[RFC,v2,3/6] build: automatic NUMA and cpu counts detection

  The build machine's number of cpus and numa nodes vary, resulting in
mismatched counts of RTE_MAX_LCORE and RTE_MAX_NUMA_NODES for many
builds. Automatically discover the host's numa and cpu counts to remove
this mismatch for native builds. Use current defaults for cross builds.
Leave users the option to override both if the specify a non-zero
amount on the command line.

Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
---
 buildtools/get_cpu_count.py  |  7 +++++++
 buildtools/get_numa_count.py | 17 +++++++++++++++++
 buildtools/meson.build       |  2 ++
 config/meson.build           | 20 ++++++++++++++++++--
 meson_options.txt            |  8 ++++----
 5 files changed, 48 insertions(+), 6 deletions(-)
 create mode 100644 buildtools/get_cpu_count.py
 create mode 100644 buildtools/get_numa_count.py
  

On Tue, Oct 13, 2020 at 04:54:39PM +0200, Juraj Linkeš wrote:
> The build machine's number of cpus and numa nodes vary, resulting in
> mismatched counts of RTE_MAX_LCORE and RTE_MAX_NUMA_NODES for many
> builds. Automatically discover the host's numa and cpu counts to remove
> this mismatch for native builds. Use current defaults for cross builds.
> Leave users the option to override both if the specify a non-zero
> amount on the command line.
> 
> Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> ---
>  buildtools/get_cpu_count.py  |  7 +++++++
>  buildtools/get_numa_count.py | 17 +++++++++++++++++
>  buildtools/meson.build       |  2 ++
>  config/meson.build           | 20 ++++++++++++++++++--
>  meson_options.txt            |  8 ++++----
>  5 files changed, 48 insertions(+), 6 deletions(-)
>  create mode 100644 buildtools/get_cpu_count.py
>  create mode 100644 buildtools/get_numa_count.py
> 
> diff --git a/buildtools/get_cpu_count.py b/buildtools/get_cpu_count.py
> new file mode 100644
> index 000000000..386f85f8b
> --- /dev/null
> +++ b/buildtools/get_cpu_count.py
> @@ -0,0 +1,7 @@
> +#!/usr/bin/python3
> +# SPDX-License-Identifier: BSD-3-Clause
> +# Copyright (c) 2020 PANTHEON.tech s.r.o.
> +
> +import os
> +
> +print(os.cpu_count())
> diff --git a/buildtools/get_numa_count.py b/buildtools/get_numa_count.py
> new file mode 100644
> index 000000000..f2ad35532
> --- /dev/null
> +++ b/buildtools/get_numa_count.py
> @@ -0,0 +1,17 @@
> +#!/usr/bin/python3
> +# SPDX-License-Identifier: BSD-3-Clause
> +# Copyright (c) 2020 PANTHEON.tech s.r.o.
> +
> +import ctypes
> +import glob
> +import os
> +
> +if os.name == 'posix':
> +    print(len(glob.glob('/sys/devices/system/node/node*')))

FreeBSD also reports it's os.name as posix, but doesn't have a /sys/devices
path to query.

> +elif os.name == 'nt':
> +    libkernel32 = ctypes.windll.kernel32
> +
> +    count = ctypes.c_ulong()
> +
> +    libkernel32.GetNumaHighestNodeNumber(ctypes.pointer(count))
> +    print(count.value + 1)
> diff --git a/buildtools/meson.build b/buildtools/meson.build
> index 04808dabc..925e733b1 100644
> --- a/buildtools/meson.build
> +++ b/buildtools/meson.build
> @@ -17,3 +17,5 @@ else
>  endif
>  map_to_win_cmd = py3 + files('map_to_win.py')
>  sphinx_wrapper = py3 + files('call-sphinx-build.py')
> +get_cpu_count_cmd = py3 + files('get_cpu_count.py')
> +get_numa_count_cmd = py3 + files('get_numa_count.py')
> diff --git a/config/meson.build b/config/meson.build
> index 4bd65d98e..84c31c8e7 100644
> --- a/config/meson.build
> +++ b/config/meson.build
> @@ -226,8 +226,24 @@ foreach arg: warning_flags
>  endforeach
>  
>  # set other values pulled from the build options
> -dpdk_conf.set('RTE_MAX_LCORE', get_option('max_lcores'))
> -dpdk_conf.set('RTE_MAX_NUMA_NODES', get_option('max_numa_nodes'))
> +max_lcores = get_option('max_lcores')
> +if max_lcores == 0
> +	if meson.is_cross_build()
> +		max_lcores = 4

