Add new tests to check the correctness of the `-overcommit memlock`
option (possible values: off, on, on-fault) by using
`/proc/{qemu_pid}/smaps` file to check in Size, Rss and Locked fields of
anonymous segments:
* if `memlock=off`, then Locked = 0 on every anonymous smaps;
* if `memlock=on`, then Size, Rss and Locked values must be equal for
every anon smaps where Rss is not 0;
* if `memlock=on-fault`, then Rss and Locked must be equal on every anon
smaps and anonymous segment with Rss < Size must exists.
Signed-off-by: Alexandr Moshkov <dtalexund...@yandex-team.ru>
---
tests/functional/meson.build | 1 +
tests/functional/test_memlock.py | 102 +++++++++++++++++++++++++++++++
2 files changed, 103 insertions(+)
create mode 100755 tests/functional/test_memlock.py
diff --git a/tests/functional/meson.build b/tests/functional/meson.build
index 0f8be30fe2..339af7835f 100644
--- a/tests/functional/meson.build
+++ b/tests/functional/meson.build
@@ -61,6 +61,7 @@ tests_generic_system = [
'empty_cpu_model',
'info_usernet',
'version',
+ 'memlock',
]
tests_generic_linuxuser = [
diff --git a/tests/functional/test_memlock.py b/tests/functional/test_memlock.py
new file mode 100755
index 0000000000..b62f12a715
--- /dev/null
+++ b/tests/functional/test_memlock.py
@@ -0,0 +1,102 @@
+# Functional test that check overcommit memlock options
+#
+# Copyright (c) Yandex Technologies LLC, 2025
+#
+# Author:
+# Alexandr Moshkov <dtalexund...@yandex-team.ru>
+#
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or
+# later. See the COPYING file in the top-level directory.
+
+import re
+
+from typing import List, Dict
+
+from qemu_test import QemuSystemTest
+from qemu_test import skipLockedMemoryTest
+
+
+SMAPS_HEADER_PATTERN = re.compile(r'^\w+-\w+', re.MULTILINE)
+SMAPS_VALUE_PATTERN = re.compile(r'^(\w+):\s+(\d+) kB', re.MULTILINE)
+
+
+@skipLockedMemoryTest(2_097_152) # 2GB
+class MemlockTest(QemuSystemTest):
+ """
+ Boots a Linux system with memlock options.
+ Then verify, that this options is working correctly
+ by checking the smaps of the QEMU proccess.
+ """
+
+ def common_vm_setup_with_memlock(self, memlock):
+ self.vm.add_args('-overcommit', f'mem-lock={memlock}')
+ self.vm.launch()
+
+ def get_anon_smaps_by_pid(self, pid):
+ smaps_raw = self._get_raw_smaps_by_pid(pid)
+ return self._parse_anonymous_smaps(smaps_raw)
+
+ def test_memlock_off(self):
+ self.common_vm_setup_with_memlock('off')
+
+ anon_smaps = self.get_anon_smaps_by_pid(self.vm.get_pid())
+
+ # locked = 0 on every smap
+ for smap in anon_smaps:
+ self.assertEqual(smap['Locked'], 0)
+
+ def test_memlock_on(self):
+ self.common_vm_setup_with_memlock('on')
+
+ anon_smaps = self.get_anon_smaps_by_pid(self.vm.get_pid())
+
+ # size = rss = locked on every smap where rss not 0
+ for smap in anon_smaps:
+ if smap['Rss'] == 0:
+ continue
+ self.assertTrue(smap['Size'] == smap['Rss'] == smap['Locked'])
+
+ def test_memlock_onfault(self):
+ self.common_vm_setup_with_memlock('on-fault')
+
+ anon_smaps = self.get_anon_smaps_by_pid(self.vm.get_pid())
+
+ # rss = locked on every smap and segment with rss < size exists
+ exists = False
+ for smap in anon_smaps:
+ self.assertTrue(smap['Rss'] == smap['Locked'])
+ if smap['Rss'] < smap['Size']:
+ exists = True
+ self.assertTrue(exists)
+
+ def _parse_anonymous_smaps(self, smaps_raw: str) -> List[Dict[str, int]]:
+ result_segments = []
+ current_segment = {}
+ is_anonymous = False
+
+ for line in smaps_raw.split('\n'):
+ if SMAPS_HEADER_PATTERN.match(line):
+ if current_segment and is_anonymous:
+ result_segments.append(current_segment)
+ current_segment = {}
+ # anonymous segment header looks like this:
+ # 7f3b8d3f0000-7f3b8d3f3000 rw-s 00000000 00:0f 1052
+ # and non anonymous header looks like this:
+ # 7f3b8d3f0000-7f3b8d3f3000 rw-s 00000000 00:0f 1052 [stack]
+ is_anonymous = len(line.split()) == 5
+ elif m := SMAPS_VALUE_PATTERN.match(line):
+ current_segment[m.group(1)] = int(m.group(2))
+
+ if current_segment and is_anonymous:
+ result_segments.append(current_segment)
+
+ return result_segments
+
+ def _get_raw_smaps_by_pid(self, pid: int) -> str:
+ with open(f'/proc/{pid}/smaps', 'r') as f:
+ return f.read()
+
+
+if __name__ == '__main__':
+ MemlockTest.main()
--
2.34.1
