CI: run tests with both Pageserver VirtualFile IO engines

- control via env var PAGESERVER_VIRTUAL_FILE_IO_ENGINE
- if an io engine other than std-fs is used, it shows up in the test
  name; this is so that we can continue to use the flaky tests database
- raise memlock limit & while at it also raise shmem limit
  for the Rust tests. It's need on our older runners that use
  an older 5.10.X LTS kernel, where io_uring SQ and CQ still
  counted towards the rlimit, see
  https://github.com/neondatabase/neon/issues/6373#issuecomment-1905814391
  for details.

Co-authored-by: Alexander Bayandin <alexander@neon.tech>

test_runner/fixtures/neon_fixtures.py

@@ -1197,6 +1197,7 @@ def _shared_simple_env(
     neon_binpath: Path,
     pg_distrib_dir: Path,
     pg_version: PgVersion,
+    pageserver_virtual_file_io_engine: str,
 ) -> Iterator[NeonEnv]:
     """
     # Internal fixture backing the `neon_simple_env` fixture. If TEST_SHARED_FIXTURES
@@ -1226,6 +1227,7 @@ def _shared_simple_env(
         preserve_database_files=pytestconfig.getoption("--preserve-database-files"),
         test_name=request.node.name,
         test_output_dir=test_output_dir,
+        pageserver_virtual_file_io_engine=pageserver_virtual_file_io_engine,
     ) as builder:
         env = builder.init_start()
 
@@ -1264,6 +1266,7 @@ def neon_env_builder(
     request: FixtureRequest,
     test_overlay_dir: Path,
     top_output_dir: Path,
+    pageserver_virtual_file_io_engine: str,
 ) -> Iterator[NeonEnvBuilder]:
     """
     Fixture to create a Neon environment for test.
@@ -1293,6 +1296,7 @@ def neon_env_builder(
         broker=default_broker,
         run_id=run_id,
         preserve_database_files=pytestconfig.getoption("--preserve-database-files"),
+        pageserver_virtual_file_io_engine=pageserver_virtual_file_io_engine,
         test_name=request.node.name,
         test_output_dir=test_output_dir,
         test_overlay_dir=test_overlay_dir,

test_runner/fixtures/parametrize.py

@@ -8,7 +8,7 @@ from _pytest.python import Metafunc
 from fixtures.pg_version import PgVersion
 
 """
-Dynamically parametrize tests by Postgres version and build type (debug/release/remote)
+Dynamically parametrize tests by Postgres version, build type (debug/release/remote), and possibly by other parameters
 """
 
 
@@ -31,11 +31,12 @@ def build_type(request: FixtureRequest) -> Optional[str]:
     return None
 
 
-def pytest_generate_tests(metafunc: Metafunc):
-    # Do not parametrize performance tests yet, we need to prepare grafana charts first
-    if "test_runner/performance" in metafunc.definition._nodeid:
-        return
+@pytest.fixture(scope="function", autouse=True)
+def pageserver_virtual_file_io_engine(request: FixtureRequest) -> Optional[str]:
+    return None
 
+
+def pytest_generate_tests(metafunc: Metafunc):
     if (v := os.environ.get("DEFAULT_PG_VERSION")) is None:
         pg_versions = [version for version in PgVersion if version != PgVersion.NOT_SET]
     else:
@@ -46,5 +47,12 @@ def pytest_generate_tests(metafunc: Metafunc):
     else:
         build_types = [bt.lower()]
 
-    metafunc.parametrize("build_type", build_types)
-    metafunc.parametrize("pg_version", pg_versions, ids=map(lambda v: f"pg{v}", pg_versions))
+    # Do not parametrize performance tests yet by Postgres version or build type, we need to prepare grafana charts first
+    if "test_runner/performance" not in metafunc.definition._nodeid:
+        metafunc.parametrize("build_type", build_types)
+        metafunc.parametrize("pg_version", pg_versions, ids=map(lambda v: f"pg{v}", pg_versions))
+
+    # A hacky way to parametrize tests only for `pageserver_virtual_file_io_engine=tokio-epoll-uring`
+    # And do not change test name for default `pageserver_virtual_file_io_engine=std-fs` to keep tests statistics
+    if (io_engine := os.environ.get("PAGESERVER_VIRTUAL_FILE_IO_ENGINE", "")) not in ("", "std-fs"):
+        metafunc.parametrize("pageserver_virtual_file_io_engine", [io_engine])