[v2] linux-tool-perf: permit TUI build

Since Linux 3.10, perf's NO_NEWT configuration option simply sets
NO_SLANG=1 and there is no dependency on libnewt.

We already handle NO_SLANG correctly based on whether or not
BR2_PACKAGE_SLANG is selected, so all we accomplish by setting NO_NEWT=1
is disabling perf's TUI when all of the dependencies are available.

To simplify all of this, introduce a new config option to enable the
perf TUI which depends on slang and add a check to prevent building the
TUI on versions which are too old.  The check for NO_SLANG is equivalent
to checking if NO_NEWT is required as NO_SLANG was added in the same
commit that removed the libnewt dependency and deprecated NO_NEWT
(6692c262df4f, "perf tools: Remove dependency on libnewt", 2013-03-28).

Signed-off-by: John Keeping <john@metanate.com>
---
On Mon, 2 Apr 2018 15:07:16 +0200, Yann E. MORIN wrote:

> On 2018-04-02 13:51 +0100, John Keeping spake thusly:
> > Since Linux 3.10, perf's NO_NEWT configuration option simply sets
> > NO_SLANG=1 and there is no dependency on libnewt.
> > 
> > We already handle NO_SLANG correctly based on whether or not
> > BR2_PACKAGE_SLANG is selected, so all we accomplish by setting NO_NEWT=1
> > is disabling perf's TUI when all of the dependencies are available.
> > 
> > Linux 3.10 is almost 5 years old now, so there doesn't seem to be any
> > point in jumping through additional hoops to make perf from older kernel
> > versions build when the newt package is not available.  
> 
> But we still support kernels back to 3.0...
> 
> I would instead suggest you add an option in
> package/linux-tools/Config.in:
> 
>     config BR2_PACKAGE_LINUX_TOOLS_PERF_TUI
> 
> And do a check in package/linux-tools/linux-tool-perf.mk.in whether it
> is valid o not, if needed.

Something like this?  I can't see a neater way of checking the version
dependency and this matches the existing handling of the elfutils
dependency.

 package/linux-tools/Config.in             | 12 ++++++++++++
 package/linux-tools/linux-tool-perf.mk.in | 12 +++++++++---
 2 files changed, 21 insertions(+), 3 deletions(-)

John, All,

On 2018-04-02 15:02 +0100, John Keeping spake thusly:
> Since Linux 3.10, perf's NO_NEWT configuration option simply sets
> NO_SLANG=1 and there is no dependency on libnewt.
> 
> We already handle NO_SLANG correctly based on whether or not
> BR2_PACKAGE_SLANG is selected, so all we accomplish by setting NO_NEWT=1
> is disabling perf's TUI when all of the dependencies are available.
> 
> To simplify all of this, introduce a new config option to enable the
> perf TUI which depends on slang and add a check to prevent building the
> TUI on versions which are too old.  The check for NO_SLANG is equivalent
> to checking if NO_NEWT is required as NO_SLANG was added in the same
> commit that removed the libnewt dependency and deprecated NO_NEWT
> (6692c262df4f, "perf tools: Remove dependency on libnewt", 2013-03-28).
> 
> Signed-off-by: John Keeping <john@metanate.com>
> ---
> On Mon, 2 Apr 2018 15:07:16 +0200, Yann E. MORIN wrote:
> 
> > On 2018-04-02 13:51 +0100, John Keeping spake thusly:
> > > Since Linux 3.10, perf's NO_NEWT configuration option simply sets
> > > NO_SLANG=1 and there is no dependency on libnewt.
> > > 
> > > We already handle NO_SLANG correctly based on whether or not
> > > BR2_PACKAGE_SLANG is selected, so all we accomplish by setting NO_NEWT=1
> > > is disabling perf's TUI when all of the dependencies are available.
> > > 
> > > Linux 3.10 is almost 5 years old now, so there doesn't seem to be any
> > > point in jumping through additional hoops to make perf from older kernel
> > > versions build when the newt package is not available.  
> > 
> > But we still support kernels back to 3.0...
> > 
> > I would instead suggest you add an option in
> > package/linux-tools/Config.in:
> > 
> >     config BR2_PACKAGE_LINUX_TOOLS_PERF_TUI
> > 
> > And do a check in package/linux-tools/linux-tool-perf.mk.in whether it
> > is valid o not, if needed.
> 
> Something like this?  I can't see a neater way of checking the version
> dependency and this matches the existing handling of the elfutils
> dependency.

