From 06a69d18fa9bb5d19625a8b5411c67b40d35fe78 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Wed, 17 Jun 2020 21:05:21 -0500
Subject: [PATCH] Disable static memory under QEMU on CI (#1895)

* Enable the spec::simd::simd_align test for AArch64

Copyright (c) 2020, Arm Limited.

* Disable static memory under QEMU on CI

This commit disables the usage of "static" memory on CI and instead
forces all memories to be "dynamic" meaning that they reserve much
smaller chunks of memory. This causes the QEMU process's memory to
drastically drop (10GiB -> 600MiB) and should allow us to keep enabling
tests without hitting the OOM killer on CI.

Closes #1871 (includes that)
Closes #1893

* Fix typo

Co-authored-by: Anton Kirilov <anton.kirilov@arm.com>
---
 .github/workflows/main.yml |  4 ++++
 build.rs                   |  1 +
 tests/all/wast.rs          | 13 +++++++++++++
 3 files changed, 18 insertions(+)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index d1485a34a75e..7143392fe0f9 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -327,6 +327,10 @@ jobs:
         upcase=$(echo ${{ matrix.target }} | awk '{ print toupper($0) }' | sed 's/-/_/g')
         echo ::set-env name=CARGO_TARGET_${upcase}_RUNNER::$HOME/qemu/bin/${{ matrix.qemu }}
         echo ::set-env name=CARGO_TARGET_${upcase}_LINKER::${{ matrix.gcc }}
+
+        # See comments in the source for why we enable this during QEMU
+        # emulation.
+        echo ::set-env name=WASMTIME_TEST_NO_HOG_MEMORY::1
       if: matrix.target != '' && matrix.os == 'ubuntu-latest'
 
     # Install wasm32-wasi target in order to build wasi-common's integration
diff --git a/build.rs b/build.rs
index 3cbcac678e1d..3118925b7718 100644
--- a/build.rs
+++ b/build.rs
@@ -181,6 +181,7 @@ fn ignore(testsuite: &str, testname: &str, strategy: &str) -> bool {
         },
         "Cranelift" => match (testsuite, testname) {
             ("simd", "simd_address") => return false,
+            ("simd", "simd_align") => return false,
             ("simd", "simd_bitwise") => return false,
             ("simd", "simd_boolean") => return false,
             ("simd", "simd_i8x16_cmp") => return false,
diff --git a/tests/all/wast.rs b/tests/all/wast.rs
index 8e3ed9743cd8..d7e267435faf 100644
--- a/tests/all/wast.rs
+++ b/tests/all/wast.rs
@@ -25,6 +25,19 @@ fn run_wast(wast: &str, strategy: Strategy) -> anyhow::Result<()> {
         .strategy(strategy)?
         .cranelift_debug_verifier(true);
 
+    // By default we'll allocate huge chunks (6gb) of the address space for each
+    // linear memory. This is typically fine but when we emulate tests with QEMU
+    // it turns out that it causes memory usage to balloon massively. Leave a
+    // knob here so on CI we can cut down the memory usage of QEMU and avoid the
+    // OOM killer.
+    //
+    // Locally testing this out this drops QEMU's memory usage running this
+    // tests suite from 10GiB to 600MiB. Previously we saw that crossing the
+    // 10GiB threshold caused our processes to get OOM killed on CI.
+    if std::env::var("WASMTIME_TEST_NO_HOG_MEMORY").is_ok() {
+        cfg.static_memory_maximum_size(0);
+    }
+
     let store = Store::new(&Engine::new(&cfg));
     let mut wast_context = WastContext::new(store);
     wast_context.register_spectest()?;