diff --git a/source/blender/blenkernel/intern/subsurf_ccg.c b/source/blender/blenkernel/intern/subsurf_ccg.c
index 12d7409..18e0ec8 100644
--- a/source/blender/blenkernel/intern/subsurf_ccg.c
+++ b/source/blender/blenkernel/intern/subsurf_ccg.c
@@ -169,6 +169,8 @@ static CCGSubSurf *_getSubSurf(CCGSubSurf *prevSS, int subdivLevels,
 		CCGAllocatorIFC allocatorIFC;
 		CCGAllocatorHDL allocator = BLI_memarena_new(MEM_SIZE_OPTIMAL(1 << 16), "subsurf arena");
 
+		BLI_memarena_set_threadsafe((MemArena *)allocator);
+
 		allocatorIFC.alloc = arena_alloc;
 		allocatorIFC.realloc = arena_realloc;
 		allocatorIFC.free = arena_free;
diff --git a/source/blender/blenlib/BLI_memarena.h b/source/blender/blenlib/BLI_memarena.h
index 8d5a765..a063445 100644
--- a/source/blender/blenlib/BLI_memarena.h
+++ b/source/blender/blenlib/BLI_memarena.h
@@ -57,6 +57,8 @@ void                BLI_memarena_free(struct MemArena *ma) ATTR_NONNULL(1);
 void                BLI_memarena_use_malloc(struct MemArena *ma) ATTR_NONNULL(1);
 void                BLI_memarena_use_calloc(struct MemArena *ma) ATTR_NONNULL(1);
 void                BLI_memarena_use_align(struct MemArena *ma, const size_t align) ATTR_NONNULL(1);
+void                BLI_memarena_set_threadsafe(struct MemArena *ma);
+void                BLI_memarena_clear_threadsafe(struct MemArena *ma);
 void               *BLI_memarena_alloc(struct MemArena *ma, size_t size) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1) ATTR_MALLOC ATTR_ALLOC_SIZE(2);
 void               *BLI_memarena_calloc(struct MemArena *ma, size_t size) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1) ATTR_MALLOC ATTR_ALLOC_SIZE(2);
 
diff --git a/source/blender/blenlib/intern/BLI_memarena.c b/source/blender/blenlib/intern/BLI_memarena.c
index dd0997c..08dd545 100644
--- a/source/blender/blenlib/intern/BLI_memarena.c
+++ b/source/blender/blenlib/intern/BLI_memarena.c
@@ -38,6 +38,7 @@
 #include "BLI_utildefines.h"
 #include "BLI_memarena.h"
 #include "BLI_linklist.h"
+#include "BLI_threads.h"
 #include "BLI_strict_flags.h"
 
 #ifdef WITH_MEM_VALGRIND
@@ -53,6 +54,8 @@ struct MemArena {
 	size_t align;
 
 	bool use_calloc;
+
+	SpinLock *spin_lock, spin_lock_;
 };
 
 MemArena *BLI_memarena_new(const size_t bufsize, const char *name)
@@ -66,6 +69,8 @@ MemArena *BLI_memarena_new(const size_t bufsize, const char *name)
 	VALGRIND_CREATE_MEMPOOL(ma, 0, false);
 #endif
 
+	ma->spin_lock = NULL;
+
 	return ma;
 }
 
@@ -85,6 +90,22 @@ void BLI_memarena_use_align(struct MemArena *ma, const size_t align)
 	ma->align = align;
 }
 
+void BLI_memarena_set_threadsafe(MemArena *ma)
+{
+	if (!ma->spin_lock) {
+		BLI_spin_init(&ma->spin_lock_);
+		ma->spin_lock = &ma->spin_lock_;
+	}
+}
+
+void BLI_memarena_clear_threadsafe(MemArena *ma)
+{
+	if (ma->spin_lock) {
+		ma->spin_lock = NULL;
+		BLI_spin_end(&ma->spin_lock_);
+	}
+}
+
 void BLI_memarena_free(MemArena *ma)
 {
 	BLI_linklist_freeN(ma->bufs);
@@ -93,6 +114,8 @@ void BLI_memarena_free(MemArena *ma)
 	VALGRIND_DESTROY_MEMPOOL(ma);
 #endif
 
+	BLI_memarena_clear_threadsafe(ma);
+
 	MEM_freeN(ma);
 }
 
@@ -117,6 +140,10 @@ void *BLI_memarena_alloc(MemArena *ma, size_t size)
 	 * size up to multiple of 8 */
 	size = PADUP(size, ma->align);
 
+	if (ma->spin_lock) {
+		BLI_spin_lock(ma->spin_lock);
+	}
+
 	if (UNLIKELY(size > ma->cursize)) {
 		if (size > ma->bufsize - (ma->align - 1)) {
 			ma->cursize = PADUP(size + 1, ma->align);
@@ -138,6 +165,10 @@ void *BLI_memarena_alloc(MemArena *ma, size_t size)
 	VALGRIND_MEMPOOL_ALLOC(ma, ptr, size);
 #endif
 
+	if (ma->spin_lock) {
+		BLI_spin_unlock(ma->spin_lock);
+	}
+
 	return ptr;
 }
 
diff --git a/source/blender/modifiers/intern/MOD_meshdeform.c b/source/blender/modifiers/intern/MOD_meshdeform.c
index 584b5b5..364146f 100644
--- a/source/blender/modifiers/intern/MOD_meshdeform.c
+++ b/source/blender/modifiers/intern/MOD_meshdeform.c
@@ -415,6 +415,24 @@ static void deformVerts(ModifierData *md, Object *ob,
 {
 	DerivedMesh *dm = get_dm(ob, NULL, derivedData, NULL, false, false);
 
+
+	if (0) {
+		#include "BLI_memarena.h"
+		#include "PIL_time_utildefines.h"
+		MemArena *ma = BLI_memarena_new(BLI_MEMARENA_STD_BUFSIZE, __func__);
+		int i = 1000000;
+
+		BLI_memarena_set_threadsafe(ma);
+
+		TIMEIT_START(foo);
+		while (i--) {
+			BLI_memarena_alloc(ma, sizeof(int));
+		}
+		TIMEIT_END(foo);
+
+		BLI_memarena_free(ma);
+	}
+
 	modifier_vgroup_cache(md, vertexCos); /* if next modifier needs original vertices */
 
 	meshdeformModifier_do(md, ob, dm, vertexCos, numVerts);