Merge pull request #21120 from vespa-engine/revert-21119-revert-21118-balder/wire-in-mallopt-control-of-vespamalloc-skeletonv7.541.24

Revert "Revert "Wire in mallopt(in param, int value) interface in vespamalloc and ver…""

1 files changed, 23 insertions, 0 deletions

diff --git a/staging_vespalib/src/vespa/vespalib/util/malloc_mmap_guard.cpp b/staging_vespalib/src/vespa/vespalib/util/malloc_mmap_guard.cpp
new file mode 100644
index 00000000000..0ced160fda2
--- /dev/null
+++ b/staging_vespalib/src/vespa/vespalib/util/malloc_mmap_guard.cpp
@@ -0,0 +1,23 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+#include "malloc_mmap_guard.h"
+#include <vespa/vespalib/util/size_literals.h>
+#include <malloc.h>
+#include <limits>
+#include <cassert>
+
+namespace vespalib {
+
+MallocMmapGuard::MallocMmapGuard(size_t mmapLimit) :
+    _threadId(std::this_thread::get_id())
+{
+    int limit = mmapLimit <= std::numeric_limits<int>::max() ? mmapLimit : std::numeric_limits<int>::max();
+    mallopt(M_MMAP_THRESHOLD, limit);
+}
+
+MallocMmapGuard::~MallocMmapGuard()
+{
+    assert(_threadId == std::this_thread::get_id());
+    mallopt(M_MMAP_THRESHOLD, 1_Gi);
+}
+
+}