PML/SPML/UCX: added evaluation of mmap events

- there was a set of UCX related issues reported which caused
  by mmap API hooks conflicts. We added diagnostic of such
  problems to simplify bug-resolving pipeline

Signed-off-by: Sergey Oblomov <sergeyo@mellanox.com>

Author: Sergey Oblomov

config/ompi_check_ucx.m4

@@ -112,6 +112,9 @@ AC_DEFUN([OMPI_CHECK_UCX],[
                                   ucp_request_check_status, ucp_put_nb, ucp_get_nb],
                                  [], [],
                                  [#include <ucp/api/ucp.h>])
+                  AC_CHECK_DECLS([ucm_test_events],
+                                 [], [],
+                                 [#include <ucm/api/ucm.h>])
                   AC_CHECK_DECLS([UCP_ATOMIC_POST_OP_AND,
                                   UCP_ATOMIC_POST_OP_OR,
                                   UCP_ATOMIC_POST_OP_XOR,

ompi/mca/pml/ucx/pml_ucx.c

@@ -422,6 +422,7 @@ int mca_pml_ucx_add_procs(struct ompi_proc_t **procs, size_t nprocs)
         }
     }
 
+    opal_common_ucx_mca_proc_added();
     return OMPI_SUCCESS;
 }
 

opal/mca/common/ucx/common_ucx.c

@@ -132,6 +132,28 @@ static void opal_common_ucx_mca_fence_complete_cb(int status, void *fenced)
     *(int*)fenced = 1;
 }
 
+void opal_common_ucx_mca_proc_added(void)
+{
+#if HAVE_DECL_UCM_TEST_EVENTS
+    static int warned = 0;
+    static char *mem_hooks_suggestion = "Try to add command line agrument "
+                                        "'--mca opal_common_ucx_opal_mem_hooks 1' to resolve "
+                                        "this issue.";
+    ucs_status_t status;
+
+    if (!warned) {
+        status = ucm_test_events(UCM_EVENT_VM_UNMAPPED);
+        if (status != UCS_OK) {
+            MCA_COMMON_UCX_WARN("UCX is unable to handle VM_UNMAP event. "
+                                "This may cause performance degradation or data "
+                                "corruption. %s",
+                                opal_common_ucx.opal_mem_hooks ? "" : mem_hooks_suggestion);
+            warned = 1;
+        }
+    }
+#endif
+}
+
 OPAL_DECLSPEC int opal_common_ucx_mca_pmix_fence(ucp_worker_h worker)
 {
     volatile int fenced = 0;

opal/mca/common/ucx/common_ucx.h

@@ -49,6 +49,11 @@ BEGIN_C_DECLS
                         __FILE__ ":" MCA_COMMON_UCX_QUOTE(__LINE__) \
                         " Error: " __VA_ARGS__)
 
+#define MCA_COMMON_UCX_WARN(...)                                    \
+    opal_output_verbose(0, opal_common_ucx.output,                  \
+                        __FILE__ ":" MCA_COMMON_UCX_QUOTE(__LINE__) \
+                        " Warning: " __VA_ARGS__)
+
 #define MCA_COMMON_UCX_VERBOSE(_level, ... )                                \
     if (((_level) <= MCA_COMMON_UCX_MAX_VERBOSE) &&                         \
         ((_level) <= opal_common_ucx.verbose)) {                            \
@@ -101,6 +106,7 @@ extern opal_common_ucx_module_t opal_common_ucx;
 
 OPAL_DECLSPEC void opal_common_ucx_mca_register(void);
 OPAL_DECLSPEC void opal_common_ucx_mca_deregister(void);
+OPAL_DECLSPEC void opal_common_ucx_mca_proc_added(void);
 OPAL_DECLSPEC void opal_common_ucx_empty_complete_cb(void *request, ucs_status_t status);
 OPAL_DECLSPEC int opal_common_ucx_mca_pmix_fence(ucp_worker_h worker);
 OPAL_DECLSPEC int opal_common_ucx_del_procs(opal_common_ucx_del_proc_t *procs, size_t count,

oshmem/mca/spml/ucx/spml_ucx.c

@@ -135,6 +135,8 @@ int mca_spml_ucx_del_procs(ompi_proc_t** procs, size_t nprocs)
 
     mca_spml_ucx_ctx_default.ucp_peers = NULL;
 
+    opal_common_ucx_mca_proc_added();
+
     return ret;
 }