The patch titled
Subject: selftests/mm: add tests for folio_split(), buddy allocator like split.
has been added to the -mm mm-unstable branch. Its filename is
selftests-mm-add-tests-for-folio_split-buddy-allocator-like-split.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-add-tests-for-folio_split-buddy-allocator-like-split.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Zi Yan <ziy@xxxxxxxxxx>
Subject: selftests/mm: add tests for folio_split(), buddy allocator like split.
Date: Tue, 4 Feb 2025 22:14:17 -0500
It splits page cache folios to orders from 0 to 8 at different in-folio
offsets.
Link: https://lkml.kernel.org/r/20250205031417.1771278-8-ziy@xxxxxxxxxx
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Hugh Dickens <hughd@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Kirill A. Shuemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: linmiaohe <linmiaohe@xxxxxxxxxx>
Cc: Mattew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Yang Shi <yang@xxxxxxxxxxxxxxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/mm/split_huge_page_test.c | 34 +++++++++---
1 file changed, 27 insertions(+), 7 deletions(-)
--- a/tools/testing/selftests/mm/split_huge_page_test.c~selftests-mm-add-tests-for-folio_split-buddy-allocator-like-split
+++ a/tools/testing/selftests/mm/split_huge_page_test.c
@@ -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 @@ err_out_unlink:
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(siz
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 @@ out:
munmap(addr, fd_size);
close(fd);
unlink(testfile);
- 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);
+ 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();
_
Patches currently in -mm which might be from ziy@xxxxxxxxxx are
selftests-mm-make-file-backed-thp-split-work-by-writing-pmd-size-data.patch
mm-huge_memory-allow-split-shmem-large-folio-to-any-lower-order.patch
selftests-mm-test-splitting-file-backed-thp-to-any-lower-order.patch
mm-huge_memory-add-two-new-not-yet-used-functions-for-folio_split.patch
mm-huge_memory-move-folio-split-common-code-to-__folio_split.patch
mm-huge_memory-add-buddy-allocator-like-folio_split.patch
mm-huge_memory-remove-the-old-unused-__split_huge_page.patch
mm-huge_memory-add-folio_split-to-debugfs-testing-interface.patch
mm-truncate-use-buddy-allocator-like-folio-split-for-truncate-operation.patch
selftests-mm-add-tests-for-folio_split-buddy-allocator-like-split.patch
