[LTP] hugemmap24 failure on aarch64 with 512MB hugepages

[Li Wang]

[Cc'ing Jan Stancek]

On Wed, Mar 8, 2023 at 5:51 PM Cyril Hrubis <chrubis@suse.cz> wrote:

> Hi!
> Looks like the hugemmap24 test fails on aarch64 with 512MB hugepages
> since it attempts to MAP_FIXED at NULL address, any idea why aarch64 is
> limited to 0x10000000 as slice boundary?
>

It looks like a generic/random slice_boundary that tries as a
basic gap between two available free neighbor slices.

https://github.com/libhugetlbfs/libhugetlbfs/commit/8ee2462f3f6eea72067641a197214610443576b8
https://github.com/libhugetlbfs/libhugetlbfs/commit/399cda578564bcd52553ab88827a82481b4034d1

I guess it doesn't matter just to increase the size of the boundary.
or, we can skip testing on a big page-size system like aarch64(with 512MB)
if unable to find the free slices.

Test passed from my side with patch:

--- a/testcases/kernel/mem/hugetlb/hugemmap/hugemmap24.c
+++ b/testcases/kernel/mem/hugetlb/hugemmap/hugemmap24.c
@@ -37,7 +37,7 @@ static int init_slice_boundary(int fd)
 #else
        /* powerpc: 256MB slices up to 4GB */
        slice_boundary = 0x00000000;
-       slice_size = 0x10000000;
+       slice_size = 0x100000000;
 #endif

        /* dummy malloc so we know where is heap */



>
> See: https://github.com/linux-test-project/ltp/issues/1022
>
> --
> Cyril Hrubis
> chrubis@suse.cz
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>
>

-- 
Regards,
Li Wang