Fix for MarkerAPI if master process is already pinned, e.g. by a prev…

…ious OpenMP region with LIKWID's pinning. Fixes #602

src/libperfctr.c

@@ -159,6 +159,7 @@ likwid_markerInit(void)
     bstring bEventStr;
     struct bstrList* threadTokens;
     struct bstrList* eventStrings;
+    cpu_set_t cpuset;
     char* modeStr = getenv("LIKWID_MODE");
     char* eventStr = getenv("LIKWID_EVENTS");
     char* cThreadStr = getenv("LIKWID_THREADS");
@@ -193,29 +194,60 @@ likwid_markerInit(void)
 
     if (debugStr != NULL)
     {
-        perfmon_verbosity = atoi(debugStr);
-        verbosity = perfmon_verbosity;
+        verbosity = atoi(debugStr);
+        perfmon_setVerbosity(verbosity);
     }
 
-    topology_init();
-    numa_init();
-    affinity_init();
-    hashTable_init();
-
-#ifndef LIKWID_USE_PERFEVENT
-    HPMmode(atoi(modeStr));
-#endif
-
     bThreadStr = bfromcstr(cThreadStr);
     threadTokens = bsplit(bThreadStr,',');
     num_cpus = threadTokens->qty;
-    for (i=0; i<num_cpus; i++)
+    for (i = 0; i < num_cpus; i++)
     {
         threads2Cpu[i] = ownatoi(bdata(threadTokens->entry[i]));
     }
     bdestroy(bThreadStr);
     bstrListDestroy(threadTokens);
 
+    CPU_ZERO(&cpuset);
+    if (pinStr != NULL)
+    {
+        // If LIKWID should pin the threads, we check whether we are already
+        // in a restricted cpuset with a single hwthread. This happens
+        // when an OpenMP region is executed before LIKWID_MARKER_INIT.
+        // When the first thread starts up, LIKWID pins the master process
+        // and the thread. But we want to get the topology without the restriction
+        // here. We don't need to set it back because the first operation
+        // after getting the topology is the pinning of the master process.
+        int err = sched_getaffinity(0, sizeof(cpu_set_t), &cpuset);
+        if (err == 0)
+        {
+            int count = CPU_COUNT(&cpuset);
+            if (count == 1 && count != num_cpus)
+            {
+                cpu_set_t newcpuset;
+                CPU_ZERO(&newcpuset);
+                for (i = 0; i < num_cpus; i++)
+                {
+                    CPU_SET(threads2Cpu[i], &newcpuset);
+                }
+                err = sched_setaffinity(0, sizeof(cpu_set_t), &newcpuset);
+            }
+        }
+        else
+        {
+            fprintf(stderr,"Failed to get cpuset for master thread.\n");
+        }
+    }
+
+    topology_init();
+    numa_init();
+    affinity_init();
+    hashTable_init();
+
+#ifndef LIKWID_USE_PERFEVENT
+    HPMmode(atoi(modeStr));
+#endif
+
     if (pinStr != NULL)
     {
         likwid_pinThread(threads2Cpu[0]);