- Add control of M_MMAP_THRESHOLD with environment variable VESPA_MALLOC_MMAP_THRESHOLD.

- Reduce default from 1G to 64M.

3 files changed, 21 insertions, 5 deletions

diff --git a/vespamalloc/src/vespamalloc/malloc/threadlist.hpp b/vespamalloc/src/vespamalloc/malloc/threadlist.hpp
index 743090a4e12..e22b93c48fe 100644
--- a/vespamalloc/src/vespamalloc/malloc/threadlist.hpp
+++ b/vespamalloc/src/vespamalloc/malloc/threadlist.hpp
@@ -2,9 +2,14 @@
 #pragma once
 
 #include "threadlist.h"
+#include <malloc.h>
 
 namespace vespamalloc {
 
+namespace {
+    const char * VESPA_MALLOC_MMAP_THRESHOLD = "VESPA_MALLOC_MMAP_THRESHOLD";
+}
+
 template <typename MemBlockPtrT, typename ThreadStatT>
 ThreadListT<MemBlockPtrT, ThreadStatT>::ThreadListT(AllocPool & allocPool, MMapPool & mmapPool) :
     _isThreaded(false),
@@ -13,8 +18,14 @@ ThreadListT<MemBlockPtrT, ThreadStatT>::ThreadListT(AllocPool & allocPool, MMapP
     _allocPool(allocPool),
     _mmapPool(mmapPool)
 {
+    const char * mmapThresholdS = getenv(VESPA_MALLOC_MMAP_THRESHOLD);
+    int mmapThreshold = (mmapThresholdS != nullptr)
+            ? strtol(mmapThresholdS, nullptr, 0)
+            : MMAP_LIMIT_DEFAULT;
     for (size_t i = 0; i < getMaxNumThreads(); i++) {
-        _threadVector[i].setPool(_allocPool, _mmapPool);
+        auto & thread = _threadVector[i];
+        thread.setPool(_allocPool, _mmapPool);
+        thread.mallopt(M_MMAP_THRESHOLD, mmapThreshold);
     }
 }
 
diff --git a/vespamalloc/src/vespamalloc/malloc/threadpool.h b/vespamalloc/src/vespamalloc/malloc/threadpool.h
index 30ece02ba29..750833084ca 100644
--- a/vespamalloc/src/vespamalloc/malloc/threadpool.h
+++ b/vespamalloc/src/vespamalloc/malloc/threadpool.h
@@ -9,6 +9,10 @@
 
 namespace vespamalloc {
 
+constexpr int MMAP_LIMIT_MIN     =   0x100000; //  1M
+constexpr int MMAP_LIMIT_DEFAULT =  0x4000000; // 64M
+constexpr int MMAP_LIMIT_MAX     = 0x40000000; //  1G
+
 template <typename MemBlockPtrT, typename ThreadStatT >
 class ThreadPoolT
 {
diff --git a/vespamalloc/src/vespamalloc/malloc/threadpool.hpp b/vespamalloc/src/vespamalloc/malloc/threadpool.hpp
index b5a283f6600..e62fa0f2fdf 100644
--- a/vespamalloc/src/vespamalloc/malloc/threadpool.hpp
+++ b/vespamalloc/src/vespamalloc/malloc/threadpool.hpp
@@ -7,8 +7,10 @@
 namespace vespamalloc {
 
 namespace {
-    constexpr size_t MMAP_LIMIT_MIN = 0x100000; // 1M
-    constexpr size_t MMAP_LIMIT_MAX = 0x40000000; // 1G
+    size_t
+    sanitizeMMapThreshold(int threshold) {
+        return std::min(MMAP_LIMIT_MAX, std::max(MMAP_LIMIT_MIN, threshold));
+    }
 }
 
 template <typename MemBlockPtrT, typename ThreadStatT>
@@ -112,9 +114,8 @@ ThreadPoolT<MemBlockPtrT, ThreadStatT>::~ThreadPoolT() = default;
 
 template <typename MemBlockPtrT, typename ThreadStatT >
 int ThreadPoolT<MemBlockPtrT, ThreadStatT>::mallopt(int param, int value) {
-    size_t limit = value;
     if (param == M_MMAP_THRESHOLD) {
-        _mmapLimit = std::min(MMAP_LIMIT_MAX, std::max(MMAP_LIMIT_MIN, limit));
+        _mmapLimit = sanitizeMMapThreshold(value);
         return 1;
     }
     return 0;