The patch titled
Subject: selftests/vm: anon_cow: THP tests
has been added to the -mm mm-unstable branch. Its filename is
selftests-vm-anon_cow-thp-tests.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-vm-anon_cow-thp-tests.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: David Hildenbrand <david@xxxxxxxxxx>
Subject: selftests/vm: anon_cow: THP tests
Date: Tue, 27 Sep 2022 13:01:16 +0200
Let's add various THP variants that we'll run with our existing test
cases.
Link: https://lkml.kernel.org/r/20220927110120.106906-4-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Christoph von Recklinghausen <crecklin@xxxxxxxxxx>
Cc: Don Dutile <ddutile@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Cc: Nadav Amit <namit@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/vm/anon_cow.c | 259 +++++++++++++++++++++++-
1 file changed, 258 insertions(+), 1 deletion(-)
--- a/tools/testing/selftests/vm/anon_cow.c~selftests-vm-anon_cow-thp-tests
+++ a/tools/testing/selftests/vm/anon_cow.c
@@ -24,6 +24,43 @@
static size_t pagesize;
static int pagemap_fd;
+static size_t thpsize;
+
+static void detect_thpsize(void)
+{
+ int fd = open("/sys/kernel/mm/transparent_hugepage/hpage_pmd_size",
+ O_RDONLY);
+ size_t size = 0;
+ char buf[15];
+ int ret;
+
+ if (fd < 0)
+ return;
+
+ ret = pread(fd, buf, sizeof(buf), 0);
+ if (ret > 0 && ret < sizeof(buf)) {
+ buf[ret] = 0;
+
+ size = strtoul(buf, NULL, 10);
+ if (size < pagesize)
+ size = 0;
+ if (size > 0) {
+ thpsize = size;
+ ksft_print_msg("[INFO] detected THP size: %zu KiB\n",
+ thpsize / 1024);
+ }
+ }
+
+ close(fd);
+}
+
+static bool range_is_swapped(void *addr, size_t size)
+{
+ for (; size; addr += pagesize, size -= pagesize)
+ if (!pagemap_is_swapped(pagemap_fd, addr))
+ return false;
+ return true;
+}
struct comm_pipes {
int child_ready[2];
@@ -319,6 +356,206 @@ static void run_with_base_page_swap(test
do_run_with_base_page(fn, true);
}
+enum thp_run {
+ THP_RUN_PMD,
+ THP_RUN_PMD_SWAPOUT,
+ THP_RUN_PTE,
+ THP_RUN_PTE_SWAPOUT,
+ THP_RUN_SINGLE_PTE,
+ THP_RUN_SINGLE_PTE_SWAPOUT,
+ THP_RUN_PARTIAL_MREMAP,
+ THP_RUN_PARTIAL_SHARED,
+};
+
+static void do_run_with_thp(test_fn fn, enum thp_run thp_run)
+{
+ char *mem, *mmap_mem, *tmp, *mremap_mem = MAP_FAILED;
+ size_t size, mmap_size, mremap_size;
+ int ret;
+
+ /* For alignment purposes, we need twice the thp size. */
+ mmap_size = 2 * thpsize;
+ mmap_mem = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ if (mmap_mem == MAP_FAILED) {
+ ksft_test_result_fail("mmap() failed\n");
+ return;
+ }
+
+ /* We need a THP-aligned memory area. */
+ mem = (char *)(((uintptr_t)mmap_mem + thpsize) & ~(thpsize - 1));
+
+ ret = madvise(mem, thpsize, MADV_HUGEPAGE);
+ if (ret) {
+ ksft_test_result_fail("MADV_HUGEPAGE failed\n");
+ goto munmap;
+ }
+
+ /*
+ * Try to populate a THP. Touch the first sub-page and test if we get
+ * another sub-page populated automatically.
+ */
+ mem[0] = 0;
+ if (!pagemap_is_populated(pagemap_fd, mem + pagesize)) {
+ ksft_test_result_skip("Did not get a THP populated\n");
+ goto munmap;
+ }
+ memset(mem, 0, thpsize);
+
+ size = thpsize;
+ switch (thp_run) {
+ case THP_RUN_PMD:
+ case THP_RUN_PMD_SWAPOUT:
+ break;
+ case THP_RUN_PTE:
+ case THP_RUN_PTE_SWAPOUT:
+ /*
+ * Trigger PTE-mapping the THP by temporarily mapping a single
+ * subpage R/O.
