[dcmf] [PATCH 1/1] Issue 4362: Honor the romio_ds_write and romio_ds_read hints.

[Bob Cernohous]

We received this request:

 The ROMIO implementation used on BG/P performs some optimization using
 data sieving for non-continuous individual I/O. This is done using
 read-modify-write operations that rely on file locking. This fails for
 PVFS because PVFS is lockless. The easiest solution would to make
 ADIOI_BGL_WriteStrided honor the romio_ds_write hint and fall back to
 ADIOI_GEN_WriteStrided_naive.

We now honor those hints and fall back to the GEN naive write/read routines.

It has only been tested in so far as it does run the GEN code when requested.
We have not tested, and will not attempt to test, PVFS.

Signed-off-by: Bob Cernohous <bobc at us.ibm.com>
---
 .../mpich2/src/mpi/romio/adio/ad_bgl/ad_bgl_read.c |   19 ++++++++++++++++++-
 .../src/mpi/romio/adio/ad_bgl/ad_bgl_write.c       |   19 ++++++++++++++++++-
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/lib/mpi/mpich2/src/mpi/romio/adio/ad_bgl/ad_bgl_read.c b/lib/mpi/mpich2/src/mpi/romio/adio/ad_bgl/ad_bgl_read.c
index a3aeffb..41947c9 100644
--- a/lib/mpi/mpich2/src/mpi/romio/adio/ad_bgl/ad_bgl_read.c
+++ b/lib/mpi/mpich2/src/mpi/romio/adio/ad_bgl/ad_bgl_read.c
@@ -29,10 +29,10 @@ void ADIOI_BGL_ReadContig(ADIO_File fd, void *buf, int count,
     int err=-1, datatype_size, len;
     static char myname[] = "ADIOI_BGL_READCONTIG";
 
+#if BGL_PROFILE
 		/* timing */
 		double io_time, io_time2;
 
-#if BGL_PROFILE
 		if (bglmpio_timing) {
 		    io_time = MPI_Wtime();
 		    bglmpio_prof_cr[ BGLMPIO_CIO_DATA_SIZE ] += len;
@@ -181,6 +181,23 @@ void ADIOI_BGL_ReadStrided(ADIO_File fd, void *buf, int count,
 
     static char myname[] = "ADIOI_BGL_READSTRIDED";
 
+    if (fd->hints->ds_read == ADIOI_HINT_DISABLE) {
+  /* if user has disabled data sieving on reads, use naive
+	 * approach instead.
+	 */
+      /*FPRINTF(stderr, "ADIOI_GEN_ReadStrided_naive(%d):\n", __LINE__);*/
+      ADIOI_GEN_ReadStrided_naive(fd, 
+				    buf,
+				    count,
+				    datatype,
+				    file_ptr_type,
+				    offset,
+				    status,
+				    error_code);
+    	return;
+    }
+    /*FPRINTF(stderr, "%s(%d):\n",myname, __LINE__);*/
+
     ADIOI_Datatype_iscontig(datatype, &buftype_is_contig);
     ADIOI_Datatype_iscontig(fd->filetype, &filetype_is_contig);
 
diff --git a/lib/mpi/mpich2/src/mpi/romio/adio/ad_bgl/ad_bgl_write.c b/lib/mpi/mpich2/src/mpi/romio/adio/ad_bgl/ad_bgl_write.c
index a74d0a9..6fbdb20 100644
--- a/lib/mpi/mpich2/src/mpi/romio/adio/ad_bgl/ad_bgl_write.c
+++ b/lib/mpi/mpich2/src/mpi/romio/adio/ad_bgl/ad_bgl_write.c
@@ -29,10 +29,10 @@ void ADIOI_BGL_WriteContig(ADIO_File fd, void *buf, int count,
     int err=-1, datatype_size, len;
     static char myname[] = "ADIOI_BGL_WRITECONTIG";
 
+#if BGL_PROFILE
 		/* timing */
 		double io_time, io_time2;
 
-#if BGL_PROFILE
 		if (bglmpio_timing) { 
 		    io_time = MPI_Wtime(); 
 		    bglmpio_prof_cw[ BGLMPIO_CIO_DATA_SIZE ] += len;
@@ -221,6 +221,23 @@ void ADIOI_BGL_WriteStrided(ADIO_File fd, void *buf, int count,
     int new_bwr_size, new_fwr_size, err_flag=0, info_flag, max_bufsize;
     static char myname[] = "ADIOI_BGL_WRITESTRIDED";
 
+    if (fd->hints->ds_write == ADIOI_HINT_DISABLE) {
+    	/* if user has disabled data sieving on reads, use naive
+	 * approach instead.
+	 */
+      /*FPRINTF(stderr, "ADIOI_GEN_WriteStrided_naive(%d):\n", __LINE__);*/
+      ADIOI_GEN_WriteStrided_naive(fd, 
+				    buf,
+				    count,
+				    datatype,
+				    file_ptr_type,
+				    offset,
+				    status,
+				    error_code);
+    	return;
+    }
+    /*FPRINTF(stderr, "%s(%d):\n",myname, __LINE__);*/
+
     ADIOI_Datatype_iscontig(datatype, &buftype_is_contig);
     ADIOI_Datatype_iscontig(fd->filetype, &filetype_is_contig);
 
-- 
1.5.3.7