This seems a rather low number to default to. I would suspect in this case
you might be better just to error out, i.e. require that the max_lcores
value is given when cross-compiling.

> +	else
> +		max_lcores = run_command(get_cpu_count_cmd).stdout()
> +	endif
> +endif
> +dpdk_conf.set('RTE_MAX_LCORE', max_lcores)
> +max_numa_nodes = get_option('max_numa_nodes')
> +if max_numa_nodes == 0
> +	if meson.is_cross_build()
> +		max_numa_nodes = 128

Same here, I think it's better to force the user to specify a value.
BTW: did you unintentionally switch the max cores and max numa nodes values
in this patch?

> +	else
> +		max_numa_nodes = run_command(get_numa_count_cmd).stdout()
> +	endif
> +endif
> +dpdk_conf.set('RTE_MAX_NUMA_NODES', max_numa_nodes)
>  dpdk_conf.set('RTE_MAX_ETHPORTS', get_option('max_ethports'))
>  dpdk_conf.set('RTE_LIBEAL_USE_HPET', get_option('use_hpet'))
>  dpdk_conf.set('RTE_ENABLE_TRACE_FP', get_option('enable_trace_fp'))
> diff --git a/meson_options.txt b/meson_options.txt
> index 9bf18ab6b..60a949fca 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -26,10 +26,10 @@ option('machine', type: 'string', value: 'native',
>  	description: 'set the target machine type')
>  option('max_ethports', type: 'integer', value: 32,
>  	description: 'maximum number of Ethernet devices')
> -option('max_lcores', type: 'integer', value: 128,
> -	description: 'maximum number of cores/threads supported by EAL')
> -option('max_numa_nodes', type: 'integer', value: 4,
> -	description: 'maximum number of NUMA nodes supported by EAL')
> +option('max_lcores', type: 'integer', value: 0,
> +	description: 'maximum number of cores/threads supported by EAL. Value 0 means the number of cpus on the host will be used')
> +option('max_numa_nodes', type: 'integer', value: 0,
> +	description: 'maximum number of NUMA nodes supported by EAL. Value 0 means the number of numa nodes on the host will be used')
>  option('enable_trace_fp', type: 'boolean', value: false,
>  	description: 'enable fast path trace points.')
>  option('tests', type: 'boolean', value: true,
> -- 
> 2.20.1
>
  