+ */
+ ret = mprotect(mem + pagesize, pagesize, PROT_READ);
+ if (ret) {
+ ksft_test_result_fail("mprotect() failed\n");
+ goto munmap;
+ }
+ ret = mprotect(mem + pagesize, pagesize, PROT_READ | PROT_WRITE);
+ if (ret) {
+ ksft_test_result_fail("mprotect() failed\n");
+ goto munmap;
+ }
+ break;
+ case THP_RUN_SINGLE_PTE:
+ case THP_RUN_SINGLE_PTE_SWAPOUT:
+ /*
+ * Discard all but a single subpage of that PTE-mapped THP. What
+ * remains is a single PTE mapping a single subpage.
+ */
+ ret = madvise(mem + pagesize, thpsize - pagesize, MADV_DONTNEED);
+ if (ret) {
+ ksft_test_result_fail("MADV_DONTNEED failed\n");
+ goto munmap;
+ }
+ size = pagesize;
+ break;
+ case THP_RUN_PARTIAL_MREMAP:
+ /*
+ * Remap half of the THP. We need some new memory location
+ * for that.
+ */
+ mremap_size = thpsize / 2;
+ mremap_mem = mmap(NULL, mremap_size, PROT_NONE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ if (mem == MAP_FAILED) {
+ ksft_test_result_fail("mmap() failed\n");
+ goto munmap;
+ }
+ tmp = mremap(mem + mremap_size, mremap_size, mremap_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, mremap_mem);
+ if (tmp != mremap_mem) {
+ ksft_test_result_fail("mremap() failed\n");
+ goto munmap;
+ }
+ size = mremap_size;
+ break;
+ case THP_RUN_PARTIAL_SHARED:
+ /*
+ * Share the first page of the THP with a child and quit the
+ * child. This will result in some parts of the THP never
+ * have been shared.
+ */
+ ret = madvise(mem + pagesize, thpsize - pagesize, MADV_DONTFORK);
+ if (ret) {
+ ksft_test_result_fail("MADV_DONTFORK failed\n");
+ goto munmap;
+ }
+ ret = fork();
+ if (ret < 0) {
+ ksft_test_result_fail("fork() failed\n");
+ goto munmap;
+ } else if (!ret) {
+ exit(0);
+ }
+ wait(&ret);
+ /* Allow for sharing all pages again. */
+ ret = madvise(mem + pagesize, thpsize - pagesize, MADV_DOFORK);
+ if (ret) {
+ ksft_test_result_fail("MADV_DOFORK failed\n");
+ goto munmap;
+ }
+ break;
+ default:
+ assert(false);
+ }
+
+ switch (thp_run) {
+ case THP_RUN_PMD_SWAPOUT:
+ case THP_RUN_PTE_SWAPOUT:
+ case THP_RUN_SINGLE_PTE_SWAPOUT:
+ madvise(mem, size, MADV_PAGEOUT);
+ if (!range_is_swapped(mem, size)) {
+ ksft_test_result_skip("MADV_PAGEOUT did not work, is swap enabled?\n");
+ goto munmap;
+ }
+ break;
+ default:
+ break;
+ }
+
+ fn(mem, size);
+munmap:
+ munmap(mmap_mem, mmap_size);
+ if (mremap_mem != MAP_FAILED)
+ munmap(mremap_mem, mremap_size);
+}
+
+static void run_with_thp(test_fn fn, const char *desc)
+{
+ ksft_print_msg("[RUN] %s ... with THP\n", desc);
+ do_run_with_thp(fn, THP_RUN_PMD);
+}
+
+static void run_with_thp_swap(test_fn fn, const char *desc)
+{
+ ksft_print_msg("[RUN] %s ... with swapped-out THP\n", desc);
+ do_run_with_thp(fn, THP_RUN_PMD_SWAPOUT);
+}
+
+static void run_with_pte_mapped_thp(test_fn fn, const char *desc)
+{
+ ksft_print_msg("[RUN] %s ... with PTE-mapped THP\n", desc);
+ do_run_with_thp(fn, THP_RUN_PTE);
+}
+
+static void run_with_pte_mapped_thp_swap(test_fn fn, const char *desc)
+{
