Add tests similar to the existing THP tests, but which operate on memory
backed by smaller-order, PTE-mapped THP. This reuses all the existing
infrastructure. If the test suite detects that small-order THP is not
supported by the kernel, the new tests are skipped.
Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx>
---
tools/testing/selftests/mm/cow.c | 93 ++++++++++++++++++++++++++++++++
1 file changed, 93 insertions(+)
diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
index d887ce454e34..6c5e37d8bb69 100644
--- a/tools/testing/selftests/mm/cow.c
+++ b/tools/testing/selftests/mm/cow.c
@@ -33,10 +33,13 @@
static size_t pagesize;
static int pagemap_fd;
static size_t pmdsize;
+static size_t ptesize;
static int nr_hugetlbsizes;
static size_t hugetlbsizes[10];
static int gup_fd;
static bool has_huge_zeropage;
+static unsigned int orig_anon_orders;
+static bool orig_anon_orders_valid;
static void detect_huge_zeropage(void)
{
@@ -1118,6 +1121,14 @@ static void run_anon_test_case(struct test_case const *test_case)
run_with_partial_mremap_thp(test_case->fn, test_case->desc, pmdsize);
run_with_partial_shared_thp(test_case->fn, test_case->desc, pmdsize);
}
+ if (ptesize) {
+ run_with_pte_mapped_thp(test_case->fn, test_case->desc, ptesize);
+ run_with_pte_mapped_thp_swap(test_case->fn, test_case->desc, ptesize);
+ run_with_single_pte_of_thp(test_case->fn, test_case->desc, ptesize);
+ run_with_single_pte_of_thp_swap(test_case->fn, test_case->desc, ptesize);
+ run_with_partial_mremap_thp(test_case->fn, test_case->desc, ptesize);
+ run_with_partial_shared_thp(test_case->fn, test_case->desc, ptesize);
+ }
for (i = 0; i < nr_hugetlbsizes; i++)
run_with_hugetlb(test_case->fn, test_case->desc,
hugetlbsizes[i]);
@@ -1139,6 +1150,8 @@ static int tests_per_anon_test_case(void)
if (pmdsize)
tests += 8;
+ if (ptesize)
+ tests += 6;
return tests;
}
@@ -1693,6 +1706,80 @@ static int tests_per_non_anon_test_case(void)
return tests;
}
+#define ANON_ORDERS_FILE "/sys/kernel/mm/transparent_hugepage/anon_orders"
+
+static int read_anon_orders(unsigned int *orders)
+{
+ ssize_t buflen = 80;
+ char buf[buflen];
+ int fd;
+
+ fd = open(ANON_ORDERS_FILE, O_RDONLY);
+ if (fd == -1)
+ return -1;
+
+ buflen = read(fd, buf, buflen);
+ close(fd);
+
+ if (buflen < 1)
+ return -1;
+
+ *orders = strtoul(buf, NULL, 16);
+
+ return 0;
+}
+
+static int write_anon_orders(unsigned int orders)
+{
+ ssize_t buflen = 80;
+ char buf[buflen];
+ int fd;
+
+ fd = open(ANON_ORDERS_FILE, O_WRONLY);
+ if (fd == -1)
+ return -1;
+
+ buflen = snprintf(buf, buflen, "0x%08x\n", orders);
+ buflen = write(fd, buf, buflen);
+ close(fd);
+
+ if (buflen < 1)
+ return -1;
+
+ return 0;
+}
+
+static size_t save_thp_anon_orders(void)
+{
+ /*
+ * If the kernel supports multiple orders for anon THP (indicated by the
+ * presence of anon_orders file), configure it for the PMD-order and the
+ * PMD-order - 1, which we will report back and use as the PTE-order THP
+ * size. Save the original value so that it can be restored on exit. If
+ * the kernel does not support multiple orders, report back 0 for the
+ * PTE-size so those tests are skipped.
+ */
+
+ int pteorder = sz2ord(pmdsize) - 1;
+ unsigned int orders = (1UL << sz2ord(pmdsize)) | (1UL << pteorder);
+
+ if (read_anon_orders(&orig_anon_orders))
+ return 0;
+
+ orig_anon_orders_valid = true;
+
+ if (write_anon_orders(orders))
+ return 0;
+
+ return pagesize << pteorder;
+}
+
+static void restore_thp_anon_orders(void)
+{
+ if (orig_anon_orders_valid)
+ write_anon_orders(orig_anon_orders);
+}
+
int main(int argc, char **argv)
{
int err;
@@ -1702,6 +1789,10 @@ int main(int argc, char **argv)
if (pmdsize)
ksft_print_msg("[INFO] detected PMD-mapped THP size: %zu KiB\n",
pmdsize / 1024);
+ ptesize = save_thp_anon_orders();
+ if (ptesize)
+ ksft_print_msg("[INFO] configured PTE-mapped THP size: %zu KiB\n",
+ ptesize / 1024);
nr_hugetlbsizes = detect_hugetlb_page_sizes(hugetlbsizes,
ARRAY_SIZE(hugetlbsizes));
detect_huge_zeropage();
@@ -1720,6 +1811,8 @@ int main(int argc, char **argv)
run_anon_thp_test_cases();
run_non_anon_test_cases();
+ restore_thp_anon_orders();
+
err = ksft_get_fail_cnt();
if (err)
ksft_exit_fail_msg("%d out of %d tests failed\n",
--
2.25.1
