[v2,01/32] tracing: Allow gcov profiling on only ftrace subsystem
diff mbox series

Message ID 153443697980.23257.9233992547183322108.stgit@devbox
State Superseded
Headers show
Series
  • selftests/ftrace: Improve ftracetest with coverage check
Related show

Commit Message

Masami Hiramatsu Aug. 16, 2018, 4:29 p.m. UTC
Add GCOV_PROFILE_FTRACE to allow gcov profiling
on only files in ftrace subsystem. This kconfig
flag will be used for checking kselftest/ftrace
coverage.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 kernel/trace/Kconfig  |   13 +++++++++++++
 kernel/trace/Makefile |    5 +++++
 2 files changed, 18 insertions(+)

Comments

Steven Rostedt Aug. 20, 2018, 3:32 p.m. UTC | #1
On Fri, 17 Aug 2018 01:29:39 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:

> Add GCOV_PROFILE_FTRACE to allow gcov profiling
> on only files in ftrace subsystem. This kconfig
> flag will be used for checking kselftest/ftrace

Note, I haven't heard of "kconfig flag" as the terminology. Usually, we
just say "config" or "config option".

> coverage.
> 
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> ---
>  kernel/trace/Kconfig  |   13 +++++++++++++
>  kernel/trace/Makefile |    5 +++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> index fd6754b88f87..8decf6d8553a 100644
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -774,6 +774,19 @@ config TRACING_EVENTS_GPIO
>  	help
>  	  Enable tracing events for gpio subsystem
>  
> +config GCOV_PROFILE_FTRACE
> +	bool "Enable GCOV profiling on ftrace subsystem"
> +	depends on GCOV_KERNEL
> +	help
> +	  Enable GCOV profiling on ftrace subsystem for checking
> +	  which functions/lines are tested.
> +
> +	  If unsure, say N.
> +
> +	  Note that on a kernel compiled with this flags, ftrace will be
> +	  significantly run slower. So do not enable it for production
> +	  kernel.


I would rewrite the above as:

	Note that on a kernel compiled with this config, ftrace will
	run significantly slower.

I think we can leave out the production sentence. It should be obvious
from the "significantly slower" part.

Other than that, it looks fine to me.

-- Steve

> +
>  endif # FTRACE
>  
>  endif # TRACING_SUPPORT
> diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
> index 98d53b39a8ee..f81dadbc7c4a 100644
> --- a/kernel/trace/Makefile
> +++ b/kernel/trace/Makefile
> @@ -23,6 +23,11 @@ ifdef CONFIG_TRACING_BRANCHES
>  KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
>  endif
>  
> +# for GCOV coverage profiling
> +ifdef CONFIG_GCOV_PROFILE_FTRACE
> +GCOV_PROFILE := y
> +endif
> +
>  CFLAGS_trace_benchmark.o := -I$(src)
>  CFLAGS_trace_events_filter.o := -I$(src)
>
Steven Rostedt Aug. 20, 2018, 3:33 p.m. UTC | #2
On Mon, 20 Aug 2018 11:32:13 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> Other than that, it looks fine to me.

This patch also seems out of place for the series. Want to resend it
separately, and I'll apply it?

Thanks!

-- Steve
Masami Hiramatsu Aug. 21, 2018, 6:53 a.m. UTC | #3
Hi Steve,

On Mon, 20 Aug 2018 11:33:49 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> On Mon, 20 Aug 2018 11:32:13 -0400
> Steven Rostedt <rostedt@goodmis.org> wrote:
> 
> > Other than that, it looks fine to me.
> 
> This patch also seems out of place for the series.

Yes, this one is the patch for ftrace, not ftracetest.

> Want to resend it
> separately, and I'll apply it?

OK, I'll fix "config" and resend it :)

Thank you,

Patch
diff mbox series

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index fd6754b88f87..8decf6d8553a 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -774,6 +774,19 @@  config TRACING_EVENTS_GPIO
 	help
 	  Enable tracing events for gpio subsystem
 
+config GCOV_PROFILE_FTRACE
+	bool "Enable GCOV profiling on ftrace subsystem"
+	depends on GCOV_KERNEL
+	help
+	  Enable GCOV profiling on ftrace subsystem for checking
+	  which functions/lines are tested.
+
+	  If unsure, say N.
+
+	  Note that on a kernel compiled with this flags, ftrace will be
+	  significantly run slower. So do not enable it for production
+	  kernel.
+
 endif # FTRACE
 
 endif # TRACING_SUPPORT
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 98d53b39a8ee..f81dadbc7c4a 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -23,6 +23,11 @@  ifdef CONFIG_TRACING_BRANCHES
 KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
 endif
 
+# for GCOV coverage profiling
+ifdef CONFIG_GCOV_PROFILE_FTRACE
+GCOV_PROFILE := y
+endif
+
 CFLAGS_trace_benchmark.o := -I$(src)
 CFLAGS_trace_events_filter.o := -I$(src)