Re: [Xenomai] Cpusets and the cpu_affinity test

[Henning Schild <henning.schild@siemens.com>]

Am Tue, 2 May 2017 13:13:26 -0700
schrieb Jackson Jones <jackson.jones@gmail.com>:

> > Am Mon, 1 May 2017 14:19:40 -0700
> > schrieb Jackson Jones <jackson.jones@gmail.com>:
> >  
> > > I am having trouble getting the cpu_affinity test to run. The
> > > check for CPU restriction always fails. I have tried to remedy
> > > this by setting the bootargs.
> > >
> > > 1.) I am running an NXP i.MX6 QUAD/DUAL VAR-SOM-MX6 based board
> > > (Variscite var_som_mx6). The kernel is an 4.1.15 NXT/Variscite
> > > kernel (with the BSP patched in). I patched in the
> > > ipipe-core-4.1.15-arm-8.patch.
> > >
> > > 2.) I am running Xenomai 3.0.3
> > >
> > > 3.) The Linux distro is Debian Jessie 8.7 (provided by Variscite
> > > and Linaro)
> > >
> > > 4.) The gcc version is 4.9.2, the libc versioni is 2.19.
> > >
> > > 5.) My configure options are:
> > > ./configure \
> > >     --with-core=cobalt \
> > >     --enable-smp \
> > >     --enable-registry \
> > >     --enable-pshared \
> > >     --enable-dlopen-libs \
> > >     --enable-sanity \
> > >     --disable-tls \
> > >     --enable-valgrind-client \
> > >     --disable-assert
> > >
> > > 6.) Here are the uboot parameters (bootargs):
> > > setenv videoargs 'if hdmidet; then setenv bootargs ${bootargs}
> > > video=mxcfb0:dev=hdmi,1024x768M@60,if=RGB24; else setenv bootargs
> > > ${bootargs} video=mxcfb0:dev=ldb,bpp=32; fi; setenv bootargs
> > > xenomai.supported_cpus=0x0000000f isolcpus=1 ${bootargs}
> > > vmalloc=400M fbmem=32M fbcon=32M gpumem=32M
> > > galcore.contiguousSize=201326592 galcore.contiguousBase=0x00000000
> > > video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off;'
> > >
> > > 7.) I have attached the kernel configuration.
> > >
> > > I noticed that if I leave any cpus out of the supported cpus, the
> > > kernel will hang (e.g. if I put a 7 instead of F).  
> >
> > If you want to use all cores in Xenomai, that parameter is not
> > required and probably should not be set. However the kernel should
> > not hang when you do not include all, but that is probably another
> > issue.
> >
> > Why did you set "isolcpus=1"?  
> 
> I tried using isolcpus after I saw it mentioned in one of the mailing
> lists.
> 
> > And the Mail subject talks about "cpusets", are you using cgroups or
> > where does that term come from?  
> 
> I am using the standard cgroups. I should have used that term instead
> of cpusets. Cpuset is the name of the package in Debian/Ubuntu that
> allows you to create different cgroups. It is useful to machines with
> lots of cores/
> processors.
> 
> >
> > And please tell us how exactly the test fails and what the output
> > is. I guess you are talking about smokey cpu_affinity.
> >
> > testsuite/smokey --run=cpu_affinity --verbose=100  
> 
> I changed the bootargs to:
> 
> setenv videoargs 'if hdmidet; then setenv bootargs ${bootargs}
> video=mxcfb0:dev=hdmi,1024x768M@60,if=RGB24; else setenv bootargs
> ${bootargs} video=mxcfb0:dev=ldb,bpp=32; fi; setenv bootargs
> ${bootargs} vmalloc=400M fbmem=32M fbcon=32M gpumem=32M
> galcore.contiguousSize=201326592 galcore.contiguousBase=0x00000000
> video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off;'
> 
> Here is the output when I run smokey:
> 
> linaro@ZORRO02:/usr/xenomai/bin$ sudo ./smokey --run=cpu_affinity
> --verbose=100
> .. CPU0 is available
> .. CPU1 is available
> .. CPU2 is available
> .. CPU3 is available
> no CPU restriction with xenomai.supported_cpus
> cpu_affinity skipped (no kernel support)
> linaro@ZORRO02:/usr/xenomai/bin$

It does not fail, it is skipped.

