Re: [PATCH v3 39/54] selftests/mm: hugetlb-mmap: add setup of HugeTLB pages

[Sarthak Sharma]

On 4/29/26 2:12 AM, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>
> 
> hugetlb-mmap test fails if there are no free huge pages prepared by a
> wrapper script.
> 
> Add setup of HugeTLB pages to the test and make sure that the original
> settings are restored on the test exit.
> 
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>

I have run the test before and after applying the patch. Before the
patch, the test bailed out with mmap error if hugepages were not
preallocated. After the patch, the test correctly allocates the required
hugepages and successfully passes.

Tested-by: Sarthak Sharma <sarthak.sharma@xxxxxxx>

> ---
>  tools/testing/selftests/mm/hugetlb-mmap.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/testing/selftests/mm/hugetlb-mmap.c b/tools/testing/selftests/mm/hugetlb-mmap.c
> index 031085cb7d17..f12fc288ef4f 100644
> --- a/tools/testing/selftests/mm/hugetlb-mmap.c
> +++ b/tools/testing/selftests/mm/hugetlb-mmap.c
> @@ -109,16 +109,16 @@ int main(int argc, char **argv)
>  {
>  	size_t hugepage_size;
>  	size_t length = LENGTH;
> -	int shift = 0;
> +	int shift = 0, nr;
>  
>  	ksft_print_header();
> -	ksft_set_plan(2);
>  
>  	if (argc > 1)
>  		length = atol(argv[1]) << 20;
>  	if (argc > 2)
>  		shift = atoi(argv[2]);
>  
> +	hugetlb_save_settings();
>  	if (shift) {
>  		hugepage_size = (1 << shift);
>  		ksft_print_msg("%u kB hugepages\n", 1 << (shift - 10));
> @@ -128,9 +128,14 @@ int main(int argc, char **argv)
>  	}
>  
>  	/* munmap with fail if the length is not page aligned */
> -	if (hugepage_size > length)
> -		length = hugepage_size;
> +	length = (length + hugepage_size - 1) & ~(hugepage_size - 1);
> +	nr = length / hugepage_size;
> +
> +	hugetlb_set_nr_pages(hugepage_size, nr);
> +	if (hugetlb_free_pages(hugepage_size) < nr)
> +		ksft_exit_skip("Not enough %lu Kb pages\n", hugepage_size >> 10);
>  
> +	ksft_set_plan(2);
>  	ksft_print_msg("Mapping %lu Mbytes\n", (unsigned long)length >> 20);
>  
>  	test_anon_mmap(length, shift);