RFC: Upgrading rt-tests requires numactl

RFC: Upgrading rt-tests requires numactl

[Randy Witt]

While looking into upgrading rt-tests to the latest version, on IRC, John 
Kacur(the maintainer of rt-tests), recommended "that they use 
unstable/devel/latest as the maintained stable branch".

I updated the recipes in 
http://git.yoctoproject.org/cgit.cgi/poky-contrib/commit/?h=rewitt/rt-tests-upgrade&id=551b25918d06c903fff22d76d5683b548c4f2e6f. 
However, I know this won't work as is, due to the issues below.

The latest version of rt-tests requires the numa libraries for compilation via 
this patch https://marc.info/?l=linux-rt-users&m=158335896221530&w=2. rt-tests 
exists in oe-core, but numactl which provides libnuma/numa.h exists in 
meta-openembedded.

Another issue is that ARM is removed from COMPATIBLE_HOST in 
http://cgit.openembedded.org/meta-openembedded/tree/meta-oe/recipes-support/numactl/numactl_git.bb?h=master#n27. 
This may be for legacy reasons, but libnuma can be installed on most 
distributions running on an ARM host. Regardless, it would need to be changed to 
allow for rt-tests on ARM.

I'm therefore trying to determine how to proceed to upgrade rt-tests. These are 
the options I thought of, which are most likely not exhaustive.

1. Bring numactl into oe-core
2. move rt-tests out of oe-core
3. TMy to patch out the numa requirement and carry it forever(doesn't appear to 
be a small task)

Re: [OE-core] RFC: Upgrading rt-tests requires numactl

[Richard Purdie]

On Wed, 2020-09-23 at 10:22 -0700, Randy Witt wrote:
> While looking into upgrading rt-tests to the latest version, on IRC, John 
> Kacur(the maintainer of rt-tests), recommended "that they use 
> unstable/devel/latest as the maintained stable branch".
> 
> I updated the recipes in 
> http://git.yoctoproject.org/cgit.cgi/poky-contrib/commit/?h=rewitt/rt-tests-upgrade&id=551b25918d06c903fff22d76d5683b548c4f2e6f. 
> However, I know this won't work as is, due to the issues below.
> 
> The latest version of rt-tests requires the numa libraries for compilation via 
> this patch https://marc.info/?l=linux-rt-users&m=158335896221530&w=2. rt-tests 
> exists in oe-core, but numactl which provides libnuma/numa.h exists in 
> meta-openembedded.
> 
> Another issue is that ARM is removed from COMPATIBLE_HOST in 
> http://cgit.openembedded.org/meta-openembedded/tree/meta-oe/recipes-support/numactl/numactl_git.bb?h=master#n27. 
> This may be for legacy reasons, but libnuma can be installed on most 
> distributions running on an ARM host. Regardless, it would need to be changed to 
> allow for rt-tests on ARM.
> 
> I'm therefore trying to determine how to proceed to upgrade rt-tests. These are 
> the options I thought of, which are most likely not exhaustive.
> 
> 1. Bring numactl into oe-core
> 2. move rt-tests out of oe-core
> 3. TMy to patch out the numa requirement and carry it forever(doesn't appear to 
> be a small task)

I'd probably lean to 1, we do need to figure out the situation on arm
support though...

Cheers,

Richard

Re: [OE-core] RFC: Upgrading rt-tests requires numactl

[Ross Burton]

On Wed, 23 Sep 2020 at 18:23, Randy Witt <randy.e.witt@linux.intel.com> wrote:
> Another issue is that ARM is removed from COMPATIBLE_HOST in
> http://cgit.openembedded.org/meta-openembedded/tree/meta-oe/recipes-support/numactl/numactl_git.bb?h=master#n27.
> This may be for legacy reasons, but libnuma can be installed on most
> distributions running on an ARM host. Regardless, it would need to be changed to
> allow for rt-tests on ARM.

Yeah, that's probably very old.

