ch4/ofi: Remove unused globals for striping and hashing

There is no use for these global variables tracking the number of
communicators with striping or hashing enabled. ThreadSanitizer
correctly flagged their accesses as racey. Remove them.

Author: raffenet

src/mpid/ch4/netmod/ofi/ofi_comm.c

@@ -17,8 +17,6 @@ static int update_multi_nic_hints(MPIR_Comm * comm)
     if (comm) {
         /* If the user set a multi-nic hint, but num_nics = 1, disable multi-nic optimizations. */
         if (MPIDI_OFI_global.num_nics > 1) {
-            int was_enabled_striping = MPIDI_OFI_COMM(comm).enable_striping;
-
             /* Check if we should use striping */
             if (HAS_PREF_NIC(comm)) {
                 /* If the user specified a particular NIC, don't use striping. */
@@ -29,19 +27,10 @@ static int update_multi_nic_hints(MPIR_Comm * comm)
             else
                 MPIDI_OFI_COMM(comm).enable_striping = MPIR_CVAR_CH4_OFI_ENABLE_MULTI_NIC_STRIPING;
 
-            /* If striping was on and we disabled it here, decrement the global counter. */
-            if (was_enabled_striping > 0 && MPIDI_OFI_COMM(comm).enable_striping == 0)
-                MPIDI_OFI_global.num_comms_enabled_striping--;
-            /* If striping was off and we enabled it here, increment the global counter. */
-            else if (was_enabled_striping <= 0 && MPIDI_OFI_COMM(comm).enable_striping != 0)
-                MPIDI_OFI_global.num_comms_enabled_striping++;
-
             if (MPIDI_OFI_COMM(comm).enable_striping) {
                 MPIDI_OFI_global.stripe_threshold = MPIR_CVAR_CH4_OFI_MULTI_NIC_STRIPING_THRESHOLD;
             }
 
-            int was_enabled_hashing = MPIDI_OFI_COMM(comm).enable_hashing;
-
             /* Check if we should use hashing */
             if (HAS_PREF_NIC(comm)) {
                 /* If the user specified a particular NIC, don't use hashing.  */
@@ -60,13 +49,6 @@ static int update_multi_nic_hints(MPIR_Comm * comm)
                  !comm->hints[MPIR_COMM_HINT_NO_ANY_SOURCE])) {
                 MPIDI_OFI_COMM(comm).enable_hashing = 0;
             }
-
-            /* If hashing was on and we disabled it here, decrement the global counter. */
-            if (was_enabled_hashing > 0 && MPIDI_OFI_COMM(comm).enable_hashing == 0)
-                MPIDI_OFI_global.num_comms_enabled_hashing--;
-            /* If hashing was off and we enabled it here, increment the global counter. */
-            else if (was_enabled_hashing <= 0 && MPIDI_OFI_COMM(comm).enable_hashing != 0)
-                MPIDI_OFI_global.num_comms_enabled_hashing++;
         }
     }
 
@@ -145,8 +127,6 @@ int MPIDI_OFI_mpi_comm_commit_pre_hook(MPIR_Comm * comm)
     MPIDI_OFI_COMM(comm).conn_id = -1;
 
     /* Initialize the multi-nic optimization values */
-    MPIDI_OFI_global.num_comms_enabled_striping = 0;
-    MPIDI_OFI_global.num_comms_enabled_hashing = 0;
     MPIDI_OFI_COMM(comm).enable_striping = 0;
     MPIDI_OFI_COMM(comm).enable_hashing = 0;
     MPIDI_OFI_COMM(comm).pref_nic = NULL;
@@ -192,12 +172,6 @@ int MPIDI_OFI_mpi_comm_free_hook(MPIR_Comm * comm)
     int mpi_errno = MPI_SUCCESS;
     MPIR_FUNC_ENTER;
 
-    /* If we enabled striping or hashing, decrement the counter. */
-    MPIDI_OFI_global.num_comms_enabled_striping -=
-        (MPIDI_OFI_COMM(comm).enable_striping != 0 ? 1 : 0);
-    MPIDI_OFI_global.num_comms_enabled_hashing -=
-        (MPIDI_OFI_COMM(comm).enable_hashing != 0 ? 1 : 0);
-
     MPL_free(MPIDI_OFI_COMM(comm).pref_nic);
 
     MPIR_FUNC_EXIT;

src/mpid/ch4/netmod/ofi/ofi_init.c

@@ -644,9 +644,6 @@ int MPIDI_OFI_init_local(int *tag_bits)
     /* Initialize RMA keys allocator */
     MPIDI_OFI_mr_key_allocator_init();
 
-    MPIDI_OFI_global.num_comms_enabled_striping = 0;
-    MPIDI_OFI_global.num_comms_enabled_hashing = 0;
-
     mpi_errno = ofi_pvar_init();
     MPIR_ERR_CHECK(mpi_errno);
 

src/mpid/ch4/netmod/ofi/ofi_types.h

@@ -489,8 +489,6 @@ typedef struct {
     MPIDI_OFI_per_vci_t per_vci[MPIDI_CH4_MAX_VCIS];
     int num_vcis;
     int num_nics;
-    int num_comms_enabled_striping;     /* Number of active communicators with striping enabled */
-    int num_comms_enabled_hashing;      /* Number of active communicators with hashingenabled */
     bool am_bufs_registered;    /* whether active message buffers are GPU registered */
 
     /* Window/RMA Globals */