diff --git a/llvm/lib/CodeGen/MachineFunctionSplitter.cpp b/llvm/lib/CodeGen/MachineFunctionSplitter.cpp
--- a/llvm/lib/CodeGen/MachineFunctionSplitter.cpp
+++ b/llvm/lib/CodeGen/MachineFunctionSplitter.cpp
@@ -43,7 +43,7 @@
     PercentileCutoff("mfs-psi-cutoff",
                      cl::desc("Percentile profile summary cutoff used to "
                               "determine cold blocks. Unused if set to zero."),
-                     cl::init(0), cl::Hidden);
+                     cl::init(999950), cl::Hidden);
 
 static cl::opt<unsigned> ColdCountThreshold(
     "mfs-count-threshold",
diff --git a/llvm/test/CodeGen/X86/machine-function-splitter.ll b/llvm/test/CodeGen/X86/machine-function-splitter.ll
--- a/llvm/test/CodeGen/X86/machine-function-splitter.ll
+++ b/llvm/test/CodeGen/X86/machine-function-splitter.ll
@@ -1,5 +1,5 @@
 ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -split-machine-functions | FileCheck %s -check-prefix=MFS-DEFAULTS
-; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -split-machine-functions -mfs-count-threshold=2000 | FileCheck %s --dump-input=always -check-prefix=MFS-OPTS1
+; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -split-machine-functions -mfs-psi-cutoff=0 -mfs-count-threshold=2000 | FileCheck %s --dump-input=always -check-prefix=MFS-OPTS1
 ; RUN: llc < %s -mtriple=x86_64-unknown-linux-gnu -split-machine-functions -mfs-psi-cutoff=950000 | FileCheck %s -check-prefix=MFS-OPTS2
 
 define void @foo1(i1 zeroext %0) nounwind !prof !14 !section_prefix !15 {