[dpdk-dev] JSON compilation in examples/vm_power_manager

[Hunt, David]

Hi Thomas,


On 1/11/2018 10:47 AM, Thomas Monjalon wrote:
> Hi Dave,
>
> In examples/vm_power_manager/Makefile, jansson lib availability
> is detected with pkg-config --exists.
> As we have seen for telemetry lib, we can detect jansson
> for the wrong arch and enable it no matter the arch being compiled.
>
> The solution was to disable it in Makefile and use meson for
> reliable dependency detection.
>
> Would you like to do the same for this app?
>
>

I would prefer that if the user is cross compiling or selecting a 
different target, that they
set up their environment variables correctly for compilation. In this 
case, the user should set
PKG_CONFIG_LIBDIR to point to the relevant library folder, e.g. for an 
i386 build:

export PKG_CONFIG_LIBDIR=/usr/lib/i386-linux-gnu/pkgconfig

That way the Makefile will pick up the correct library if it's present, 
and build without the library
if it is not present.

Also, if DPDK is being built natively on a machine, the makefile should 
be fine as it is.

So, how about I create a patch to add a few lines to the docs around 
compilation
describing how to set up PKG_CONFIG_LIBDIR correctly for the 
vm_power_manager
sample app?

Regards,
Dave.