Intermediate Commit (2022-02-04 18:03)

.gitlab-ci.yml

@@ -470,3 +470,9 @@ continuation-stealing-locked:
   variables:
     EMPER_CONTINUATION_STEALING_MODE: 'locked'
     EMPER_LOCKED_WS_QUEUE: 'true'
+
+continuation-stealing-madv-free:
+  extends:
+    - .test
+  variables:
+    EMPER_CONTINUATION_STEALING_MADVISE_STACK: 'free'

CONTINUATION-STEALING

+Continuation Stealing Stats:
+- Steal count
+- unmap stats:
+  - how often, how large, how long does it take?
+  - how often was resumable 'false'
+
 TODO:
 - From Nico's branch: WsClV3Queue, WsClV4Queue
 - EMPER_FIBRIL_SYNC, that is FibrilDeque and FibrilLock (which appears to be just a spin lock?) not yet ported. Ask Nico the rationale behind that.

emper/Context.cpp

@@ -41,7 +41,7 @@ void Context::unmap(void* from) const {
 	const size_t PAGE_SIZE_MASK = 4 * 1024 - 1;
 	const uintptr_t start = ((uintptr_t) context + PAGE_SIZE_MASK) & ~PAGE_SIZE_MASK;
 	const uintptr_t end = (uintptr_t) from & ~PAGE_SIZE_MASK;
-
+	const size_t length = end - start;
 	const int advice = []{
 		if constexpr (emper::CONTINUATION_STEALING_MADVISE_STACK == emper::ContinuationStealingMadviseStack::dontneed) {
 			return MADV_DONTNEED;
@@ -50,8 +50,11 @@ void Context::unmap(void* from) const {
 		}
 	}();
 
+
+	LOGD("madvise() start=" << start << ", length=" << length << ", advice=" << advice);
+
 	// NOLINTNEXTLINE(performance-no-int-to-ptr)
-	errno = madvise((void*) start, (end - start), advice);
+	errno = madvise((void*) start, length, advice);
 	if (errno) {
 		DIE_MSG_ERRNO("Unmapping unused stack space failed");
 	}

tests/test-runner/continuation-stealing-test-runner.cpp

+// SPDX-License-Identifier: LGPL-3.0-or-later
+// Copyright © 2022 Florian Schmaus
+#include <cstdlib>
+
+#include "Emper.hpp"
+#include "emper-common.h"
+#include "test-runner.hpp"
+
+auto main(UNUSED_ARG int argc, UNUSED_ARG char* argv[]) -> int {
+	if constexpr (!emper::CONTINUATION_STEALING || emper::BUILD_WITH_CLANG) {
+		exit(77);
+	}
+
+	return testMain();
+}