On Mon, Nov 14, 2016 at 02:44:29PM -0800, Andrew Morton wrote:
> On Mon, 14 Nov 2016 15:07:33 +0800 Huang Shijie <shijie.huang@arm.com> wrote:
> I'm not really seeing a description of the actual bug.  I don't know
> what counter.sh is, there is no copy of counter.sh included in the
> changelogs and there is no description of the kernel error which
> counter.sh demonstrates.
> 
> So can you pleaser send to me a copy of counter.sh as well as a
> suitable description of the kernel error which counter.sh triggers?
> 
Sorry.

The counter.sh is just a wrapper for counter.c.
I append them in the attachment, you can also find them in:
  https://github.com/libhugetlbfs/libhugetlbfs/blob/master/tests/counters.c
  https://github.com/libhugetlbfs/libhugetlbfs/blob/master/tests/counters.sh

The description:
 The "counter.sh" test case will fail when we test the ARM64 32M gigantic page.
 The error shows below:

 ----------------------------------------------------------
        ...........................................
	LD_PRELOAD=libhugetlbfs.so shmoverride_unlinked (32M: 64):	PASS
	LD_PRELOAD=libhugetlbfs.so HUGETLB_SHM=yes shmoverride_unlinked (32M: 64):	PASS
	quota.sh (32M: 64):	PASS
	counters.sh (32M: 64):	FAIL mmap failed: Invalid argument
	********** TEST SUMMARY
	*                      32M           
	*                      32-bit 64-bit 
	*     Total testcases:     0     87   
	*             Skipped:     0      0   
	*                PASS:     0     86   
	*                FAIL:     0      1   
	*    Killed by signal:     0      0   
	*   Bad configuration:     0      0   
	*       Expected FAIL:     0      0   
	*     Unexpected PASS:     0      0   
	* Strange test result:     0      0   
	**********
 ----------------------------------------------------------

The failure is caused by:
 1) kernel fails to allocate a gigantic page for the surplus case.
    And the gather_surplus_pages() will return NULL in the end.

 2) The condition checks for some functions are wrong:
     return_unused_surplus_pages()
     nr_overcommit_hugepages_store()
     hugetlb_overcommit_handler()

  
Thanks
Huang Shijie