Decommit instance memory after a runtime call on Linux (#8998)

* Decommit instance memory after a runtime call on Linux * Update documentation for the test * Remove unfinished comment * Use saturating_sub. Also update the doc comment. * Precise RSS tracking in the test Instead of tracking RSS for the whole process we just look at the particular mapping that is associated with the linear memory of the runtime instance * Remove unused import * Fix unused imports * Fix the unused imports error for good * Rollback an accidental change to benches * Fix the test * Remove now unneeded code
2026-04-26 13:27:57 +00:00 · 2021-06-14 22:07:06 +01:00
parent 65d3d5d4ab
commit 3df32a5411
10 changed files with 260 additions and 1 deletions
@@ -0,0 +1,73 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2021 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! Tests that are only relevant for Linux.
+
+// Constrain this only to wasmtime for the time being. Without this rustc will complain on unused
+// imports and items. The alternative is to plop `cfg(feature = wasmtime)` everywhere which seems
+// borthersome.
+#![cfg(feature = "wasmtime")]
+
+use crate::WasmExecutionMethod;
+use super::mk_test_runtime;
+use codec::Encode as _;
+
+mod smaps;
+
+use self::smaps::Smaps;
+
+#[test]
+fn memory_consumption_compiled() {
+	// This aims to see if linear memory stays backed by the physical memory after a runtime call.
+	//
+	// For that we make a series of runtime calls, probing the RSS for the VMA matching the linear
+	// memory. After the call we expect RSS to be equal to 0.
+
+	let runtime = mk_test_runtime(WasmExecutionMethod::Compiled, 1024);
+
+	let instance = runtime.new_instance().unwrap();
+	let heap_base = instance
+		.get_global_const("__heap_base")
+		.expect("`__heap_base` is valid")
+		.expect("`__heap_base` exists")
+		.as_i32()
+		.expect("`__heap_base` is an `i32`");
+
+	fn probe_rss(instance: &dyn sc_executor_common::wasm_runtime::WasmInstance) -> usize {
+		let base_addr = instance.linear_memory_base_ptr().unwrap() as usize;
+		Smaps::new().get_rss(base_addr).expect("failed to get rss")
+	}
+
+	instance
+		.call_export(
+			"test_dirty_plenty_memory",
+			&(heap_base as u32, 1u32).encode(),
+		)
+		.unwrap();
+	let probe_1 = probe_rss(&*instance);
+	instance
+		.call_export(
+			"test_dirty_plenty_memory",
+			&(heap_base as u32, 1024u32).encode(),
+		)
+		.unwrap();
+	let probe_2 = probe_rss(&*instance);
+
+	assert_eq!(probe_1, 0);
+	assert_eq!(probe_2, 0);
+}