1 files changed, 7 insertions, 0 deletions

diff --git a/arch/um/Makefile-i386 b/arch/um/Makefile-i386
index 561e373bd850..302cbe504543 100644
--- a/arch/um/Makefile-i386
+++ b/arch/um/Makefile-i386
@@ -32,4 +32,11 @@ cflags-y += $(call cc-option,-mpreferred-stack-boundary=2)
 # an unresolved reference.
 cflags-y += -ffreestanding
 
+# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
+# a lot more stack due to the lack of sharing of stacklots.  Also, gcc
+# 4.3.0 needs -funit-at-a-time for extern inline functions.
+KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then \
+                        echo $(call cc-option,-fno-unit-at-a-time); \
+                        else echo $(call cc-option,-funit-at-a-time); fi ;)
+
 KBUILD_CFLAGS += $(cflags-y)