Commit 80a5c494 authored by Zi Yan's avatar Zi Yan Committed by Andrew Morton
Browse files

selftests/mm: add tests for folio_split(), buddy allocator like split 

It splits page cache folios to orders from 0 to 8 at different in-folio
offset.

Link: https://lkml.kernel.org/r/20250307174001.242794-9-ziy@nvidia.com


Signed-off-by: default avatarZi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Kairui Song <kasong@tencent.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 7460b470

tools/testing/selftests/mm/split_huge_page_test.c

+27 −7
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <fcntl.h>

#include <sys/mman.h>

#include <sys/mount.h>

#include <sys/param.h>

#include <malloc.h>

#include <stdbool.h>

#include <time.h>
@@ -456,7 +457,8 @@ int create_pagecache_thp_and_fd(const char *testfile, size_t fd_size, int *fd, 
	return -1;

}



void split_thp_in_pagecache_to_order(size_t fd_size, int order, const char *fs_loc)

void split_thp_in_pagecache_to_order_at(size_t fd_size, const char *fs_loc,

		int order, int offset)

{

	int fd;

	char *addr;
@@ -474,7 +476,12 @@ void split_thp_in_pagecache_to_order(size_t fd_size, int order, const char *fs_l 
		return;

	err = 0;



	write_debugfs(PID_FMT, getpid(), (uint64_t)addr, (uint64_t)addr + fd_size, order);

	if (offset == -1)

		write_debugfs(PID_FMT, getpid(), (uint64_t)addr,

			      (uint64_t)addr + fd_size, order);

	else

		write_debugfs(PID_FMT, getpid(), (uint64_t)addr,

			      (uint64_t)addr + fd_size, order, offset);



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

		if (*(addr + i) != (char)i) {
@@ -493,9 +500,15 @@ void split_thp_in_pagecache_to_order(size_t fd_size, int order, const char *fs_l 
	munmap(addr, fd_size);

	close(fd);

	unlink(testfile);

	if (offset == -1) {

		if (err)

			ksft_exit_fail_msg("Split PMD-mapped pagecache folio to order %d failed\n", order);

		ksft_test_result_pass("Split PMD-mapped pagecache folio to order %d passed\n", order);

	} else {

		if (err)

			ksft_exit_fail_msg("Split PMD-mapped pagecache folio to order %d at in-folio offset %d failed\n", order, offset);

		ksft_test_result_pass("Split PMD-mapped pagecache folio to order %d at in-folio offset %d passed\n", order, offset);

	}

}



int main(int argc, char **argv)
@@ -506,6 +519,7 @@ int main(int argc, char **argv) 
	char fs_loc_template[] = "/tmp/thp_fs_XXXXXX";

	const char *fs_loc;

	bool created_tmp;

	int offset;



	ksft_print_header();
@@ -517,7 +531,7 @@ int main(int argc, char **argv) 
	if (argc > 1)

		optional_xfs_path = argv[1];



	ksft_set_plan(1+8+1+9+9);

	ksft_set_plan(1+8+1+9+9+8*4+2);



	pagesize = getpagesize();

	pageshift = ffs(pagesize) - 1;
@@ -540,7 +554,13 @@ int main(int argc, char **argv) 
	created_tmp = prepare_thp_fs(optional_xfs_path, fs_loc_template,

			&fs_loc);

	for (i = 8; i >= 0; i--)

		split_thp_in_pagecache_to_order(fd_size, i, fs_loc);

		split_thp_in_pagecache_to_order_at(fd_size, fs_loc, i, -1);



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

		for (offset = 0;

		     offset < pmd_pagesize / pagesize;

		     offset += MAX(pmd_pagesize / pagesize / 4, 1 << i))

			split_thp_in_pagecache_to_order_at(fd_size, fs_loc, i, offset);

	cleanup_thp_fs(fs_loc, created_tmp);



	ksft_finished();