diff --git a/bolt/runtime/instr.cpp b/bolt/runtime/instr.cpp
--- a/bolt/runtime/instr.cpp
+++ b/bolt/runtime/instr.cpp
@@ -1471,6 +1471,7 @@
   int FD = openProfile();
 
   BumpPtrAllocator Alloc;
+  Alloc.setMaxSize(0x6400000);
   const uint8_t *FuncDesc = Ctx.FuncDescriptions;
   for (int I = 0, E = __bolt_instr_num_funcs; I < E; ++I) {
     FuncDesc = writeFunctionProfile(FD, Ctx, FuncDesc, Alloc);