> -----Original Message-----
> From: Bruce Richardson <bruce.richardson@intel.com>
> Sent: Tuesday, October 13, 2020 5:48 PM
> To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> Cc: Ruifeng.Wang@arm.com; Honnappa.Nagarahalli@arm.com;
> Phil.Yang@arm.com; vcchunga@amazon.com; Dharmik.Thakkar@arm.com;
> jerinjacobk@gmail.com; hemant.agrawal@nxp.com; dev@dpdk.org
> Subject: Re: [RFC PATCH v2 3/6] build: automatic NUMA and cpu counts
> detection
> 
> On Tue, Oct 13, 2020 at 04:54:39PM +0200, Juraj Linkeš wrote:
> > The build machine's number of cpus and numa nodes vary, resulting in
> > mismatched counts of RTE_MAX_LCORE and RTE_MAX_NUMA_NODES for
> many
> > builds. Automatically discover the host's numa and cpu counts to
> > remove this mismatch for native builds. Use current defaults for cross builds.
> > Leave users the option to override both if the specify a non-zero
> > amount on the command line.
> >
> > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > ---
> >  buildtools/get_cpu_count.py  |  7 +++++++
> > buildtools/get_numa_count.py | 17 +++++++++++++++++
> >  buildtools/meson.build       |  2 ++
> >  config/meson.build           | 20 ++++++++++++++++++--
> >  meson_options.txt            |  8 ++++----
> >  5 files changed, 48 insertions(+), 6 deletions(-)  create mode 100644
> > buildtools/get_cpu_count.py  create mode 100644
> > buildtools/get_numa_count.py
> >
> > diff --git a/buildtools/get_cpu_count.py b/buildtools/get_cpu_count.py
> > new file mode 100644 index 000000000..386f85f8b
> > --- /dev/null
> > +++ b/buildtools/get_cpu_count.py
> > @@ -0,0 +1,7 @@
> > +#!/usr/bin/python3
> > +# SPDX-License-Identifier: BSD-3-Clause # Copyright (c) 2020
> > +PANTHEON.tech s.r.o.
> > +
> > +import os
> > +
> > +print(os.cpu_count())
> > diff --git a/buildtools/get_numa_count.py
> > b/buildtools/get_numa_count.py new file mode 100644 index
> > 000000000..f2ad35532
> > --- /dev/null
> > +++ b/buildtools/get_numa_count.py
> > @@ -0,0 +1,17 @@
> > +#!/usr/bin/python3
> > +# SPDX-License-Identifier: BSD-3-Clause # Copyright (c) 2020
> > +PANTHEON.tech s.r.o.
> > +
> > +import ctypes
> > +import glob
> > +import os
> > +
> > +if os.name == 'posix':
> > +    print(len(glob.glob('/sys/devices/system/node/node*')))
> 
> FreeBSD also reports it's os.name as posix, but doesn't have a /sys/devices path
> to query.
> 

Do you know how do I get numa count on FreeBDS? I don't want to use the numa library if we can to avoid unneccesary dependencies. Do we need to cover some other cases other than FreeBDS, other Linux and Windows?

> > +elif os.name == 'nt':
> > +    libkernel32 = ctypes.windll.kernel32
> > +
> > +    count = ctypes.c_ulong()
> > +
> > +    libkernel32.GetNumaHighestNodeNumber(ctypes.pointer(count))
> > +    print(count.value + 1)
> > diff --git a/buildtools/meson.build b/buildtools/meson.build index
> > 04808dabc..925e733b1 100644
> > --- a/buildtools/meson.build
> > +++ b/buildtools/meson.build
> > @@ -17,3 +17,5 @@ else
> >  endif
> >  map_to_win_cmd = py3 + files('map_to_win.py')  sphinx_wrapper = py3 +
> > files('call-sphinx-build.py')
> > +get_cpu_count_cmd = py3 + files('get_cpu_count.py')
> > +get_numa_count_cmd = py3 + files('get_numa_count.py')
> > diff --git a/config/meson.build b/config/meson.build index
> > 4bd65d98e..84c31c8e7 100644
> > --- a/config/meson.build
> > +++ b/config/meson.build
> > @@ -226,8 +226,24 @@ foreach arg: warning_flags  endforeach
> >
> >  # set other values pulled from the build options
> > -dpdk_conf.set('RTE_MAX_LCORE', get_option('max_lcores'))
> > -dpdk_conf.set('RTE_MAX_NUMA_NODES', get_option('max_numa_nodes'))
> > +max_lcores = get_option('max_lcores') if max_lcores == 0
> > +	if meson.is_cross_build()
> > +		max_lcores = 4
> 
> This seems a rather low number to default to. I would suspect in this case you
> might be better just to error out, i.e. require that the max_lcores value is given
> when cross-compiling.
> 
> > +	else
> > +		max_lcores = run_command(get_cpu_count_cmd).stdout()
> > +	endif
> > +endif
> > +dpdk_conf.set('RTE_MAX_LCORE', max_lcores) max_numa_nodes =
> > +get_option('max_numa_nodes') if max_numa_nodes == 0
> > +	if meson.is_cross_build()
> > +		max_numa_nodes = 128
> 
> Same here, I think it's better to force the user to specify a value.
> BTW: did you unintentionally switch the max cores and max numa nodes values
> in this patch?
> 

