[LTP] [PATCH v2 31/31] testcases: sysfs: Add sys_thp01

[Cyril Hrubis]

A test for /sys/kernel/mm/transparent_hugepage/* files.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
---
 runtest/sysfs                                 |  1 +
 .../kernel/mm/transparent_hugepage/.gitignore |  1 +
 .../kernel/mm/transparent_hugepage/Makefile   |  7 ++
 .../mm/transparent_hugepage/sys_thp01.c       | 86 +++++++++++++++++++
 4 files changed, 95 insertions(+)
 create mode 100644 testcases/kernel/sysfs/kernel/mm/transparent_hugepage/.gitignore
 create mode 100644 testcases/kernel/sysfs/kernel/mm/transparent_hugepage/Makefile
 create mode 100644 testcases/kernel/sysfs/kernel/mm/transparent_hugepage/sys_thp01.c

diff --git a/runtest/sysfs b/runtest/sysfs
index 7d59ae701..5eb8f81f8 100644
--- a/runtest/sysfs
+++ b/runtest/sysfs
@@ -26,3 +26,4 @@ sys_hugepages01 sys_hugepages01
 sys_hugepages02 sys_hugepages02
 sys_ksm01 sys_ksm01
 sys_mm_swap01 sys_mm_swap01
+sys_thp01 sys_thp01
diff --git a/testcases/kernel/sysfs/kernel/mm/transparent_hugepage/.gitignore b/testcases/kernel/sysfs/kernel/mm/transparent_hugepage/.gitignore
new file mode 100644
index 000000000..bdb564dfe
--- /dev/null
+++ b/testcases/kernel/sysfs/kernel/mm/transparent_hugepage/.gitignore
@@ -0,0 +1 @@
+/sys_thp01
diff --git a/testcases/kernel/sysfs/kernel/mm/transparent_hugepage/Makefile b/testcases/kernel/sysfs/kernel/mm/transparent_hugepage/Makefile
new file mode 100644
index 000000000..781865569
--- /dev/null
+++ b/testcases/kernel/sysfs/kernel/mm/transparent_hugepage/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2026 Cyril Hrubis <chrubis@suse.cz>
+
+top_srcdir		?= ../../../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/kernel/sysfs/kernel/mm/transparent_hugepage/sys_thp01.c b/testcases/kernel/sysfs/kernel/mm/transparent_hugepage/sys_thp01.c
new file mode 100644
index 000000000..88200afa0
--- /dev/null
+++ b/testcases/kernel/sysfs/kernel/mm/transparent_hugepage/sys_thp01.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2026 Cyril Hrubis <chrubis@suse.cz>
+ */
+
+/*\
+ * Sanity checks for the Transparent HugePage (THP) attributes exported under
+ * /sys/kernel/mm/transparent_hugepage/.
+ *
+ * The test verifies that:
+ *
+ * - enabled is a bracketed-choice file selecting one of always/madvise/never
+ * - defrag selects one of always/defer/defer+madvise/madvise/never
+ * - shmem_enabled selects one of always/within_size/advise/never/deny/force
+ * - use_zero_page is a boolean
+ * - hpage_pmd_size is a power of two and larger than the base page size
+ *
+ * All checks skip gracefully with TCONF when a particular attribute is not
+ * present, since the set of THP tunables differs between kernel versions.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include "tst_test.h"
+#include "tst_sysfs_assert.h"
+
+#define THP "/sys/kernel/mm/transparent_hugepage"
+
+static const char *const enabled_allowed[] = {
+	"always", "madvise", "never", NULL
+};
+
+static const char *const defrag_allowed[] = {
+	"always", "defer", "defer+madvise", "madvise", "never", NULL
+};
+
+static const char *const shmem_allowed[] = {
+	"always", "within_size", "advise", "never", "deny", "force", NULL
+};
+
+static void check_hpage_pmd_size(void)
+{
+	long size, pagesize;
+
+	if (access(THP "/hpage_pmd_size", F_OK)) {
+		tst_res(TCONF, THP "/hpage_pmd_size does not exist");
+		return;
+	}
+
+	TST_SYSFS_ASSERT_POW2(THP "/hpage_pmd_size");
+
+	size = TST_SYSFS_READ_LI(THP "/hpage_pmd_size");
+	pagesize = getpagesize();
+
+	if (size > pagesize) {
+		tst_res(TPASS, "hpage_pmd_size (%ld) > page size (%ld)",
+			size, pagesize);
+	} else {
+		tst_res(TFAIL, "hpage_pmd_size (%ld) <= page size (%ld)",
+			size, pagesize);
+	}
+}
+
+static void run(void)
+{
+	char sel[32];
+
+	TST_SYSFS_ASSERT_CHOICE(enabled_allowed, sel, sizeof(sel),
+				THP "/enabled");
+	TST_SYSFS_ASSERT_CHOICE(defrag_allowed, sel, sizeof(sel),
+				THP "/defrag");
+	TST_SYSFS_ASSERT_CHOICE(shmem_allowed, sel, sizeof(sel),
+				THP "/shmem_enabled");
+
+	TST_SYSFS_ASSERT_BOOL(THP "/use_zero_page");
+
+	check_hpage_pmd_size();
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	.needs_kconfigs = (const char *const[]){
+		"CONFIG_TRANSPARENT_HUGEPAGE=y",
+		NULL
+	},
+};
-- 
2.54.0