Re: [PATCH 3/3] ftrace/samples: Add module to test multi direct modify interface

Jiri Olsa
2021-12-06T12:28:57Z

On Mon, Dec 06, 2021 at 12:25:37PM +0100, Heiko Carstens wrote:
> On Mon, Dec 06, 2021 at 12:20:36AM +0100, Jiri Olsa wrote:
> > Adding ftrace-direct-multi-modify.ko kernel module that uses
> > modify_ftrace_direct_multi API. The core functionality is taken
> > from ftrace-direct-modify.ko kernel module and changed to fit
> > multi direct interface.
> >
> > The init function creates kthread that periodically calls
> > modify_ftrace_direct_multi to change the trampoline address
> > for the direct ftrace_ops. The ftrace trace_pipe then shows
> > trace from both trampolines.
> >
> > Also adding SAMPLE_FTRACE_MULTI_DIRECT to enable build of
> > direct multi interface sample modules. It's used in Makefile,
> > but not defined at the moment.
> >
> > Same as for ftrace-direct-multi.ko, the new module is enabled
> > only for x86_64, so there's no need to ifdef the inlined assembly.
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> > samples/Kconfig | 8 ++
> > samples/ftrace/Makefile | 1 +
> > samples/ftrace/ftrace-direct-multi-modify.c | 105 ++++++++++++++++++++
> > 3 files changed, 114 insertions(+)
> > create mode 100644 samples/ftrace/ftrace-direct-multi-modify.c
>
> I think your series is based on something before 5.16-rc2?
>
> Because there are:
> 503e45108451 ("ftrace/samples: add missing Kconfig option for ftrace direct multi sample")
> 890e3dc8bb6e ("ftrace/samples: add s390 support for ftrace direct multi sample")
>
> Which would conflict with your patches.

ah so we have some of the changes already.. I'll pick it up,
rebase and resend

thanks,
jirka