linux/arch/s390/kernel/Makefile
Heiko Carstens e6d60b368b s390/ftrace: hotpatch support for function tracing
Make use of gcc's hotpatch support to generate better code for ftrace
function tracing.
The generated code now contains only a six byte nop in each function
prologue instead of a 24 byte code block which will be runtime patched to
support function tracing.
With the new code generation the runtime overhead for supporting function
tracing is close to zero, while the original code did show a significant
performance impact.

Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-01-29 09:19:25 +01:00

69 lines
2.1 KiB
Makefile

#
# Makefile for the linux kernel.
#
ifdef CONFIG_FUNCTION_TRACER
# Don't trace early setup code and tracing code
CFLAGS_REMOVE_early.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
endif
#
# Passing null pointers is ok for smp code, since we access the lowcore here.
#
CFLAGS_smp.o := -Wno-nonnull
#
# Disable tailcall optimizations for stack / callchain walking functions
# since this might generate broken code when accessing register 15 and
# passing its content to other functions.
#
CFLAGS_stacktrace.o += -fno-optimize-sibling-calls
CFLAGS_dumpstack.o += -fno-optimize-sibling-calls
#
# Pass UTS_MACHINE for user_regset definition
#
CFLAGS_ptrace.o += -DUTS_MACHINE='"$(UTS_MACHINE)"'
CFLAGS_sysinfo.o += -Iinclude/math-emu -Iarch/s390/math-emu -w
obj-y := traps.o time.o process.o base.o early.o setup.o idle.o vtime.o
obj-y += processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
obj-y += debug.o irq.o ipl.o dis.o diag.o sclp.o vdso.o
obj-y += sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o
obj-y += dumpstack.o
obj-y += $(if $(CONFIG_64BIT),entry64.o,entry.o)
obj-y += $(if $(CONFIG_64BIT),reipl64.o,reipl.o)
obj-y += $(if $(CONFIG_64BIT),relocate_kernel64.o,relocate_kernel.o)
extra-y += head.o vmlinux.lds
extra-y += $(if $(CONFIG_64BIT),head64.o,head31.o)
obj-$(CONFIG_MODULES) += s390_ksyms.o module.o
obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_SCHED_BOOK) += topology.o
obj-$(CONFIG_HIBERNATION) += suspend.o swsusp_asm64.o
obj-$(CONFIG_AUDIT) += audit.o
compat-obj-$(CONFIG_AUDIT) += compat_audit.o
obj-$(CONFIG_COMPAT) += compat_linux.o compat_signal.o
obj-$(CONFIG_COMPAT) += compat_wrapper.o $(compat-obj-y)
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_UPROBES) += uprobes.o
ifdef CONFIG_64BIT
obj-$(CONFIG_PERF_EVENTS) += perf_event.o perf_cpum_cf.o perf_cpum_sf.o \
perf_cpum_cf_events.o
obj-y += runtime_instr.o cache.o
endif
# vdso
obj-$(CONFIG_64BIT) += vdso64/
obj-$(CONFIG_32BIT) += vdso32/
obj-$(CONFIG_COMPAT) += vdso32/