* Add memory barriers for shared memory. Rich and I think we got them

all and the Intel tests pass slightly oversubscribed.

This commit was SVN r7431.

README

@@ -60,13 +60,6 @@ base as of this writing (26 Aug 2005):
 
 - LAM/MPI-like mpirun notation of "C" and "N" is not yet supported.
 
-- Shared memory support will not function properly on machines that
-  have a weak memory consistency mode.  The default in this beta is to
-  disable shared memory support on all Power PC architectures, even
-  though some Power PC platforms have strong memory consistency
-  models.  See the description of the --enable-ptl-sm configure flag,
-  below.
-
 - Striping MPI messages across multiple networks is supported (and
   happens automatically when multiple networks are available), but
   needs performance tuning.

ompi/class/ompi_circular_buffer_fifo.h

@@ -18,9 +18,9 @@
 #define _OMPI_CIRCULAR_BUFFER_FIFO
 
 #include "ompi/include/constants.h"
-#include "include/sys/cache.h"
+#include "opal/include/sys/cache.h"
-#include "include/sys/atomic.h"
+#include "opal/include/sys/atomic.h"
-#include "mca/mpool/mpool.h"
+#include "ompi/mca/mpool/mpool.h"
 #include "opal/util/pow2.h"
 
 
@@ -304,6 +304,7 @@ static inline int ompi_cb_fifo_write_to_head(void *data, ompi_cb_fifo_t
     if (ptr[index] == OMPI_CB_FREE) {
         slot = index;
         ptr[slot] = data;
+        opal_atomic_wmb();
         (h_ptr->fifo_index)++;
         (h_ptr->fifo_index) &= fifo->mask;
     }
@@ -337,6 +338,7 @@ static inline int ompi_cb_fifo_get_slot(ompi_cb_fifo_t *fifo,
     if ( OMPI_CB_FREE == ptr[index] ) {
         ptr[index] = OMPI_CB_RESERVED;
         return_value = index;
+        opal_atomic_wmb();
         (h_ptr->fifo_index)++;
         (h_ptr->fifo_index) &= fifo->mask;
     }
@@ -622,6 +624,7 @@ static inline int ompi_cb_fifo_write_to_head_same_base_addr(void *data, ompi_cb_
     if (ptr[index] == OMPI_CB_FREE) {
         slot = index;
         ptr[slot] = data;
+        opal_atomic_wmb();
         (h_ptr->fifo_index)++;
         /* wrap around */
         (h_ptr->fifo_index) &= fifo->mask;
@@ -655,6 +658,7 @@ static inline int ompi_cb_fifo_get_slot_same_base_addr(ompi_cb_fifo_t *fifo)
     if ( OMPI_CB_FREE == ptr[index] ) {
         ptr[index] = OMPI_CB_RESERVED;
         return_value = index;
+        opal_atomic_wmb();
         (h_ptr->fifo_index)++;
         (h_ptr->fifo_index) &= fifo->mask;
     }

ompi/mca/btl/sm/btl_sm.c

@@ -433,8 +433,8 @@ int mca_btl_sm_add_procs_same_base_addr(
         fifo_tmp=(ompi_fifo_t * volatile *)
                 ( (char *)(mca_btl_sm_component.sm_ctl_header->fifo) +
                   (long)(mca_btl_sm_component.sm_mpool->mpool_base(mca_btl_sm_component.sm_mpool)) );
-        /* RLG : need memory barrier */
         fifo_tmp[mca_btl_sm_component.my_smp_rank]=my_fifos;
+        opal_atomic_mb();
 
         /* cache the pointer to the 2d fifo array.  These addresses
          * are valid in the current process space */