UCP/WIREUP: Allow self endpoint to skip a device lane.

[tvegas1]

What?

Fix perftest failure with cuda_ipc but without rc_gda on device tests.

Why?

Workaround: Allow self endpoints to miss a device lane (UCP_FEATURE_DEVICE). This can happen with UCX_TLS=^rc_gda as cuda_ipc does not support same process lane.

How

ucx_perftest uses a self endpoint to copy SN on non-host memory (for instance, ucp_put_lat, to copy the sn). This self endpoint shares the same worker containing the device feature request, hence triggers failure. Using separate context and worker without UCP_FEATURE_DEVICE would mean that we need to register the memory both on context and context_self, which does not seem completely impossible.

Repro:

UCX_NET_DEVICES=ens10f0 UCX_TLS=tcp,cuda ucx_perftest \
  -m cuda -a cuda:0 -t ucp_put_single_bw -w 1000 -n 100000 -s 8 -T 32 localhost

[brminich]

looks like #10933 should fix this problem properly

[tvegas1]

looks like #10933 should fix this problem properly

Seems it currently prevents completely cuda_ipc on same process. Commented on that PR and tested fix below that makes it work:

diff --git a/src/uct/cuda/cuda_ipc/cuda_ipc_iface.c b/src/uct/cuda/cuda_ipc/cuda_ipc_iface.c
index 85228487e..5d6b35b0c 100644
--- a/src/uct/cuda/cuda_ipc/cuda_ipc_iface.c
+++ b/src/uct/cuda/cuda_ipc/cuda_ipc_iface.c
@@ -143,8 +143,7 @@ uct_cuda_ipc_iface_is_reachable_v2(const uct_iface_h tl_iface,
     same_uuid    = (ucs_get_system_id() == dev_addr->system_uuid);

     if ((getpid() == *(pid_t*)params->iface_addr) && same_uuid) {
-        uct_iface_fill_info_str_buf(params, "same process");
-        return 0;
+        return uct_iface_scope_is_reachable(tl_iface, params);
     }

     if (same_uuid ||

[ofirfarjun7]

looks like #10933 should fix this problem properly

It indeed solve the issue for self ep, so I will close this PR.
We still need to make it best effort for the general case.