Yes, that is exactly what I had in mind. :-)

>  package/linux-tools/Config.in             | 12 ++++++++++++
>  package/linux-tools/linux-tool-perf.mk.in | 12 +++++++++---
>  2 files changed, 21 insertions(+), 3 deletions(-)
> 
> diff --git a/package/linux-tools/Config.in b/package/linux-tools/Config.in
> index e3ccd850f9..1d31ce84f1 100644
> --- a/package/linux-tools/Config.in
> +++ b/package/linux-tools/Config.in
> @@ -54,6 +54,18 @@ config BR2_PACKAGE_LINUX_TOOLS_PERF
>  
>  	  https://perf.wiki.kernel.org/
>  
> +if BR2_PACKAGE_LINUX_TOOLS_PERF
> +
> +config BR2_PACKAGE_LINUX_TOOLS_PERF_TUI
> +	bool "enable perf TUI"
> +	select BR2_PACKAGE_SLANG

You forgot to propagate the dependency from slang:

    depends on BR2_USE_MMU # slang

Otherwise, looks fine.

Regards,
Yann E. MORIN.

> +	help
> +	  Enable the TUI interface for perf which requires a TTY and
> +	  enables zooming into DSOs and threads as well as other
> +	  features.
> +
> +endif
> +
>  config BR2_PACKAGE_LINUX_TOOLS_SELFTESTS
>  	bool"selftests"
>  	depends on BR2_PACKAGE_BUSYBOX_SHOW_OTHERS # bash
> diff --git a/package/linux-tools/linux-tool-perf.mk.in b/package/linux-tools/linux-tool-perf.mk.in
> index 69492ba8da..80e00c3c56 100644
> --- a/package/linux-tools/linux-tool-perf.mk.in
> +++ b/package/linux-tools/linux-tool-perf.mk.in
> @@ -22,7 +22,6 @@ PERF_MAKE_FLAGS = \
>  	prefix=/usr \
>  	WERROR=0 \
>  	NO_LIBAUDIT=1 \
> -	NO_NEWT=1 \
>  	NO_GTK2=1 \
>  	NO_LIBPERL=1 \
>  	NO_LIBPYTHON=1 \
> @@ -59,10 +58,10 @@ ifeq ($(BR2_arc),y)
>  PERF_MAKE_FLAGS += NO_BACKTRACE=1
>  endif
>  
> -ifeq ($(BR2_PACKAGE_SLANG),y)
> +ifeq ($(BR2_PACKAGE_LINUX_TOOLS_PERF_TUI),y)
>  PERF_DEPENDENCIES += slang
>  else
> -PERF_MAKE_FLAGS += NO_SLANG=1
> +PERF_MAKE_FLAGS += NO_NEWT=1 NO_SLANG=1
>  endif
>  
>  ifeq ($(BR2_PACKAGE_LIBUNWIND),y)
> @@ -128,6 +127,13 @@ define PERF_BUILD_CMDS
>  			fi \
>  		fi \
>  	fi
> +	$(Q)if test "$(BR2_PACKAGE_LINUX_TOOLS_PERF_TUI)" = "y" ; then \
> +		if ! grep -q NO_SLANG $(LINUX_DIR)/tools/perf/Makefile* ; then \
> +			echo "The perf tool in your kernel cannot be build with the TUI." ; \
> +			echo "Either upgrade your kernel to >= 3.10, or disable the TUI." ; \
> +			exit 1 ; \
> +		fi \
> +	fi
>  	$(TARGET_MAKE_ENV) $(MAKE1) $(PERF_MAKE_FLAGS) \
>  		-C $(LINUX_DIR)/tools/perf O=$(LINUX_DIR)/tools/perf/
>  endef
> -- 
> 2.16.3
>

Hello John,

On Mon, 2 Apr 2018 15:02:49 +0100, John Keeping wrote:
> Since Linux 3.10, perf's NO_NEWT configuration option simply sets
> NO_SLANG=1 and there is no dependency on libnewt.
> 
> We already handle NO_SLANG correctly based on whether or not
> BR2_PACKAGE_SLANG is selected, so all we accomplish by setting NO_NEWT=1
> is disabling perf's TUI when all of the dependencies are available.
> 
> To simplify all of this, introduce a new config option to enable the
> perf TUI which depends on slang and add a check to prevent building the
> TUI on versions which are too old.  The check for NO_SLANG is equivalent
> to checking if NO_NEWT is required as NO_SLANG was added in the same
> commit that removed the libnewt dependency and deprecated NO_NEWT
> (6692c262df4f, "perf tools: Remove dependency on libnewt", 2013-03-28).
> 
> Signed-off-by: John Keeping <john@metanate.com>
> ---
> On Mon, 2 Apr 2018 15:07:16 +0200, Yann E. MORIN wrote:

Applied to master after adding the BR2_USE_MMU, as pointed out by Yann,
and after tweaking a bit the commit title. Thanks!

Thomas