Re: [PATCH] powerpc/xmon: Exclude all of xmon/ from ftrace

Hi Michael,
Sorry -- was off since last week.

On 2017/08/15 08:04PM, Michael Ellerman wrote:

Michael Ellerman [off-list ref] writes:

quoted

"Naveen N. Rao" [off-list ref] writes:

quoted

diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
index 0b2f771593eb..5f95af64cb8f 100644
--- a/arch/powerpc/xmon/Makefile
+++ b/arch/powerpc/xmon/Makefile

@@ -7,6 +7,19 @@ UBSAN_SANITIZE := n
 
 ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
 
+ifdef CONFIG_FUNCTION_TRACER
+CFLAGS_REMOVE_xmon.o	= -mno-sched-epilog $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_nonstdio.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
+ifdef CONFIG_XMON_DISASSEMBLY
+CFLAGS_REMOVE_ppc-dis.o	= -mno-sched-epilog $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_ppc-opc.o	= -mno-sched-epilog $(CC_FLAGS_FTRACE)
+ifdef CONFIG_SPU_BASE
+CFLAGS_REMOVE_spu-dis.o	= -mno-sched-epilog $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_spu-opc.o	= -mno-sched-epilog $(CC_FLAGS_FTRACE)
+endif
+endif
+endif

Urk.

We want to disable it for everything in the directory, so can you do
something like:

  ORIG_CFLAGS := $(KBUILD_CFLAGS)
  KBUILD_CFLAGS = $(subst $(CC_FLAGS_FTRACE),,$(ORIG_CFLAGS))

Yes:

  # Disable ftrace for the entire directory
  ORIG_CFLAGS := $(KBUILD_CFLAGS)
  KBUILD_CFLAGS = $(subst -mno-sched-epilog,,$(subst $(CC_FLAGS_FTRACE),,$(ORIG_CFLAGS)))

Seems to work.

Nice -- I had looked for a generic CFLAGS_REMOVE variant, but didn't 
find that. This is much nicer.

Thanks,
Naveen