Commit 581618f2 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 61649881

arch/s390/Kconfig

+0 −13
Original line number Diff line number Diff line
@@ -375,19 +375,6 @@ config PACK_STACK 


	  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"

arch/s390/Makefile

+0 −10
Original line number Diff line number Diff line
@@ -55,22 +55,12 @@ cflags-$(CONFIG_FRAME_POINTER) += -fno-optimize-sibling-calls 
ifeq ($(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)

arch/s390/include/asm/thread_info.h

+0 −5
Original line number Diff line number Diff line
@@ -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)