[LITMUS^RT] Can not register DEMO Scheduler Plugin in LITMUS^RT

[Björn Brandenburg]

On 27.12.2013, at 01:33, Sanjib Das <cnt.sanjib at googlemail.com> wrote:

> Dear Concern,
> First of all Wish you all a Happy New Year,
> I am still trying to solve the problem registering DEMO plug in a single boot Ubuntu PC but I am running out of ideas. As its one part of my education part a soon possible reply will help a lot. 
> 
> Another information about KVM. I am trying to load an kvm image of ubuntu which already included  with litmust patch. But it requires  an user name and password. So, this information is also required .
> 
> Thanks in advance
> 
> Sanjib   
> 
> 
> On Thu, Dec 19, 2013 at 11:04 PM, Sanjib Das <cnt.sanjib at googlemail.com> wrote:
> Hi,
> If I am not mistaken I have followed the steps from litmus-rt wiki. Codes are just copy pest.
> I have attached my sched_demo.c.
> 
> Thanks in advance 
> 
> Sanjib
> 
> 
> On Thu, Dec 19, 2013 at 9:00 PM, Björn Brandenburg <bbb at mpi-sws.org> wrote:
> 
> On 19 Dec 2013, at 00:55, Sanjib Das <cnt.sanjib at googlemail.com> wrote:
> > I have added sched_demo.o in the Makefile, and compile kernel using 'make bzImage' then make modules following make module_install and make install. then update grub for the new kernel version.
> > After reboot your given command gives the following output::
> > sdas at sd-lab:~$ dmesg | grep 'Registering'
> > [    0.427574] PM: Registering ACPI NVS region [mem 0x77758000-0x777befff] (421888 bytes)
> > [    3.448036] Registering LITMUS^RT plugin Linux.
> > [    3.448188] Registering LITMUS^RT plugin GSN-EDF.
> > [    3.448192] Registering LITMUS^RT plugin PSN-EDF.
> > [    3.448205] Registering LITMUS^RT plugin P-FP.
> > [    3.448206] Registering LITMUS^RT plugin C-EDF.
> > sdas at sd-lab:~$
> >
> 
> Weird. Can you please post your sched_demo.c?
> 
> Thanks,
> Björn


Dear Sanjib,

somehow your plugin file is not properly hooked up to the build system. The kernel should definitely print "Registering LITMUS^RT plugin DEMO” during the boot process, regardless of whether the plugin is correctly implemented or not. You can verify this yourself by inspecting the implementation of register_sched_plugin() in litmus/sched_plugin.c. You’ll need to figure out why demo file is not being linked into the kernel image. As a start, you should verify that it is being compiled (e.g., by introducing a syntax error and verifying that the build fails).

Regards,
Björn