From 6d8d282e1f2f0e9294a6bf28526a6e9cbcb68d5f Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Wed, 11 Oct 2017 10:27:29 -0700 Subject: [PATCH] IB/srp: Make CM timeout dependent on subnet timeout For small networks it is safe to reduce the subnet timeout from its default value (18 for opensm) to 16. Make the SRP CM timeout dependent on the subnet timeout such that decreasing the subnet timeout also causes SRP failover and failback to occur faster. Signed-off-by: Bart Van Assche Reviewed-by: Sagi Grimberg Signed-off-by: Doug Ledford --- drivers/infiniband/ulp/srp/ib_srp.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 463c3ed440eba..972d4b3c5223c 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -711,6 +711,23 @@ out: return ret; } +static u8 srp_get_subnet_timeout(struct srp_host *host) +{ + struct ib_port_attr attr; + int ret; + u8 subnet_timeout = 18; + + ret = ib_query_port(host->srp_dev->dev, host->port, &attr); + if (ret == 0) + subnet_timeout = attr.subnet_timeout; + + if (unlikely(subnet_timeout < 15)) + pr_warn("%s: subnet timeout %d may cause SRP login to fail.\n", + dev_name(&host->srp_dev->dev->dev), subnet_timeout); + + return subnet_timeout; +} + static int srp_send_req(struct srp_rdma_ch *ch, bool multich) { struct srp_target_port *target = ch->target; @@ -719,6 +736,9 @@ static int srp_send_req(struct srp_rdma_ch *ch, bool multich) struct srp_login_req priv; } *req = NULL; int status; + u8 subnet_timeout; + + subnet_timeout = srp_get_subnet_timeout(target->srp_host); req = kzalloc(sizeof *req, GFP_KERNEL); if (!req) @@ -741,8 +761,8 @@ static int srp_send_req(struct srp_rdma_ch *ch, bool multich) * module parameters if anyone cared about setting them. */ req->param.responder_resources = 4; - req->param.remote_cm_response_timeout = 20; - req->param.local_cm_response_timeout = 20; + req->param.remote_cm_response_timeout = subnet_timeout + 2; + req->param.local_cm_response_timeout = subnet_timeout + 2; req->param.retry_count = target->tl_retry_count; req->param.rnr_retry_count = 7; req->param.max_cm_retries = 15; -- 2.39.5