Commit dfe61db4 authored by Zi Yan's avatar Zi Yan Committed by Andrew Morton
Browse files

selftests/mm: add tests for splitting pmd THPs to all lower orders 

Kernel already supports splitting a folio to any lower order. Test it.

[ziy@nvidia.com: no need to test splitting to order-1]
 Link: https://lkml.kernel.org/r/DDA202EA-4664-4F50-A7FD-B00CBB7A624B@nvidia.com
Link: https://lkml.kernel.org/r/20250110235028.96824-2-ziy@nvidia.com


Signed-off-by: default avatarZi Yan <ziy@nvidia.com>
Cc: Alexander Zhu <alexlzhu@fb.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 136c5b40

tools/testing/selftests/mm/split_huge_page_test.c

+9 −5
Original line number Diff line number Diff line
@@ -144,7 +144,7 @@ void split_pmd_zero_pages(void) 
	free(one_page);

}



void split_pmd_thp(void)

void split_pmd_thp_to_order(int order)

{

	char *one_page;

	size_t len = 4 * pmd_pagesize;
@@ -164,7 +164,7 @@ void split_pmd_thp(void) 


	/* split all THPs */

	write_debugfs(PID_FMT, getpid(), (uint64_t)one_page,

		(uint64_t)one_page + len, 0);

		(uint64_t)one_page + len, order);



	for (i = 0; i < len; i++)

		if (one_page[i] != (char)i)
@@ -174,7 +174,7 @@ void split_pmd_thp(void) 
	if (!check_huge_anon(one_page, 0, pmd_pagesize))

		ksft_exit_fail_msg("Still AnonHugePages not split\n");



	ksft_test_result_pass("Split huge pages successful\n");

	ksft_test_result_pass("Split huge pages to order %d successful\n", order);

	free(one_page);

}
@@ -481,7 +481,7 @@ int main(int argc, char **argv) 
	if (argc > 1)

		optional_xfs_path = argv[1];



	ksft_set_plan(4+9);

	ksft_set_plan(1+8+2+9);



	pagesize = getpagesize();

	pageshift = ffs(pagesize) - 1;
@@ -492,7 +492,11 @@ int main(int argc, char **argv) 
	fd_size = 2 * pmd_pagesize;



	split_pmd_zero_pages();

	split_pmd_thp();



	for (i = 0; i < 9; i++)

		if (i != 1)

			split_pmd_thp_to_order(i);



	split_pte_mapped_thp();

	split_file_backed_thp();