Bogus UCX error message

[rhc54]

Thank you for taking the time to submit an issue!

Background information

What version of Open MPI are you using? (e.g., v4.1.6, v5.0.1, git branch name and hash, etc.)

HEAD of main branch

Describe how Open MPI was installed (e.g., from a source/distribution tarball, from a git clone, from an operating system distribution package, etc.)

From Git repo

If you are building/installing from a git clone, please copy-n-paste the output from git submodule status.

Using external libraries

Please describe the system on which you are running

• Operating system/version: Ubuntu
• Computer hardware: container
• Network type: TCP

---

Details of the problem

UCX libraries are installed, but only TCP is available. No MCA params set. When I run mpi4py tests manually, I get a flood of these:

osc_ucx_component.c:379  Error: OSC UCX component priority set inside component query failed

However, I don't get that message running a simple MPI ring program.

[bosilca]

A quick analysis indicates this is a normal outcome in a setup where:

• ucp_context_init fails because UCX can't be initialized (unlikely because TCP should be enough here)
• opal_common_ucx_support_level() returns OPAL_COMMON_UCX_SUPPORT_NONE — UCX initialized but has no transports supporting the required RMA/AMO features (more likely)

Both are expected "this component is not usable" conditions, and therefore they should not trigger a warning/error but instead be a verbose output. Thus, downgrading from OSC_UCX_ERROR to OSC_UCX_VERBOSE is the right. @janjust

diff --git a/ompi/mca/osc/ucx/osc_ucx_component.c b/ompi/mca/osc/ucx/osc_ucx_component.c
index 635a53a3e0..2f3e19a6f2 100644
--- a/ompi/mca/osc/ucx/osc_ucx_component.c
+++ b/ompi/mca/osc/ucx/osc_ucx_component.c
@@ -376,7 +376,7 @@ static int component_query(struct ompi_win_t *win, void **base, size_t size, ptr
     if (mca_osc_ucx_component.priority_is_set == false) {
         ret = component_set_priority();
         if (OMPI_SUCCESS != ret) {
-            OSC_UCX_ERROR("OSC UCX component priority set inside component query failed \n ");
+            OSC_UCX_VERBOSE(10, "OSC UCX not available (component_set_priority returned %d)", ret);
             return ret;
         }
     }
@@ -580,7 +580,7 @@ static int component_select(struct ompi_win_t *win, void **base, size_t size, pt
         if (mca_osc_ucx_component.priority_is_set == false) {
             ret = component_set_priority();
             if (OMPI_SUCCESS != ret) {
-                OSC_UCX_ERROR("OSC UCX component priority set inside component select failed \n ");
+                OSC_UCX_VERBOSE(10, "OSC UCX not available (component_set_priority returned %d)", ret);
                 return ret;
             }
         }

[rhc54]

Thanks @bosilca ! Appreciate you looking into it!