Re: [PATCH v6 2/2] tests/functional: add memlock tests
On 17/04/2025 13.40, Alexandr Moshkov wrote:
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
---
tests/functional/meson.build | 1 +
tests/functional/test_memlock.py | 104 +++
2 files changed, 105 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 00..eaf3d46dec
--- /dev/null
+++ b/tests/functional/test_memlock.py
@@ -0,0 +1,104 @@
+#!/usr/bin/env python3
+#
+# Functional test that check overcommit memlock options
+#
+# Copyright (c) Yandex Technologies LLC, 2025
+#
+# Author:
+# Alexandr Moshkov
+#
+#
+# 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:
+# 7f3b8d3f-7f3b8d3f3000 rw-s 00:0f 1052
+# and non anonymous header looks like this:
+# 7f3b8d3f-7f3b8d3f3000 rw-s 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()
The patch looks basically fine to me, but here you should consider that this
might be running on a non-Linux system, too, I think. So in case the open()
fails, just do a self.skipTest() ?
Thomas
[PATCH v6 2/2] tests/functional: add memlock tests
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
---
tests/functional/meson.build | 1 +
tests/functional/test_memlock.py | 104 +++
2 files changed, 105 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 00..eaf3d46dec
--- /dev/null
+++ b/tests/functional/test_memlock.py
@@ -0,0 +1,104 @@
+#!/usr/bin/env python3
+#
+# Functional test that check overcommit memlock options
+#
+# Copyright (c) Yandex Technologies LLC, 2025
+#
+# Author:
+# Alexandr Moshkov
+#
+#
+# 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:
+# 7f3b8d3f-7f3b8d3f3000 rw-s 00:0f 1052
+# and non anonymous header looks like this:
+# 7f3b8d3f-7f3b8d3f3000 rw-s 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
