[PATCH v5 0/2] tests/functional: add memlock tests

[PATCH v5 0/2] tests/functional: add memlock tests

[Alexandr Moshkov]

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.

---

v4 -> v5:
* refactor skipLockedMemoryTest decorator: using resource.getrlimit()
  function instead of spawning a process

v3 -> v4:
* add skipLockedMemoryTest decorator to skip test if system's locked
  memory limit is below the required threashold;
* add to MemlockTest skipLockedMemoryTest decorator with 2 GB limit.

v2 -> v3:
Move tests to tests/functional dir, as the tests/avocado dir is being phased out.
v2 was [PATCH v2] tests/avocado: add memlock tests.
Supersedes: <20250414075702.9248-1-dtalexundeer@yandex-team.ru>

v1 -> v2:
In the previous send, i forgot to specify new patch version (v2)
So i resend previous patch with version specified.


Alexandr Moshkov (2):
  tests/functional: add skipLockedMemoryTest decorator
  tests/functional: add memlock tests

 tests/functional/meson.build             |   1 +
 tests/functional/qemu_test/__init__.py   |   2 +-
 tests/functional/qemu_test/decorators.py |  18 ++++
 tests/functional/test_memlock.py         | 102 +++++++++++++++++++++++
 4 files changed, 122 insertions(+), 1 deletion(-)
 create mode 100755 tests/functional/test_memlock.py

-- 
2.34.1

[PATCH v5 1/2] tests/functional: add skipLockedMemoryTest decorator

[Alexandr Moshkov]

Used in future commit to skipping execution of a tests if the system's
locked memory limit is below the required threshold.

Signed-off-by: Alexandr Moshkov <dtalexundeer@yandex-team.ru>
---
 tests/functional/qemu_test/__init__.py   |  2 +-
 tests/functional/qemu_test/decorators.py | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/tests/functional/qemu_test/__init__.py b/tests/functional/qemu_test/__init__.py
index af41c2c6a2..6e666a059f 100644
--- a/tests/functional/qemu_test/__init__.py
+++ b/tests/functional/qemu_test/__init__.py
@@ -15,6 +15,6 @@
 from .linuxkernel import LinuxKernelTest
 from .decorators import skipIfMissingCommands, skipIfNotMachine, \
     skipFlakyTest, skipUntrustedTest, skipBigDataTest, skipSlowTest, \
-    skipIfMissingImports, skipIfOperatingSystem
+    skipIfMissingImports, skipIfOperatingSystem, skipLockedMemoryTest
 from .archive import archive_extract
 from .uncompress import uncompress
diff --git a/tests/functional/qemu_test/decorators.py b/tests/functional/qemu_test/decorators.py
index 50d29de533..c0d1567b14 100644
--- a/tests/functional/qemu_test/decorators.py
+++ b/tests/functional/qemu_test/decorators.py
@@ -5,6 +5,7 @@
 import importlib
 import os
 import platform
+import resource
 from unittest import skipIf, skipUnless
 
 from .cmd import which
@@ -131,3 +132,20 @@ def skipIfMissingImports(*args):
 
     return skipUnless(has_imports, 'required import(s) "%s" not installed' %
                                    ", ".join(args))
+
+'''
+Decorator to skip execution of a test if the system's
+locked memory limit is below the required threshold.
+Takes required locked memory threshold in kB.
+Example:
+
+  @skipLockedMemoryTest(2_097_152)
+'''
+def skipLockedMemoryTest(locked_memory):
+    # get memlock hard limit in bytes
+    _, ulimit_memory = resource.getrlimit(resource.RLIMIT_MEMLOCK)
+
+    return skipUnless(
+        ulimit_memory == resource.RLIM_INFINITY or ulimit_memory >= locked_memory * 1024,
+        f'Test required {locked_memory} kB of available locked memory',
+    )
-- 
2.34.1

[PATCH v5 2/2] tests/functional: add memlock tests

[Alexandr Moshkov]

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 <dtalexundeer@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 <dtalexundeer@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

Re: [PATCH v5 2/2] tests/functional: add memlock tests

[Daniel P. Berrangé]

On Thu, Apr 17, 2025 at 04:13:21PM +0500, 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 <dtalexundeer@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 @@

Forgot to say last time this also needs

  #!/usr/bin/env python3

> +# Functional test that check overcommit memlock options
> +#
> +# Copyright (c) Yandex Technologies LLC, 2025
> +#
> +# Author:
> +#  Alexandr Moshkov <dtalexundeer@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
> 

With regards,
Daniel
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