Re: [PATCH v3 0/6] tracing: export event trace and trace_marker

From: Mathieu Poirier
Date: Tue Sep 01 2020 - 13:06:12 EST


On Tue, Sep 01, 2020 at 02:37:40PM +0800, Tingwei Zhang wrote:
> Hi Mathieu,
>
> May I know your comments for this patch set?

I do not maintain any of these files.

>
> Thanks,
> Tingwei
>
> On Thu, Aug 13, 2020 at 09:45:46AM +0800, Tingwei Zhang wrote:
> > Ftrace has ability to export trace packets to other destination.
> > Currently, only function trace can be exported. This series extends the
> > support to event trace and trace_maker. STM is one possible destination to
> > export ftrace. Use separate channel for each CPU to avoid mixing up
> > packets
> > from different CPUs together.
> >
> > Change from v2:
> > Change flag definition to BIT(). (Steven)
> > Add comment in stm_ftrace_write() to clarify it's safe to use
> > smp_processor_id() here since preempt is disabled. (Steven)
> >
> > Change from v1:
> > All changes are suggested by Steven Rostedt.
> > User separate flag to control function trace, event trace and trace mark.
> > Allocate channels according to num_possible_cpu() dynamically.
> > Move ftrace_exports routines up so all ftrace can use them.
> >
> > Tingwei Zhang (6):
> > stm class: ftrace: change dependency to TRACING
> > tracing: add flag to control different traces
> > tracing: add trace_export support for event trace
> > tracing: add trace_export support for trace_marker
> > stm class: ftrace: enable supported trace export flag
> > stm class: ftrace: use different channel accroding to CPU
> >
> > drivers/hwtracing/stm/Kconfig | 2 +-
> > drivers/hwtracing/stm/ftrace.c | 7 +-
> > include/linux/trace.h | 7 +
> > kernel/trace/trace.c | 270 ++++++++++++++++++---------------
> > 4 files changed, 159 insertions(+), 127 deletions(-)
> >
> > --
> > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> > a Linux Foundation Collaborative Project
> >