Support a PAPI_DISABLE_COMPONENTS environment variable

[sbkathpe]

Description of Feature Request

Sometimes a PAPI component configured for the PAPI library can exhibit unexpected behavior or else otherwise not execute properly. This usually is during initialization. There is currently no way to disable a configured component outside of using the API. Locally we have enhance PAPI with a PAPI_DISABLE_COMPONENTS environment variable to disable selected components from being activated at runtime. This is particularly helpful for PAPI utilities papi_component_avail, papi_avail, etc.

Below is a GIT diff of how we implemented this environment variable. It has proven useful on a number of occasions where issues in a component prevented the successful execution of a PAPI utility, or even a program using PAPI.

Thanks for the consideration.

@@ -1047,6 +1051,20 @@ PAPI_library_init( int version )
 {
     APIDBG( "Entry: version: %#x\n", version);
 
+#if defined(_CRAY)
+       /* Disable components early */
+
+       char *penv = getenv ("PAPI_DISABLE_COMPONENTS");
+
+       if (penv != NULL) {
+               char *p;
+
+               for (p = strtok (penv, ",:"); p != NULL; p = strtok (NULL, ",:")) {
+                       (void) PAPI_disable_component_by_name (p);
+               }
+       }
+#endif /* _CRAY */
+
        int tmp = 0;
 
        /* This is a poor attempt at a lock. 

Component

No response

[dbarry9]

For the sake of being comprehensive, I am referencing Issue #416 here so that the PAPI development team can loop back to it.

[dbarry9]

Hi @sbkathpe, could you please checkout PR #548 and verify that it implements this feature?