct srp_target_port *target)
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 @@ static ssize_t show_comp_vector(struct device *dev,
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(zero_req_lim, S_IRUGO, show_zero_req_lim, NULL);
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 @@ static struct device_attribute *srp_host_attrs[] = {
&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 @@ enum {
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 @@ static const match_table_t srp_opt_tokens = {
{ 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 @@ static int srp_parse_options(const char *buf, struct srp_target_port *target)
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 @@ static ssize_t srp_create_target(struct device *dev,
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)

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@ -157,6 +157,7 @@ struct srp_target_port {
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];