[LITMUS^RT] call for testing 3.10

[Daniel Bristot de Oliveira]

Hi Björn,


On Thu, Jul 18, 2013 at 4:30 PM, Björn Brandenburg <bbb at mpi-sws.org> wrote:

>
> On Jul 18, 2013, at 1:51 PM, Björn Brandenburg <bbb at mpi-sws.org> wrote:
>
>
> On Jul 18, 2013, at 11:49 AM, Björn Brandenburg <bbb at mpi-sws.org> wrote:
>
> the branch on top of 3.10 now runs fine in QEMU. I've given all plugins a
> cursory run, and they seem to work fine. (PFAIR still has the issue
> reported by Hiro, but this is unrelated to the kernel version).
>
> The kernel can be found here:
>
>  https://github.com/LITMUS-RT/litmus-rt/commits/rebased-3.10
>
>
>  Under the (somewhat optimistic) assumption that the 3.10 branch works,
> I've back-ported rebased-3.10 on top of Linux 3.8.13, which is the version
> on top of which the latest PREEMPT_RT version is based. Some minor tweaks
> were required, but it compiles and boots in KVM. For the curious, the
> branch can be found here:
>
>  https://github.com/LITMUS-RT/litmus-rt/tree/rebased-3.8.13
>
> The next step towards low latencies will be to actually squeeze in the
> PREEMPT_RT patch between 3.8.13 and the LITMUS^RT patch series… volunteers
> welcome. :-)
>
>
> Well, turns out there were only few merge conflicts. The branch now
> compiles *with* PREEMPT_RT:
>
> https://github.com/LITMUS-RT/litmus-rt/commits/rebased-3.8.13-rt14
>

I'm on a Ms in automation engineering at UFSC - Brazil, working with real
time Linux, but, my works fits better on PREEMPT_RT, then I'm using it. I
already have made tests with Litmus RT, but I'm not a Litmus RT expert. I'm
interested to help.

At my work (I work on a company too, where I use the PREEMPT_RT too) I have
a Xeon E5620 @ 2.40GHz at my desk, where I compile the rebased-3.8.13.

I used the make localmodconfig, the config file is here:
http://www.bristot.eti.br/files/litmus/3_8_13/config, and I build the
kernel as is on the git.

I got just one compilation problem:

  CC      kernel/sched/core.o
kernel/sched/core.c: In function ‘ttwu_queue’:
kernel/sched/core.c:1417:2: error: implicit declaration of function
‘is_realtime’ [-Werror=implicit-function-declaration]
kernel/sched/core.c: In function ‘finish_task_switch’:
kernel/sched/core.c:1871:32: error: ‘NO_CPU’ undeclared (first use in this
function)
kernel/sched/core.c:1871:32: note: each undeclared identifier is reported
only once for each function it appears in
kernel/sched/core.c: In function ‘__schedule’:
kernel/sched/core.c:3051:2: error: implicit declaration of function
‘srp_ceiling_block’ [-Werror=implicit-function-declaration]
kernel/sched/core.c: In function ‘__sched_setscheduler’:
kernel/sched/core.c:3952:3: error: implicit declaration of function
‘litmus_admit_task’ [-Werror=implicit-function-declaration]
kernel/sched/core.c:4014:3: error: implicit declaration of function
‘litmus_exit_task’ [-Werror=implicit-function-declaration]
kernel/sched/core.c:4021:50: error: ‘NO_CPU’ undeclared (first use in this
function)
cc1: some warnings being treated as errors
make[2]: *** [kernel/sched/core.o] Error 1
make[1]: *** [kernel/sched] Error 2
make: *** [kernel] Error 2
[root at localhost litmus-rt-preempt_rt]#


that I fixed with this:

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 2a6de74..c36d86d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -89,6 +89,7 @@
 #include <litmus/trace.h>
 #include <litmus/sched_trace.h>
 #include <litmus/sched_plugin.h>
+#include <litmus/litmus.h>

 void litmus_tick(struct rq*, struct task_struct*);

the system is running, what's the next step? compile with PREEMPT_RT?



>
> However, it definitely does not work. I'm seeing a recursive lock
> acquisition of a run queue lock via hrtimer_cancel(). Sorting this out will
> take more time than I have now. I think for now my priority will be to get
> the 3.10 tree tested and released; I'll revisit PREEMPT_RT
> afterwards. Anyway, the code is in the repo if anyone wants to take a look.
>
> Thanks,
> Björn
>
>
> _______________________________________________
> litmus-dev mailing list
> litmus-dev at lists.litmus-rt.org
> https://lists.litmus-rt.org/listinfo/litmus-dev
>
>


-- 
Daniel Bristot de Oliveira
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