+ ksft_print_msg("[RUN] %s ... with swapped-out, PTE-mapped THP\n", desc);
+ do_run_with_thp(fn, THP_RUN_PTE_SWAPOUT);
+}
+
+static void run_with_single_pte_of_thp(test_fn fn, const char *desc)
+{
+ ksft_print_msg("[RUN] %s ... with single PTE of THP\n", desc);
+ do_run_with_thp(fn, THP_RUN_SINGLE_PTE);
+}
+
+static void run_with_single_pte_of_thp_swap(test_fn fn, const char *desc)
+{
+ ksft_print_msg("[RUN] %s ... with single PTE of swapped-out THP\n", desc);
+ do_run_with_thp(fn, THP_RUN_SINGLE_PTE_SWAPOUT);
+}
+
+static void run_with_partial_mremap_thp(test_fn fn, const char *desc)
+{
+ ksft_print_msg("[RUN] %s ... with partially mremap()'ed THP\n", desc);
+ do_run_with_thp(fn, THP_RUN_PARTIAL_MREMAP);
+}
+
+static void run_with_partial_shared_thp(test_fn fn, const char *desc)
+{
+ ksft_print_msg("[RUN] %s ... with partially shared THP\n", desc);
+ do_run_with_thp(fn, THP_RUN_PARTIAL_SHARED);
+}
+
struct test_case {
const char *desc;
test_fn fn;
@@ -367,6 +604,16 @@ static void run_test_case(struct test_ca
{
run_with_base_page(test_case->fn, test_case->desc);
run_with_base_page_swap(test_case->fn, test_case->desc);
+ if (thpsize) {
+ run_with_thp(test_case->fn, test_case->desc);
+ run_with_thp_swap(test_case->fn, test_case->desc);
+ run_with_pte_mapped_thp(test_case->fn, test_case->desc);
+ run_with_pte_mapped_thp_swap(test_case->fn, test_case->desc);
+ run_with_single_pte_of_thp(test_case->fn, test_case->desc);
+ run_with_single_pte_of_thp_swap(test_case->fn, test_case->desc);
+ run_with_partial_mremap_thp(test_case->fn, test_case->desc);
+ run_with_partial_shared_thp(test_case->fn, test_case->desc);
+ }
}
static void run_test_cases(void)
@@ -377,15 +624,25 @@ static void run_test_cases(void)
run_test_case(&test_cases[i]);
}
+static int tests_per_test_case(void)
+{
+ int tests = 2;
+
+ if (thpsize)
+ tests += 8;
+ return tests;
+}
+
int main(int argc, char **argv)
{
int nr_test_cases = ARRAY_SIZE(test_cases);
int err;
pagesize = getpagesize();
+ detect_thpsize();
ksft_print_header();
- ksft_set_plan(nr_test_cases * 2);
+ ksft_set_plan(nr_test_cases * tests_per_test_case());
pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
if (pagemap_fd < 0)
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
selftests-vm-add-test-to-measure-madv_unmergeable-performance.patch
mm-ksm-simplify-break_ksm-to-not-rely-on-vm_fault_write.patch
mm-remove-vm_fault_write.patch
mm-ksm-fix-ksm-cow-breaking-with-userfaultfd-wp-via-fault_flag_unshare.patch
mm-pagewalk-add-walk_page_range_vma.patch
mm-ksm-convert-break_ksm-to-use-walk_page_range_vma.patch
mm-gup-remove-foll_migration.patch
selftests-vm-anon_cow-test-cow-handling-of-anonymous-memory.patch
selftests-vm-factor-out-pagemap_is_populated-into-vm_util.patch
selftests-vm-anon_cow-thp-tests.patch
selftests-vm-anon_cow-hugetlb-tests.patch
selftests-vm-anon_cow-add-liburing-test-cases.patch
mm-gup_test-start-stop-read-functionality-for-pin-longterm-test.patch
selftests-vm-anon_cow-add-r-o-longterm-tests-via-gup_test.patch