> It is failing the test in cpu_affinity.c that starts on line 204:
> 
> 203     /*
> 204      * If there is no CPU restriction on the bootargs
> 205      * (i.e. xenomai.supported_cpus is absent or does not exclude
> 206      * any online CPU), pretend that we have no kernel support for
> 207      * running this test.
> 208      */
> 209     if (cpu < 0) {
> 210         smokey_trace("no CPU restriction with
> xenomai.supported_cpus"); 211         return -ENOSYS;
> 212     }

Sorry i did not look at the test to see what it is actually doing.
Seems it tests the effectiveness of the boot argument
xenomai.supported_cpus. So indeed you should set it to less than all
cpus and run the test again.

If the machine does not boot with less than all, it is now time to
figure out why it hangs during boot. So i guess you should post the
last messages you see on the console when booting with verbose output.

Do you actually need to exclude cpus? If you are hitting a bug here, it
should be fixed. But just giving all cores to cobalt you do not even
encounter the problem and the test does not "fail".

Henning

> Thanks for you help,
> 
> Jackson Jones
> 
> 
> Jackson Jones
> Senior Project Software Engineer
> 
> Stellartech Research Corporation
> 560 Cottonwood Dr.
> Milpitas, CA 95035
> 
> work: 408-331-3159
> cell: 408-835-5334
> Email: jjones@stellartec.com
> Home Email: jackson.jones@gmail.com
> 
> On Tue, May 2, 2017 at 2:23 AM, Henning Schild
> <henning.schild@siemens.com> wrote:
> 
> > Am Tue, 2 May 2017 11:20:39 +0200
> > schrieb Henning Schild <henning.schild@siemens.com>:
> >  
> > > Am Mon, 1 May 2017 14:19:40 -0700
> > > schrieb Jackson Jones <jackson.jones@gmail.com>:
> > >  
> > > > I am having trouble getting the cpu_affinity test to run. The
> > > > check for CPU restriction always fails. I have tried to remedy
> > > > this by setting the bootargs.
> > > >
> > > > 1.) I am running an NXP i.MX6 QUAD/DUAL VAR-SOM-MX6 based board
> > > > (Variscite var_som_mx6). The kernel is an 4.1.15 NXT/Variscite
> > > > kernel (with the BSP patched in). I patched in the
> > > > ipipe-core-4.1.15-arm-8.patch.
> > > >
> > > > 2.) I am running Xenomai 3.0.3
> > > >
> > > > 3.) The Linux distro is Debian Jessie 8.7 (provided by
> > > > Variscite and Linaro)
> > > >
> > > > 4.) The gcc version is 4.9.2, the libc versioni is 2.19.
> > > >
> > > > 5.) My configure options are:
> > > > ./configure \
> > > >     --with-core=cobalt \
> > > >     --enable-smp \
> > > >     --enable-registry \
> > > >     --enable-pshared \
> > > >     --enable-dlopen-libs \
> > > >     --enable-sanity \
> > > >     --disable-tls \
> > > >     --enable-valgrind-client \
> > > >     --disable-assert
> > > >
> > > > 6.) Here are the uboot parameters (bootargs):
> > > > setenv videoargs 'if hdmidet; then setenv bootargs ${bootargs}
> > > > video=mxcfb0:dev=hdmi,1024x768M@60,if=RGB24; else setenv
> > > > bootargs ${bootargs} video=mxcfb0:dev=ldb,bpp=32; fi; setenv
> > > > bootargs xenomai.supported_cpus=0x0000000f isolcpus=1
> > > > ${bootargs} vmalloc=400M fbmem=32M fbcon=32M gpumem=32M
> > > > galcore.contiguousSize=201326592
> > > > galcore.contiguousBase=0x00000000 video=mxcfb1:off
> > > > video=mxcfb2:off video=mxcfb3:off;'
> > > >
> > > > 7.) I have attached the kernel configuration.
> > > >
> > > > I noticed that if I leave any cpus out of the supported cpus,
> > > > the kernel will hang (e.g. if I put a 7 instead of F).  
> > >
> > > If you want to use all cores in Xenomai, that parameter is not
> > > required and probably should not be set. However the kernel should
> > > not hang when you do not include all, but that is probably another
> > > issue.
> > >
> > > Why did you set "isolcpus=1"?
> > >
> > > And please tell us how exactly the test fails and what the output
> > > is. I guess you are talking about smokey cpu_affinity.
> > >
> > > testsuite/smokey --run=cpu_affinity --verbose=100  
> >
> > And the Mail subject talks about "cpusets", are you using cgroups or
> > where does that term come from?
> >  
> > > regards,
> > > Henning
> > >  
> > > > I have read through all the documentation and have not found an
> > > > answer.
> > > >
> > > > Thanks in advance for any help.
> > > >
> > > >
> > > > Sincerely,
> > > >
> > > > Jackson Jones
> > > >
> > > > Stellartech Research Corporation
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