diff -up hdf5-1.10.4/testpar/t_cache.c.warning hdf5-1.10.4/testpar/t_cache.c
--- hdf5-1.10.4/testpar/t_cache.c.warning	2018-09-10 08:43:41.000000000 -0600
+++ hdf5-1.10.4/testpar/t_cache.c	2018-11-24 08:08:37.333832898 -0700
@@ -79,8 +79,8 @@ long local_pins           = 0;
 
 
 /* the following fields are used by the server process only */
-int total_reads           = 0;
-int total_writes           = 0;
+unsigned total_reads           = 0;
+unsigned total_writes           = 0;
 
 
 /*****************************************************************************
@@ -175,8 +175,8 @@ struct datum
     hbool_t        local_pinned;
     hbool_t        cleared;
     hbool_t             flushed;
-    int            reads;
-    int            writes;
+    unsigned       reads;
+    unsigned       writes;
     int            index;
     struct H5AC_aux_t * aux_ptr;
 };
@@ -2197,7 +2197,7 @@ serve_entry_reads_request(struct mssg_t
             reply.base_addr = target_addr;
             reply.len       = 0;
             reply.ver       = 0;
-        reply.count     = (long)(data[target_index].reads);
+            reply.count     = data[target_index].reads;
             reply.magic     = MSSG_MAGIC;
         }
     }
@@ -2446,12 +2446,12 @@ static herr_t
 datum_image_len(const void *thing, size_t *image_len)
 {
     int idx;
-    struct datum * entry_ptr;
+    const struct datum * entry_ptr;
 
     HDassert( thing );
     HDassert( image_len );
 
-    entry_ptr = (struct datum *)thing;
+    entry_ptr = (const struct datum *)thing;
 
     idx = addr_to_datum_index(entry_ptr->base_addr);
 
@@ -4615,7 +4615,7 @@ verify_entry_reads(haddr_t addr,
                    int expected_entry_reads)
 {
     hbool_t success = TRUE;
-    int reported_entry_reads;
+    unsigned reported_entry_reads = 0;
     struct mssg_t mssg;
 
     if ( success ) {
@@ -4722,7 +4722,7 @@ verify_entry_writes(haddr_t addr,
                     int expected_entry_writes)
 {
     hbool_t success = TRUE;
-    int reported_entry_writes;
+    unsigned reported_entry_writes = 0;
     struct mssg_t mssg;
 
     if ( success ) {
@@ -4827,7 +4827,7 @@ static hbool_t
 verify_total_reads(int expected_total_reads)
 {
     hbool_t success = TRUE; /* will set to FALSE if appropriate. */
-    long reported_total_reads;
+    unsigned reported_total_reads;
     struct mssg_t mssg;
 
     if ( success ) {