commit f008e0d18a4ba8ac26b67c5989efde3406bce535
Author: Jan Stancek <jstancek@redhat.com>
Date:   Fri Dec 5 13:57:04 2014 +0100

    lower mmap size of map_high_truncate_2 on 32bit s390
    
    The low and high limit passed to vm_unmapped_area() in
    hugetlb_get_unmapped_area() is (TASK_UNMAPPED_BASE, TASK_SIZE).
    
    On 64-bit kernel this is defined as:
      #define TASK_UNMAPPED_BASE (test_thread_flag(TIF_31BIT) ? \
                                 (1UL << 30) : (1UL << 41))
      #define TASK_SIZE_OF(tsk)  ((tsk)->mm->context.asce_limit)
    
    For 32-bit (-m31) process, this can be as small as
    (0x40000000, 0x80000000), which is 0x40000000 bytes long area.
    This testcase however is trying to allocate 0x60000000 and fails:
      FAIL mmap() 1: Cannot allocate memory
    
    Lower mmap size to ~0x20000000, which is more likely to suit
    address space constraints of 32-bit s390.
    
    Signed-off-by: Jan Stancek <jstancek@redhat.com>
    Signed-off-by: Eric B Munson <emunson@mgebm.net>

diff --git a/tests/map_high_truncate_2.c b/tests/map_high_truncate_2.c
index daabd00..2a2560b 100644
--- a/tests/map_high_truncate_2.c
+++ b/tests/map_high_truncate_2.c
@@ -50,7 +50,11 @@
  * 856fc29505556cf263f3dcda2533cf3766c14ab6.
  */
 #define MAP_LENGTH	(4 * hpage_size)
-#define TRUNCATE_POINT	0x60000000UL
+#if defined(__s390__) && __WORDSIZE == 32
+#define TRUNCATE_POINT 0x20000000UL
+#else
+#define TRUNCATE_POINT 0x60000000UL
+#endif
 #define HIGH_ADDR	0xa0000000UL
 
 int main(int argc, char *argv[])