[LITMUS^RT] Creating a new plugin problem

[Björn Brandenburg]

> On 8 Apr 2017, at 11:11, Matteo Locatelli <matteo.locatelli1993 at gmail.com> wrote:
> 
> I did what you suggested me, but when I run the new version of litmus a message appears saying "Failed to set new theme Write () failed: no space left on device". If I run the previous version of the kernel I can only see a black screen and nothing appears. Can you help me solve this problem please?
> 
> Regards
> Matteo
> 
> Il 07 Apr 2017 19:01, "Rajarajeswari R" <rajeswarirajasekar29 at gmail.com> ha scritto:
> Hi matteo,
>  After compilation using "make" command in litmus-rt folder ,run these commands also
> 
> fakeroot make-kpkg -j 4 --initrd --append-to-version=-litmusrt kernel_image kernel_headers
> 
> cd ..
> 
> sudo dpkg -i *.deb
> 
> sudo reboot
> 
> when you reboot it,choose the kernel which has been compiled and built recently.
> you will find the DEMO plugin when you run setsched command in liblitmus folder.
> 
> Regards,
> Raji
> 
> On Fri, Apr 7, 2017 at 8:53 PM, Matteo Locatelli <matteo.locatelli1993 at gmail.com> wrote:
> Can you tell me the procedure to reinstall the kernel? Because I think that probably I'm doing something wrong in this step. 
> 
> Regards 
> Matteo 
> 
> Il 07 Apr 2017 13:28, "Björn Brandenburg" <bbb at mpi-sws.org> ha scritto:
> 
> > On 2 Apr 2017, at 19:25, Matteo <matteo.locatelli1993 at gmail.com> wrote:
> >
> > The DEMO plugin isn't in the loaded file, but I can't understand why, it's the first time I'm trying to do something like that. Can you tell me a way to add the plugin? Thanks.
> >
> > Matteo
> >
> > On 02.04.2017 18:10, Namhoon Kim wrote:
> >> Hi Matteo,
> >>
> >> If you have successfully added DEMO plugin, you should see DEMO plugin in /proc/litmus/plugins/loaded. Can you check the loaded plugins?
> >>
> >> Namhoon
> >>
> >> On Sun, Apr 2, 2017 at 11:50 AM, Matteo <matteo.locatelli1993 at gmail.com> wrote:
> >> Hi everyone, I want to develop a new plugin for LITMUS^RT, so I downloaded the virtual image found on the website and I started to follow the tutorial that I found on the wiki. I'm currently stuck on step 2: I created the sched_demo.c file (copying the code from the tutorial), added sched_demo.o to the obj-y list in the Makefile located in the litmus folder and compiled the kernel using make in the litmus-rt folder. When I try to run the instruction setsched DEMO, it returns me this error:
> >>
> >> Error: Cannot write to /proc/litmus/active_plugin. Do you have root privileges?
> >> Error: Setting new plugin failed.
> >> Are there any active real-time tasks?
> >>
> >> Can you tell me what I am doing wrong? Thanks.
> >> Matteo Locatelli
> 
> 
> Did you install the new kernel and reboot?
> What does uname -a say?
> Does dmesg say anything about the demo plugin being loaded?


Dear Matteo,

these issues are unrelated to LITMUS^RT. Since LITMUS^RT is based on the Linux kernel, some familiarity with working with Linux is required. Before starting to work with the LITMUS^RT patch, it is thus highly recommended to compile, install, and make work a couple of non-LITMUS^RT kernels. Once you have a working configuration and workflow for installing regular Linux kernels (there are _plenty_ of how-to guidelines available online), moving to LITMUS^RT will be easy: LITMUS^RT can be installed just like any other Linux kernel.

Best,
Björn