diff --git a/comex/src-mpi-pr/comex.c b/comex/src-mpi-pr/comex.c
index f485798a..ae2306ef 100644
--- a/comex/src-mpi-pr/comex.c
+++ b/comex/src-mpi-pr/comex.c
@@ -2722,8 +2722,8 @@ int comex_malloc_mem_dev(void *ptrs[], size_t size, comex_group_t group,
                 reg_entries_local[reg_entries_local_count++] = reg_entries[i];
             }
         }
-        else if (g_state.hostid[reg_entries[i].rank]
-                == g_state.hostid[my_world_rank]) {
+        else if (!strcmp(g_state.host[reg_entries[i].rank].name,
+                g_state.host[my_world_rank].name)) {
             /* same SMP node, need to mmap */
             /* open remote shared memory object */
             void *memory = _shm_attach_memdev(reg_entries[i].name,
@@ -2880,7 +2880,7 @@ void _malloc_semaphore()
         if (g_state.rank == i) {
             continue; /* skip my own rank */
         }
-        else if (g_state.hostid[g_state.rank] == g_state.hostid[i]) {
+        else if (!strcmp(g_state.host[g_state.rank].name,g_state.host[i].name)) {
             /* same SMP node */
 #if ENABLE_UNNAMED_SEM
             semaphores[i] = _shm_attach(
@@ -2949,7 +2949,7 @@ void _free_semaphore()
             }
 #endif
         }
-        else if (g_state.hostid[g_state.rank] == g_state.hostid[i]) {
+        else if (!strcmp(g_state.host[g_state.rank].name,g_state.host[i].name)) {
             /* same SMP node */
 #if ENABLE_UNNAMED_SEM
             retval = munmap(semaphores[i], sizeof(sem_t));
@@ -4648,8 +4648,8 @@ STATIC void _malloc_handler(
             fprintf(stderr, "[%d] _malloc_handler found NULL at %d\n", g_state.rank, i);
 #endif
         }
-        else if (g_state.hostid[reg_entries[i].rank]
-                == g_state.hostid[g_state.rank]) {
+        else if (!strcmp(g_state.host[reg_entries[i].rank].name,
+                g_state.host[g_state.rank].name)) {
             /* same SMP node, need to mmap */
             /* attach to remote shared memory object */
           void *memory;
@@ -4741,8 +4741,8 @@ STATIC void _free_handler(header_t *header, char *payload, int proc)
             fprintf(stderr, "[%d] _free_handler found NULL at %d\n", g_state.rank, i);
 #endif
         }
-        else if (g_state.hostid[rank_ptrs[i].rank]
-                == g_state.hostid[g_state.rank]) {
+        else if (!strcmp(g_state.host[rank_ptrs[i].rank].name,
+                g_state.host[g_state.rank].name)) {
             /* same SMP node */
             reg_entry_t *reg_entry = NULL;
             int retval = 0;
@@ -4926,7 +4926,7 @@ STATIC int _smallest_world_rank_with_same_hostid(comex_igroup_t *igroup)
     int *world_ranks = _get_world_ranks(igroup);
 
     for (i=0; i<igroup->size; ++i) {
-        if (g_state.hostid[world_ranks[i]] == g_state.hostid[g_state.rank]) {
+        if (!strcmp(g_state.host[world_ranks[i]].name,g_state.host[g_state.rank].name)) {
             /* found same host as me */
             if (world_ranks[i] < smallest) {
                 smallest = world_ranks[i];
@@ -4949,7 +4949,7 @@ STATIC int _largest_world_rank_with_same_hostid(comex_igroup_t *igroup)
     int *world_ranks = _get_world_ranks(igroup);
 
