diff --git a/[refs] b/[refs]
index 4ceeeaac4cf8..61a109bdc29e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 48b83d2425d7781bb625b1c37b5f2a8963b6e23b
+refs/heads/master: 22eecde2f9034764a3fd095eecfa3adfb8ec9a98
diff --git a/trunk/arch/um/Makefile b/trunk/arch/um/Makefile
index dbeab15e7bb7..01b97c19a8ba 100644
--- a/trunk/arch/um/Makefile
+++ b/trunk/arch/um/Makefile
@@ -77,7 +77,10 @@ include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
 KERNEL_DEFINES = $(strip -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \
 			 -Dmktime=kernel_mktime $(ARCH_KERNEL_DEFINES))
 KBUILD_CFLAGS += $(KERNEL_DEFINES)
-KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time,)
+# 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:
+KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then \
+			echo $(call cc-option,-fno-unit-at-a-time); fi ;)
 
 PHONY += linux