Yes, the values are switched. Forcing the user to specify these might be tricky - we want to specify cpu and numa counts in cross files and this check happens before the values from cross files are used (in another patch I'm asking about having defaults in config/arm/meson.build and if we don't have defaults we won't want them there as well. The remaning question would be what get priority - command line options or cross file options. I'm leaning towards command line options). I'll think about switching the order.

> > +	else
> > +		max_numa_nodes =
> run_command(get_numa_count_cmd).stdout()
> > +	endif
> > +endif
> > +dpdk_conf.set('RTE_MAX_NUMA_NODES', max_numa_nodes)
> >  dpdk_conf.set('RTE_MAX_ETHPORTS', get_option('max_ethports'))
> > dpdk_conf.set('RTE_LIBEAL_USE_HPET', get_option('use_hpet'))
> > dpdk_conf.set('RTE_ENABLE_TRACE_FP', get_option('enable_trace_fp'))
> > diff --git a/meson_options.txt b/meson_options.txt index
> > 9bf18ab6b..60a949fca 100644
> > --- a/meson_options.txt
> > +++ b/meson_options.txt
> > @@ -26,10 +26,10 @@ option('machine', type: 'string', value: 'native',
> >  	description: 'set the target machine type')  option('max_ethports',
> > type: 'integer', value: 32,
> >  	description: 'maximum number of Ethernet devices')
> > -option('max_lcores', type: 'integer', value: 128,
> > -	description: 'maximum number of cores/threads supported by EAL')
> > -option('max_numa_nodes', type: 'integer', value: 4,
> > -	description: 'maximum number of NUMA nodes supported by EAL')
> > +option('max_lcores', type: 'integer', value: 0,
> > +	description: 'maximum number of cores/threads supported by EAL.
> > +Value 0 means the number of cpus on the host will be used')
> option('max_numa_nodes', type: 'integer', value: 0,
> > +	description: 'maximum number of NUMA nodes supported by EAL. Value
> 0
> > +means the number of numa nodes on the host will be used')
> >  option('enable_trace_fp', type: 'boolean', value: false,
> >  	description: 'enable fast path trace points.')  option('tests',
> > type: 'boolean', value: true,
> > --
> > 2.20.1
> >
  