$ lscpu
Architecture:                    aarch64
CPU op-mode(s):                  64-bit
Byte Order:                      Little Endian
CPU(s):                          256
On-line CPU(s) list:             0-255
Thread(s) per core:              4
Core(s) per socket:              32
Socket(s):                       2
NUMA node(s):                    2

The recipe has done that since it was added, so I'd call this
historical and just delete it.

Ross

Re: [OE-core] RFC: Upgrading rt-tests requires numactl

[Khem Raj]

On Wed, Sep 23, 2020 at 2:40 PM Ross Burton <ross@burtonini.com> wrote:
>
> On Wed, 23 Sep 2020 at 18:23, Randy Witt <randy.e.witt@linux.intel.com> wrote:
> > Another issue is that ARM is removed from COMPATIBLE_HOST in
> > http://cgit.openembedded.org/meta-openembedded/tree/meta-oe/recipes-support/numactl/numactl_git.bb?h=master#n27.
> > This may be for legacy reasons, but libnuma can be installed on most
> > distributions running on an ARM host. Regardless, it would need to be changed to
> > allow for rt-tests on ARM.
>
> Yeah, that's probably very old.
>
> $ lscpu
> Architecture:                    aarch64
> CPU op-mode(s):                  64-bit
> Byte Order:                      Little Endian
> CPU(s):                          256
> On-line CPU(s) list:             0-255
> Thread(s) per core:              4
> Core(s) per socket:              32
> Socket(s):                       2
> NUMA node(s):                    2
>
> The recipe has done that since it was added, so I'd call this
> historical and just delete it.

question is not aarch64 but arm (32bit) and I think answer is still no for arm.

>
> Ross
>
> 
>

Re: [OE-core] RFC: Upgrading rt-tests requires numactl

[Randy Witt]

On 9/23/20 11:00 PM, Khem Raj wrote:
> On Wed, Sep 23, 2020 at 2:40 PM Ross Burton <ross@burtonini.com> wrote:
>>
>> On Wed, 23 Sep 2020 at 18:23, Randy Witt <randy.e.witt@linux.intel.com> wrote:
>>> Another issue is that ARM is removed from COMPATIBLE_HOST in
>>> http://cgit.openembedded.org/meta-openembedded/tree/meta-oe/recipes-support/numactl/numactl_git.bb?h=master#n27.
>>> This may be for legacy reasons, but libnuma can be installed on most
>>> distributions running on an ARM host. Regardless, it would need to be changed to
>>> allow for rt-tests on ARM.
>>
>> Yeah, that's probably very old.
>>
>> $ lscpu
>> Architecture:                    aarch64
>> CPU op-mode(s):                  64-bit
>> Byte Order:                      Little Endian
>> CPU(s):                          256
>> On-line CPU(s) list:             0-255
>> Thread(s) per core:              4
>> Core(s) per socket:              32
>> Socket(s):                       2
>> NUMA node(s):                    2
>>
>> The recipe has done that since it was added, so I'd call this
>> historical and just delete it.
> 
> question is not aarch64 but arm (32bit) and I think answer is still no for arm.
> 

I compiled numactl on arm, and v1.8 of rt-tests. While the ptests for numactl 
fail, due to there being no actual numa support, the libraries and headers still 
work.

cyclictest from rt-tests seems to still set affinity appropriately and work. 
Should we make the ptests aware of the expected results when numa isn't 
supported? For example:

      root@qemuarm:/# /usr/lib/numactl/ptest/test/distance
      no numa support in kernel

I also tried v1.9 of rt-tests, but it fails due to the following 
https://git.kernel.org/pub/scm/utils/rt-tests/rt-tests.git/tree/src/oslat/oslat.c?h=v1.9#n72. 
I'm going to email the maintainer about that, since there is no way to disable 
any of the tests, outside of manually specifying each one. And it will break any 
architecture that isn't x86_64, i386, or PPC64.

>> Ross
>>
>> 
>>