s390: remove small stack config option
We've seen repeatedly that 8KB stack size on 64 bit kernels
is not sufficient.
So simply remove the config option.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index eb8fb62..bda6ba6 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -375,19 +375,6 @@
Say Y if you are unsure.
-config SMALL_STACK
- def_bool n
- prompt "Use 8kb for kernel stack instead of 16kb"
- depends on PACK_STACK && 64BIT && !LOCKDEP
- help
- If you say Y here and the compiler supports the -mkernel-backchain
- option the kernel will use a smaller kernel stack size. The reduced
- size is 8kb instead of 16kb. This allows to run more threads on a
- system and reduces the pressure on the memory management for higher
- order page allocations.
-
- Say N if you are unsure.
-
config CHECK_STACK
def_bool y
prompt "Detect kernel stack overflow"
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 7e3ce78..a7d68a4 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -55,22 +55,12 @@
ifeq ($(call cc-option-yn,-mkernel-backchain),y)
cflags-$(CONFIG_PACK_STACK) += -mkernel-backchain -D__PACK_STACK
aflags-$(CONFIG_PACK_STACK) += -D__PACK_STACK
-cflags-$(CONFIG_SMALL_STACK) += -D__SMALL_STACK
-aflags-$(CONFIG_SMALL_STACK) += -D__SMALL_STACK
-ifdef CONFIG_SMALL_STACK
-STACK_SIZE := $(shell echo $$(($(STACK_SIZE)/2)) )
-endif
endif
# new style option for packed stacks
ifeq ($(call cc-option-yn,-mpacked-stack),y)
cflags-$(CONFIG_PACK_STACK) += -mpacked-stack -D__PACK_STACK
aflags-$(CONFIG_PACK_STACK) += -D__PACK_STACK
-cflags-$(CONFIG_SMALL_STACK) += -D__SMALL_STACK
-aflags-$(CONFIG_SMALL_STACK) += -D__SMALL_STACK
-ifdef CONFIG_SMALL_STACK
-STACK_SIZE := $(shell echo $$(($(STACK_SIZE)/2)) )
-endif
endif
ifeq ($(call cc-option-yn,-mstack-size=8192 -mstack-guard=128),y)
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 51035e5..eb5f64d 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -14,13 +14,8 @@
#define THREAD_ORDER 1
#define ASYNC_ORDER 1
#else /* CONFIG_64BIT */
-#ifndef __SMALL_STACK
#define THREAD_ORDER 2
#define ASYNC_ORDER 2
-#else
-#define THREAD_ORDER 1
-#define ASYNC_ORDER 1
-#endif
#endif /* CONFIG_64BIT */
#define THREAD_SIZE (PAGE_SIZE << THREAD_ORDER)