diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index f9547f3281..b8619148c9 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -362,6 +362,19 @@ Bug Fixes since HDF5-1.10.3 release
 
     Library
     -------
+    - Fixed the slowness of regular hyperslab selection in a chunked dataset
+
+      It was reported that the selection of every 10th element from a 20G
+      chunked dataset was extremely slow and sometimes could hang the system.
+      The problem was due to the iteration and the building of the span tree
+      for all the selected elements in file space.
+
+      As the selected elements are going to a 1-d contiguous single block
+      memory space, the problem was fixed by building regular hyperslab selections
+      in memory space for the selected elements in file space.
+
+      (VC - 2019/09/26, HDFFV-10585)
+
     - Fixed a bug caused by bad tag value when condensing object header
       messages
 
diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 7154d0b476..ed82b3b274 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -255,7 +255,7 @@ static herr_t H5D__chunk_io_init(const H5D_io_info_t *io_info,
     const H5D_type_info_t *type_info, hsize_t nelmts, const H5S_t *file_space,
     const H5S_t *mem_space, H5D_chunk_map_t *fm);
 static herr_t H5D__chunk_io_init_selections(const H5D_io_info_t *io_info, 
-    const H5D_type_info_t *type_info, hsize_t nelmts, H5D_chunk_map_t *fm);
+    const H5D_type_info_t *type_info, H5D_chunk_map_t *fm);
 static herr_t H5D__chunk_read(H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
     hsize_t nelmts, const H5S_t *file_space, const H5S_t *mem_space,
     H5D_chunk_map_t *fm);
@@ -1160,7 +1160,7 @@ H5D__chunk_io_init(const H5D_io_info_t *io_info, const H5D_type_info_t *type_inf
     fm->file_space = file_space;
     fm->mem_space = mem_space;
 
-    if(H5D__chunk_io_init_selections(io_info, type_info, nelmts, fm) < 0)
+    if(H5D__chunk_io_init_selections(io_info, type_info, fm) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to create file and memory chunk selections")
 
 done:
@@ -1189,8 +1189,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D__chunk_io_init_selections(const H5D_io_info_t *io_info, const H5D_type_info_t *type_info,
-    hsize_t nelmts, H5D_chunk_map_t *fm)
+H5D__chunk_io_init_selections(const H5D_io_info_t *io_info, const H5D_type_info_t *type_info, H5D_chunk_map_t *fm)
 {
     const H5D_t *dataset = io_info->dset;     /* Local pointer to dataset info */
     const H5T_t *mem_type = type_info->mem_type;        /* Local pointer to memory datatype */
diff --git a/test/tselect.c b/test/tselect.c
index 808704d809..91da4c402b 100644
--- a/test/tselect.c
+++ b/test/tselect.c
@@ -15329,7 +15329,7 @@ test_select_intersect_block(void)
 **  test_hyper_io_1d(): 
 **  Test to verify all the selected 10th element in the 1-d file
 **  dataspace is read correctly into the 1-d contiguous memory space.
-**  This is modeled after the test scenario described in HDFFV-20585
+**  This is modeled after the test scenario described in HDFFV-10585
 **  that demonstrated the hyperslab slowness.  A fix to speed up
 **  performance is in place to handle the special case for 1-d disjoint
 **  file dataspace into 1-d single block contiguous memory space.
@@ -15361,22 +15361,22 @@ test_hyper_io_1d(void)
 
     /* Create the file file */
     fid = H5Fcreate(FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
-    CHECK(fid, FAIL, "H5Fcreate");
+    CHECK(fid, H5I_INVALID_HID, "H5Fcreate");
 
     /* Create file dataspace */
     dims[0] = CHUNKSZ;
     maxdims[0] = H5S_UNLIMITED;
     sid = H5Screate_simple(RANK, dims, maxdims);
-    CHECK(sid, FAIL, "H5Pcreate");
+    CHECK(sid, H5I_INVALID_HID, "H5Pcreate");
 
     /* Create memory dataspace */
     dimsm[0] = CHUNKSZ;
     mid = H5Screate_simple(RANK, dimsm, NULL);
-    CHECK(mid, FAIL, "H5Pcreate");
+    CHECK(mid, H5I_INVALID_HID, "H5Pcreate");
 
     /* Set up to create a chunked dataset */
     dcpl = H5Pcreate(H5P_DATASET_CREATE);
-    CHECK(dcpl, FAIL, "H5Pcreate");
+    CHECK(dcpl, H5I_INVALID_HID, "H5Pcreate");
 
     chunk_dims[0] = CHUNKSZ;
     ret = H5Pset_chunk(dcpl, RANK, chunk_dims);
@@ -15384,7 +15384,7 @@ test_hyper_io_1d(void)
 
     /* Create a chunked dataset */
     did = H5Dcreate2(fid, DNAME, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl, H5P_DEFAULT);
-    CHECK(did, FAIL, "H5Dcreate2");
+    CHECK(did, H5I_INVALID_HID, "H5Dcreate2");
 
     /* Set up hyperslab selection for file dataspace */
     offset[0] = 0;
@@ -15411,7 +15411,7 @@ test_hyper_io_1d(void)
 
             /* Get the dataset's current dataspace */
             sid = H5Dget_space(did);
-            CHECK(sid, FAIL, "H5Dget_space");
+            CHECK(sid, H5I_INVALID_HID, "H5Dget_space");
         }
     }
 
@@ -15429,11 +15429,11 @@ test_hyper_io_1d(void)
 
     /* Open the file */
     fid = H5Fopen(FILENAME, H5F_ACC_RDONLY, H5P_DEFAULT);
-    CHECK(fid, FAIL, "H5Fopen");
+    CHECK(fid, H5I_INVALID_HID, "H5Fopen");
 
     /* Open the dataset */
     did = H5Dopen(fid, DNAME, H5P_DEFAULT);
-    CHECK(did, FAIL, "H5Dopen");
+    CHECK(did, H5I_INVALID_HID, "H5Dopen");
 
     /* Set up to read every 10th element in file dataspace */
     offset[0] = 1;
@@ -15443,14 +15443,14 @@ test_hyper_io_1d(void)
 
     /* Get the dataset's dataspace */
     sid = H5Dget_space(did);
-    CHECK(sid, FAIL, "H5Pcreate");
+    CHECK(sid, H5I_INVALID_HID, "H5Pcreate");
     ret = H5Sselect_hyperslab(sid, H5S_SELECT_SET, offset, stride, count, block);
     CHECK(ret, FAIL, "H5Sselect_hyperslab");
 
     /* Set up contiguous memory dataspace for the selected elements */
     dimsm[0] = count[0];
     mid = H5Screate_simple(RANK, dimsm, NULL);
-    CHECK(mid, FAIL, "H5Screate");
+    CHECK(mid, H5I_INVALID_HID, "H5Screate");
 
     /* Read all the selected 10th elements in the dataset into "rdata" */
     ret = H5Dread(did, H5T_NATIVE_INT, mid, sid, H5P_DEFAULT, rdata);