Do not preallocate any requests. They are instead automatically

preallocated on the first collective that needs them.
Remove the ompi_coll_tuned_preallocate_memory_comm_size_limit MCA
parameter.

ompi/mca/coll/tuned/coll_tuned.h

@@ -28,7 +28,6 @@ BEGIN_C_DECLS
 /* these are the same across all modules and are loaded at component query time */
 extern int   ompi_coll_tuned_stream;
 extern int   ompi_coll_tuned_priority;
-extern int   ompi_coll_tuned_preallocate_memory_comm_size_limit;
 extern bool  ompi_coll_tuned_use_dynamic_rules;
 extern char* ompi_coll_tuned_dynamic_rules_filename;
 extern int   ompi_coll_tuned_init_tree_fanout;

ompi/mca/coll/tuned/coll_tuned_component.c

@@ -44,7 +44,6 @@ const char *ompi_coll_tuned_component_version_string =
  */
 int   ompi_coll_tuned_stream = -1;
 int   ompi_coll_tuned_priority = 30;
-int   ompi_coll_tuned_preallocate_memory_comm_size_limit = (32 * 1024);
 bool  ompi_coll_tuned_use_dynamic_rules = false;
 char* ompi_coll_tuned_dynamic_rules_filename = (char*) NULL;
 int   ompi_coll_tuned_init_tree_fanout = 4;
@@ -121,16 +120,6 @@ static int tuned_register(void)
                                            MCA_BASE_VAR_SCOPE_READONLY,
                                            &ompi_coll_tuned_priority);
 
-    /* parameter for pre-allocated memory requests etc */
-    ompi_coll_tuned_preallocate_memory_comm_size_limit = (32 * 1024);
-    (void) mca_base_component_var_register(&mca_coll_tuned_component.super.collm_version,
-                                           "pre_allocate_memory_comm_size_limit",
-                                           "Size of communicator were we stop pre-allocating memory for the fixed internal buffer used for message requests etc that is hung off the communicator data segment. I.e. if you have a 100'000 nodes you might not want to pre-allocate 200'000 request handle slots per communicator instance!",
-                                           MCA_BASE_VAR_TYPE_INT, NULL, 0, 0,
-                                           OPAL_INFO_LVL_6,
-                                           MCA_BASE_VAR_SCOPE_READONLY,
-                                           &ompi_coll_tuned_preallocate_memory_comm_size_limit);
-    
     /* some initial guesses at topology parameters */
     ompi_coll_tuned_init_tree_fanout = 4;
     (void) mca_base_component_var_register(&mca_coll_tuned_component.super.collm_version,

ompi/mca/coll/tuned/coll_tuned_module.c

@@ -205,12 +205,6 @@ tuned_module_enable( mca_coll_base_module_t *module,
     if (NULL == data) {
         return OMPI_ERROR;
     }
-    if( size <= ompi_coll_tuned_preallocate_memory_comm_size_limit ) {
-        if (NULL == coll_base_comm_get_reqs(data, size * 2)) {
-            OBJ_RELEASE(data);
-            return OMPI_ERROR;
-        }
-    }
 
     if (ompi_coll_tuned_use_dynamic_rules) {
         OPAL_OUTPUT((ompi_coll_tuned_stream,"coll:tuned:module_init MCW & Dynamic"));