     for (i=0; i<igroup->size; ++i) {
-        if (g_state.hostid[world_ranks[i]] == g_state.hostid[g_state.rank]) {
+        if (!strcmp(g_state.host[world_ranks[i]].name,g_state.host[g_state.rank].name)) {
             /* found same host as me */
             if (world_ranks[i] > largest) {
                 largest = world_ranks[i];
@@ -6365,7 +6365,7 @@ STATIC void nb_puts(
     if (COMEX_ENABLE_PUT_DATATYPE
             && (!COMEX_ENABLE_PUT_SELF || g_state.rank != proc)
             && (!COMEX_ENABLE_PUT_SMP
-                || g_state.hostid[proc] != g_state.hostid[g_state.rank])
+                || strcmp(g_state.host[proc].name,g_state.host[g_state.rank].name))
             && (_packed_size(src_stride, count, stride_levels) > COMEX_PUT_DATATYPE_THRESHOLD)) {
         nb_puts_datatype(src, src_stride, dst, dst_stride, count, stride_levels, proc, nb);
         return;
@@ -6375,7 +6375,7 @@ STATIC void nb_puts(
     if (COMEX_ENABLE_PUT_PACKED
             && (!COMEX_ENABLE_PUT_SELF || g_state.rank != proc)
             && (!COMEX_ENABLE_PUT_SMP
-                || g_state.hostid[proc] != g_state.hostid[g_state.rank])) {
+                || strcmp(g_state.host[proc].name,g_state.host[g_state.rank].name))) {
         nb_puts_packed(src, src_stride, dst, dst_stride, count, stride_levels, proc, nb);
         return;
     }
@@ -6634,7 +6634,7 @@ STATIC void nb_gets(
     if (COMEX_ENABLE_GET_DATATYPE
             && (!COMEX_ENABLE_GET_SELF || g_state.rank != proc)
             && (!COMEX_ENABLE_GET_SMP
-                || g_state.hostid[proc] != g_state.hostid[g_state.rank])
+                || strcmp(g_state.host[proc].name,g_state.host[g_state.rank].name))
             && (_packed_size(src_stride, count, stride_levels) > COMEX_GET_DATATYPE_THRESHOLD)) {
         nb_gets_datatype(src, src_stride, dst, dst_stride, count, stride_levels, proc, nb);
         return;
@@ -6644,7 +6644,7 @@ STATIC void nb_gets(
     if (COMEX_ENABLE_GET_PACKED
             && (!COMEX_ENABLE_GET_SELF || g_state.rank != proc)
             && (!COMEX_ENABLE_GET_SMP
-                || g_state.hostid[proc] != g_state.hostid[g_state.rank])) {
+                || strcmp(g_state.host[proc].name,g_state.host[g_state.rank].name))) {
         nb_gets_packed(src, src_stride, dst, dst_stride, count, stride_levels, proc, nb);
         return;
     }
@@ -6910,7 +6910,7 @@ STATIC void nb_accs(
     if (COMEX_ENABLE_ACC_PACKED
             && (!COMEX_ENABLE_ACC_SELF || g_state.rank != proc)
             && (!COMEX_ENABLE_ACC_SMP
-                || g_state.hostid[proc] != g_state.hostid[g_state.rank])) {
+                || strcmp(g_state.host[proc].name,g_state.host[g_state.rank].name))) {
         nb_accs_packed(datatype, scale, src, src_stride, dst, dst_stride, count, stride_levels, proc, nb);
         return;
     }
@@ -7120,7 +7120,7 @@ STATIC void nb_putv(
         if (COMEX_ENABLE_PUT_IOV
                 && (!COMEX_ENABLE_PUT_SELF || g_state.rank != proc)
                 && (!COMEX_ENABLE_PUT_SMP
-                    || g_state.hostid[proc] != g_state.hostid[g_state.rank])) {
+                    || strcmp(g_state.host[proc].name,g_state.host[g_state.rank].name))) {
             nb_putv_packed(&iov[i], proc, nb);
         }
         else {
@@ -7224,7 +7224,7 @@ STATIC void nb_getv(
         if (COMEX_ENABLE_GET_IOV
                 && (!COMEX_ENABLE_GET_SELF || g_state.rank != proc)
                 && (!COMEX_ENABLE_GET_SMP
-                    || g_state.hostid[proc] != g_state.hostid[g_state.rank])) {
+                    || strcmp(g_state.host[proc].name,g_state.host[g_state.rank].name))) {
             nb_getv_packed(&iov[i], proc, nb);
         }
         else {
@@ -7336,7 +7336,7 @@ STATIC void nb_accv(
         if (COMEX_ENABLE_ACC_IOV
                 && (!COMEX_ENABLE_ACC_SELF || g_state.rank != proc)
                 && (!COMEX_ENABLE_ACC_SMP
-                    || g_state.hostid[proc] != g_state.hostid[g_state.rank])) {
+                    || strcmp(g_state.host[proc].name,g_state.host[g_state.rank].name))) {
             nb_accv_packed(datatype, scale, &iov[i], proc, nb);
         }
         else {
diff --git a/comex/src-mpi-pr/groups.c b/comex/src-mpi-pr/groups.c
index aa49233c..6ecbf73a 100644
--- a/comex/src-mpi-pr/groups.c
+++ b/comex/src-mpi-pr/groups.c
@@ -381,6 +381,27 @@ static int cmplong(const void *p1, const void *p2)
     return *((long*)p1) - *((long*)p2);
 }
 
+static int cmpname(const void *name1, const void *name2)
+{
+  const char* n1 = (const char*)name1;
+  const char* n2 = (const char*)name2;
+  int comp = 0;
+  int i;
+  for (i=0; i<COMEX_MAX_HOST_NAME_LEN; i++) {
+    if ((int)n1[i] < (int)n2[i]) {
+      comp = -1;
+      break;
+    } else if ((int)n1[i] > (int)n2[i]) {
+      comp = 1;
+      break;
+    } else if (n1[i] == '\0' || n2[i] == '\0') {
+      break;
+    }
+  }
+  return comp;
+}
+
+
 /**
  * Initialize group linked list. Prepopulate with world group.
  */
@@ -393,7 +414,7 @@ void comex_group_init(MPI_Comm comm)
     int size_node = 0;
     comex_group_t group = 0;
     comex_igroup_t *igroup = NULL;
-    long *sorted = NULL;
+    host_name_t *sorted = NULL;
     int count = 0;
     
