--- a/memory/mozjemalloc/jemalloc.c
+++ b/memory/mozjemalloc/jemalloc.c
@@ -4657,19 +4657,16 @@ arena_dalloc_small(arena_t *arena, arena
 	arena->stats.allocated_small -= size;
 	arena->stats.ndalloc_small++;
 #endif
 }
 
 static void
 arena_dalloc_large(arena_t *arena, arena_chunk_t *chunk, void *ptr)
 {
-	/* Large allocation. */
-	malloc_spin_lock(&arena->lock);
-
 #ifdef MALLOC_FILL
 #ifndef MALLOC_STATS
 	if (opt_poison)
 #endif
 #endif
 	{
 		size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >>
 		    pagesize_2pow;
@@ -4685,17 +4682,16 @@ arena_dalloc_large(arena_t *arena, arena
 		arena->stats.allocated_large -= size;
 #endif
 	}
 #ifdef MALLOC_STATS
 	arena->stats.ndalloc_large++;
 #endif
 
 	arena_run_dalloc(arena, (arena_run_t *)ptr, true);
-	malloc_spin_unlock(&arena->lock);
 }
 
 static inline void
 arena_dalloc(void *ptr, size_t offset)
 {
 	arena_chunk_t *chunk;
 	arena_t *arena;
 	size_t pageind;
@@ -4705,26 +4701,28 @@ arena_dalloc(void *ptr, size_t offset)
 	assert(offset != 0);
 	assert(CHUNK_ADDR2OFFSET(ptr) == offset);
 
 	chunk = (arena_chunk_t *) ((uintptr_t)ptr - offset);
 	arena = chunk->arena;
 	assert(arena != NULL);
 	RELEASE_ASSERT(arena->magic == ARENA_MAGIC);
 
+	malloc_spin_lock(&arena->lock);
 	pageind = offset >> pagesize_2pow;
 	mapelm = &chunk->map[pageind];
 	RELEASE_ASSERT((mapelm->bits & CHUNK_MAP_ALLOCATED) != 0);
 	if ((mapelm->bits & CHUNK_MAP_LARGE) == 0) {
 		/* Small allocation. */
-		malloc_spin_lock(&arena->lock);
 		arena_dalloc_small(arena, chunk, ptr, mapelm);
-		malloc_spin_unlock(&arena->lock);
-	} else
+	} else {
+		/* Large allocation. */
 		arena_dalloc_large(arena, chunk, ptr);
+	}
+	malloc_spin_unlock(&arena->lock);
 }
 
 static inline void
 idalloc(void *ptr)
 {
 	size_t offset;
 
 	assert(ptr != NULL);
@@ -4762,25 +4760,25 @@ arena_ralloc_large_shrink(arena_t *arena
 
 static bool
 arena_ralloc_large_grow(arena_t *arena, arena_chunk_t *chunk, void *ptr,
     size_t size, size_t oldsize)
 {
 	size_t pageind = ((uintptr_t)ptr - (uintptr_t)chunk) >> pagesize_2pow;
 	size_t npages = oldsize >> pagesize_2pow;
 
+#ifdef MALLOC_BALANCE
+	arena_lock_balance(arena);
+#else
+	malloc_spin_lock(&arena->lock);
+#endif
 	RELEASE_ASSERT(oldsize == (chunk->map[pageind].bits & ~pagesize_mask));
 
 	/* Try to extend the run. */
 	assert(size > oldsize);
-#ifdef MALLOC_BALANCE
-	arena_lock_balance(arena);
-#else
-	malloc_spin_lock(&arena->lock);
-#endif
 	if (pageind + npages < chunk_npages && (chunk->map[pageind+npages].bits
 	    & CHUNK_MAP_ALLOCATED) == 0 && (chunk->map[pageind+npages].bits &
 	    ~pagesize_mask) >= size - oldsize) {
 		/*
 		 * The next run is available and sufficiently large.  Split the
 		 * following run, then merge the first part with the existing
 		 * allocation.
 		 */