diff --git a/src/libperfctr.c b/src/libperfctr.c
index f26d4d588..09b3fe2f8 100644
--- a/src/libperfctr.c
+++ b/src/libperfctr.c
@@ -69,6 +69,7 @@ static int registered_cpus = 0;
 static pthread_mutex_t globalLock = PTHREAD_MUTEX_INITIALIZER;
 static int use_locks = 0;
 static pthread_mutex_t threadLocks[MAX_NUM_THREADS] = { [ 0 ... (MAX_NUM_THREADS-1)] = PTHREAD_MUTEX_INITIALIZER};
+static int maxRegionNameLength = 100;
 
 
 /* #####   MACROS  -  LOCAL TO THIS SOURCE FILE   ######################### */
@@ -511,13 +512,15 @@ likwid_markerRegisterRegion(const char* regionTag)
     TimerData timer;
     int ret = 0;
     uint64_t tmp = 0x0ULL;
-    bstring tag = bfromcstralloc(100, regionTag);
-    LikwidThreadResults* results;
-    char groupSuffix[10];
-    sprintf(groupSuffix, "-%d", groupSet->activeGroup);
-    bcatcstr(tag, groupSuffix);
+    LikwidThreadResults* results = NULL;
+    bstring tag = bformat("%.*s-%d", 100, regionTag, groupSet->activeGroup);
     int cpu_id = hashTable_get(tag, &results);
     bdestroy(tag);
+    if (!results)
+    {
+        fprintf(stderr, "ERROR: Failed to get thread data for tag %s\n", regionTag);
+        return -EFAULT;
+    }
 
 #ifndef LIKWID_USE_PERFEVENT
     // Add CPU to access layer if ACCESSMODE is direct or accessdaemon
@@ -532,6 +535,7 @@ likwid_markerRegisterRegion(const char* regionTag)
 int
 likwid_markerStartRegion(const char* regionTag)
 {
+    LikwidThreadResults* results = NULL;
     if ( ! likwid_init )
     {
         return -EFAULT;
@@ -542,13 +546,13 @@ likwid_markerStartRegion(const char* regionTag)
         return -EFAULT;
     }
 
-    bstring tag = bfromcstralloc(100, regionTag);
-    LikwidThreadResults* results;
-    char groupSuffix[10];
-    sprintf(groupSuffix, "-%d", groupSet->activeGroup);
-    bcatcstr(tag, groupSuffix);
-
+    bstring tag = bformat("%.*s-%d", 100, regionTag, groupSet->activeGroup);
     int cpu_id = hashTable_get(tag, &results);
+    if (!results)
+    {
+        fprintf(stderr, "ERROR: Failed to get thread data for tag %s\n", regionTag);
+        return -EFAULT;
+    }
     int thread_id = getThreadID(cpu_id);
     if (results->state == MARKER_STATE_START)
     {
@@ -591,6 +595,7 @@ likwid_markerStopRegion(const char* regionTag)
     }
 
     TimerData timestamp;
+    LikwidThreadResults* results = NULL;
     timer_stop(&timestamp);
     double result = 0.0;
     int cpu_id;
@@ -600,17 +605,22 @@ likwid_markerStopRegion(const char* regionTag)
         return -EFAULT;
     }
     int thread_id;
-    bstring tag = bfromcstr(regionTag);
-    char groupSuffix[100];
-    LikwidThreadResults* results;
-    sprintf(groupSuffix, "-%d", groupSet->activeGroup);
-    bcatcstr(tag, groupSuffix);
+    bstring tag = bformat("%.*s-%d", 100, regionTag, groupSet->activeGroup);
     if (use_locks == 1)
     {
         pthread_mutex_lock(&threadLocks[myCPU]);
     }
 
     cpu_id = hashTable_get(tag, &results);
+    if (!results)
+    {
+        fprintf(stderr, "ERROR: Failed to get thread data for tag %s\n", regionTag);
+        if (use_locks == 1)
+        {
+            pthread_mutex_unlock(&threadLocks[myCPU]);
+        }
+        return -EFAULT;
+    }
     thread_id = getThreadID(cpu_id);
     if (results->state != MARKER_STATE_START)
     {
@@ -682,13 +692,15 @@ likwid_markerGetRegion(
     int cpu_id;
     int myCPU = likwid_getProcessorId();
     int thread_id;
-    bstring tag = bfromcstr(regionTag);
-    char groupSuffix[100];
-    LikwidThreadResults* results;
-    sprintf(groupSuffix, "-%d", groupSet->activeGroup);
-    bcatcstr(tag, groupSuffix);
+    LikwidThreadResults* results = NULL;
+    bstring tag = bformat("%.*s-%d", 100, regionTag, groupSet->activeGroup);
 
     cpu_id = hashTable_get(tag, &results);
+    if (!results)
+    {
+        fprintf(stderr, "ERROR: Failed to get thread data for tag %s\n", regionTag);
+        return;
+    }
     thread_id = getThreadID(myCPU);
     if (count != NULL)
     {
@@ -715,6 +727,7 @@ likwid_markerGetRegion(
 int
 likwid_markerResetRegion(const char* regionTag)
 {
+    LikwidThreadResults* results = NULL;
     if (! likwid_init)
     {
         return -EFAULT;
@@ -725,13 +738,14 @@ likwid_markerResetRegion(const char* regionTag)
     {
         return -EFAULT;
     }
-    bstring tag = bfromcstr(regionTag);
-    char groupSuffix[100];
-    LikwidThreadResults* results;
-    sprintf(groupSuffix, "-%d", groupSet->activeGroup);
-    bcatcstr(tag, groupSuffix);
+    bstring tag = bformat("%.*s-%d", 100, regionTag, groupSet->activeGroup);
 
     cpu_id = hashTable_get(tag, &results);
+    if (!results)
+    {
+        fprintf(stderr, "ERROR: Failed to get thread data for tag %s\n", regionTag);
+        return -EFAULT;
+    }
     if (results->state != MARKER_STATE_STOP)
     {
         fprintf(stderr, "ERROR: Can only reset stopped regions\n");
diff --git a/src/perfmon.c b/src/perfmon.c
index de3a2ba8e..7dc0d5372 100644
--- a/src/perfmon.c
+++ b/src/perfmon.c
@@ -3903,7 +3903,7 @@ perfmon_readMarkerFile(const char* filename)
         if (strchr(buf,':'))
         {
             int regionid = 0, groupid = -1;
-            char regiontag[100];
+            char regiontag[140];
             char* ptr = NULL;
             char* colonptr = NULL;
             // zero out ALL of regiontag due to replacing %s with %Nc