[svn-r5861] ./hdf5-devel/src/H5FDmpiposix.c

Purpose:
    Merged from 1.4 branch
Description:
    API tracing improvements
Platforms tested:
    Linux (--disable-hsizet didn't work before my changes and still doesn't
    work, but --enable-hsizet is fine).



Note: This checkin includes temporary code in H5FDmpiposix.c to turn
off GPFS byte range token prefetches on ASCI/Blue.  Once the HDF5 API
supports the necessary prerequisite functionality this temporary code
can be migraged up above HDF5.

1 files changed, 35 insertions, 0 deletions

diff --git a/src/H5FDmpiposix.c b/src/H5FDmpiposix.c
index 117fea7..e7c5284 100644
--- a/src/H5FDmpiposix.c
+++ b/src/H5FDmpiposix.c
@@ -41,6 +41,10 @@
 #include "H5MMprivate.h"        /*memory allocation                     */
 #include "H5Pprivate.h"		/*property lists			*/
 
+#ifdef USE_GPFS_HINTS
+#   include <gpfs_fcntl.h>
+#endif
+
 /*
  * The driver identification number, initialized at runtime if H5_HAVE_PARALLEL
  * is defined. This allows applications to still have the H5FD_MPIPOSIX
@@ -604,6 +608,37 @@ H5FD_mpiposix_open(const char *name, unsigned flags, hid_t fapl_id,
     if (MPI_SUCCESS != (mpi_code= MPI_Bcast(&sb, sizeof(h5_stat_t), MPI_BYTE, 0, fa->comm)))
         HMPI_GOTO_ERROR(NULL, "MPI_Bcast failed", mpi_code);
 
+#ifdef USE_GPFS_HINTS
+    /* Prevent GPFS from prefetching byte range (BR) tokens */
+    {
+        struct {
+            gpfsFcntlHeader_t   hdr;
+            gpfsFreeRange_t     fr;
+            gpfsMultipleAccessRange_t mar;
+        } hint;
+        memset(&hint, 0, sizeof hint);
+        hint.hdr.totalLength = sizeof hint;
+        hint.hdr.fcntlVersion = GPFS_FCNTL_CURRENT_VERSION;
+        hint.fr.structLen = sizeof hint.fr;
+        hint.fr.structType = GPFS_FREE_RANGE;
+        hint.fr.start = 0;
+        hint.fr.length = 0;
+        hint.mar.structLen = sizeof hint.mar;
+        hint.mar.structType = GPFS_MULTIPLE_ACCESS_RANGE;
+        hint.mar.accRangeCnt = 1;
+        hint.mar.accRangeArray[0].blockNumber = 1 + mpi_rank;
+        hint.mar.accRangeArray[0].start = 0;
+        hint.mar.accRangeArray[0].length = sb.st_blksize;
+        hint.mar.accRangeArray[0].isWrite = true;
+        
+        if (gpfs_fcntl(f->fd, &hint)<0)
+            HGOTO_ERROR(H5E_FILE, H5E_FCNTL, NULL, "failed to send hints to GPFS");
+
+        if (0==mpi_rank)
+            fprintf(stderr, "HDF5: using GPFS hint mechanism...\n");
+    }
+#endif
+
     /* Build the file struct and initialize it */
     if (NULL==(file=H5MM_calloc(sizeof(H5FD_mpiposix_t))))
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");