     /* populate g_state */
@@ -420,10 +441,10 @@ void comex_group_init(MPI_Comm comm)
 #endif
 
     /* need to figure out which proc is master on each node */
-    g_state.hostid = (long*)malloc(sizeof(long)*g_state.size);
-    g_state.hostid[g_state.rank] = xgethostid();
-    status = MPI_Allgather(MPI_IN_PLACE, 1, MPI_LONG,
-            g_state.hostid, 1, MPI_LONG, g_state.comm);
+    g_state.host = (host_name_t*)malloc(sizeof(host_name_t)*g_state.size);
+    gethostname(g_state.host[g_state.rank].name,COMEX_MAX_HOST_NAME_LEN);
+    status = MPI_Allgather(MPI_IN_PLACE, sizeof(host_name_t), MPI_BYTE,
+            g_state.host, sizeof(host_name_t), MPI_BYTE, g_state.comm);
     COMEX_ASSERT(MPI_SUCCESS == status);
      /* First create a temporary node communicator and then
       * split further into number of groups within the node */
@@ -432,17 +453,17 @@ void comex_group_init(MPI_Comm comm)
     /* create node comm */
     /* MPI_Comm_split requires a non-negative color,
      * so sort and sanitize */
-    sorted = (long*)malloc(sizeof(long) * g_state.size);
-    (void)memcpy(sorted, g_state.hostid, sizeof(long)*g_state.size);
-    qsort(sorted, g_state.size, sizeof(long), cmplong);
+    sorted = (long*)malloc(sizeof(host_name_t) * g_state.size);
+    (void)memcpy(sorted, g_state.host, sizeof(host_name_t)*g_state.size);
+    qsort(sorted, g_state.size, sizeof(host_name_t), cmpname);
     /* count is number of distinct host IDs that are lower than
      * the host ID of this rank */
     for (i=0; i<g_state.size-1; ++i) {
-        if (sorted[i] == g_state.hostid[g_state.rank]) 
+        if (!strcmp(sorted[i].name,g_state.host[g_state.rank].name)) 
         {
             break;
         }
-        if (sorted[i] != sorted[i+1]) {
+        if (strcmp(sorted[i].name,sorted[i+1].name)) {
             count += 1;
         }
     }
@@ -463,7 +484,7 @@ void comex_group_init(MPI_Comm comm)
     smallest_rank_with_same_hostid = g_state.rank;
     largest_rank_with_same_hostid = g_state.rank;
     for (i=0; i<g_state.size; ++i) {
-        if (g_state.hostid[i] == g_state.hostid[g_state.rank]) {
+        if (!strcmp(g_state.host[i].name,g_state.host[g_state.rank].name)) {
             ++size_node;
             if (i < smallest_rank_with_same_hostid) {
                 smallest_rank_with_same_hostid = i;
@@ -605,7 +626,7 @@ void comex_group_finalize()
     }
 
     free(g_state.master);
-    free(g_state.hostid);
+    free(g_state.host);
     status = MPI_Comm_free(&(g_state.node_comm));
     COMEX_ASSERT(MPI_SUCCESS == status);
     status = MPI_Group_free(&(g_state.group));
diff --git a/comex/src-mpi-pr/groups.h b/comex/src-mpi-pr/groups.h
index 33339d0e..613b159c 100644
--- a/comex/src-mpi-pr/groups.h
+++ b/comex/src-mpi-pr/groups.h
@@ -8,17 +8,23 @@
 #ifndef _COMEX_GROUPS_H_
 #define _COMEX_GROUPS_H_
 
+#define COMEX_MAX_HOST_NAME_LEN 256
+
 #include <mpi.h>
 
 #include "comex.h"
 
+typedef struct {
+  char name[COMEX_MAX_HOST_NAME_LEN];
+} host_name_t;
+
 typedef struct {
     MPI_Comm comm;  /**< whole comm; all ranks */
     MPI_Group group;/**< whole group; all ranks */
     int size;       /**< comm size */
     int rank;       /**< comm rank */
     int *master;    /**< master[size] rank of a given rank's master */
-    long *hostid;   /**< hostid[size] hostid of SMP node for a given rank */
+    host_name_t *host;   /**< host[size] host name of SMP node for a given rank */
     MPI_Comm node_comm;  /**< node comm; SMP ranks */
     int node_size;       /**< node comm size */
     int node_rank;       /**< node comm rank */