Re: [PATCH 5/8] x86,tracing: Mark debug_stack_{set_zero,reset)() notrace

Peter Zijlstra
2020-02-12T15:05:00Z

On Wed, Feb 12, 2020 at 09:25:39AM -0500, Steven Rostedt wrote:
> On Wed, 12 Feb 2020 10:32:15 +0100
> Peter Zijlstra <peterz@infradead.org> wrote:
>
> > Because do_nmi() must not call into tracing outside of
> > nmi_enter()/nmi_exit(), these functions must be notrace.
> >
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > ---
> > arch/x86/kernel/cpu/common.c | 4 ++--
> > arch/x86/kernel/nmi.c | 6 ++++++
> > 2 files changed, 8 insertions(+), 2 deletions(-)
> >
> > --- a/arch/x86/kernel/cpu/common.c
> > +++ b/arch/x86/kernel/cpu/common.c
>
> This entire file is notrace:
>
> arch/x86/kernel/cpu/Makefile:
>
> CFLAGS_REMOVE_common.o = -pg

Urgh, I hate it that that annotation is so hard to find :/ Also, there
seem to be various flavours of that Makefile magic around.

CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE)

is another variant I encountered.