restored missing changes

This commit was SVN r3680.

src/runtime/ompi_progress.c

@@ -17,18 +17,36 @@
 #include "mca/pml/pml.h"
 #include "runtime/ompi_progress.h"
 
-
+                                                                                                                
 static int ompi_progress_event_flag = OMPI_EVLOOP_ONCE;
-
+                                                                                                               
 void ompi_progress_events(int flag)
 {
-    ompi_progress_event_flag = flag;
+    if(flag != 0 || ompi_progress_event_flag == OMPI_EVLOOP_ONCE) {
+        ompi_progress_event_flag = flag;
+    }
 }
-
+                                                                                                               
 void ompi_progress(void)
 {
+    /* progress any outstanding communications */
+    int events = 0;
     if(ompi_progress_event_flag != 0)
-       ompi_event_loop(ompi_progress_event_flag);
-    mca_pml.pml_progress();
+       events += ompi_event_loop(ompi_progress_event_flag);
+    events += mca_pml.pml_progress();
+                                                                                                               
+#if 0
+    /* TSW - disable this until can validate that it doesn't impact SMP
+     * performance
+    */
+    /*
+     * if there is nothing to do - yield the processor - otherwise
+     * we could consume the processor for the entire time slice. If
+     * the processor is oversubscribed - this will result in a best-case
+     * latency equivalent to the time-slice.
+    */
+    if(events == 0)
+        sched_yield();
+#endif
 }