On Wed, Oct 14, 2020 at 06:04:52AM +0000, Juraj Linkeš wrote:
> 
> 
> > -----Original Message-----
> > From: Bruce Richardson <bruce.richardson@intel.com>
> > Sent: Tuesday, October 13, 2020 5:48 PM
> > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > Cc: Ruifeng.Wang@arm.com; Honnappa.Nagarahalli@arm.com;
> > Phil.Yang@arm.com; vcchunga@amazon.com; Dharmik.Thakkar@arm.com;
> > jerinjacobk@gmail.com; hemant.agrawal@nxp.com; dev@dpdk.org
> > Subject: Re: [RFC PATCH v2 3/6] build: automatic NUMA and cpu counts
> > detection
> > 
> > On Tue, Oct 13, 2020 at 04:54:39PM +0200, Juraj Linkeš wrote:
> > > The build machine's number of cpus and numa nodes vary, resulting in
> > > mismatched counts of RTE_MAX_LCORE and RTE_MAX_NUMA_NODES for
> > many
> > > builds. Automatically discover the host's numa and cpu counts to
> > > remove this mismatch for native builds. Use current defaults for cross builds.
> > > Leave users the option to override both if the specify a non-zero
> > > amount on the command line.
> > >
> > > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > ---
> > >  buildtools/get_cpu_count.py  |  7 +++++++
> > > buildtools/get_numa_count.py | 17 +++++++++++++++++
> > >  buildtools/meson.build       |  2 ++
> > >  config/meson.build           | 20 ++++++++++++++++++--
> > >  meson_options.txt            |  8 ++++----
> > >  5 files changed, 48 insertions(+), 6 deletions(-)  create mode 100644
> > > buildtools/get_cpu_count.py  create mode 100644
> > > buildtools/get_numa_count.py
> > >
> > > diff --git a/buildtools/get_cpu_count.py b/buildtools/get_cpu_count.py
> > > new file mode 100644 index 000000000..386f85f8b
> > > --- /dev/null
> > > +++ b/buildtools/get_cpu_count.py
> > > @@ -0,0 +1,7 @@
> > > +#!/usr/bin/python3
> > > +# SPDX-License-Identifier: BSD-3-Clause # Copyright (c) 2020
> > > +PANTHEON.tech s.r.o.
> > > +
> > > +import os
> > > +
> > > +print(os.cpu_count())
> > > diff --git a/buildtools/get_numa_count.py
> > > b/buildtools/get_numa_count.py new file mode 100644 index
> > > 000000000..f2ad35532
> > > --- /dev/null
> > > +++ b/buildtools/get_numa_count.py
> > > @@ -0,0 +1,17 @@
> > > +#!/usr/bin/python3
> > > +# SPDX-License-Identifier: BSD-3-Clause # Copyright (c) 2020
> > > +PANTHEON.tech s.r.o.
> > > +
> > > +import ctypes
> > > +import glob
> > > +import os
> > > +
> > > +if os.name == 'posix':
> > > +    print(len(glob.glob('/sys/devices/system/node/node*')))
> > 
> > FreeBSD also reports it's os.name as posix, but doesn't have a /sys/devices path
> > to query.
> > 
> 
> Do you know how do I get numa count on FreeBDS? I don't want to use the numa library if we can to avoid unneccesary dependencies. Do we need to cover some other cases other than FreeBDS, other Linux and Windows?
> 

To get numa count on freebsd, you can query it using "sysctl vm.ndomains"
command. However, the bigger issue here is that you need something
different other than os.name to distinguish between linux and freebsd.

Regards,
/Bruce
  

> -----Original Message-----
> From: Bruce Richardson <bruce.richardson@intel.com>
> Sent: Wednesday, October 14, 2020 10:16 AM
> To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> Cc: Ruifeng.Wang@arm.com; Honnappa.Nagarahalli@arm.com;
> Phil.Yang@arm.com; vcchunga@amazon.com; Dharmik.Thakkar@arm.com;
> jerinjacobk@gmail.com; hemant.agrawal@nxp.com; dev@dpdk.org
> Subject: Re: [RFC PATCH v2 3/6] build: automatic NUMA and cpu counts
> detection
> 
> On Wed, Oct 14, 2020 at 06:04:52AM +0000, Juraj Linkeš wrote:
> >
> >
> > > -----Original Message-----
> > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > Sent: Tuesday, October 13, 2020 5:48 PM
> > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > Cc: Ruifeng.Wang@arm.com; Honnappa.Nagarahalli@arm.com;
> > > Phil.Yang@arm.com; vcchunga@amazon.com; Dharmik.Thakkar@arm.com;
> > > jerinjacobk@gmail.com; hemant.agrawal@nxp.com; dev@dpdk.org
> > > Subject: Re: [RFC PATCH v2 3/6] build: automatic NUMA and cpu counts
> > > detection
> > >
> > > On Tue, Oct 13, 2020 at 04:54:39PM +0200, Juraj Linkeš wrote:
> > > > The build machine's number of cpus and numa nodes vary, resulting
> > > > in mismatched counts of RTE_MAX_LCORE and RTE_MAX_NUMA_NODES
> for
> > > many
> > > > builds. Automatically discover the host's numa and cpu counts to
> > > > remove this mismatch for native builds. Use current defaults for cross
> builds.
> > > > Leave users the option to override both if the specify a non-zero
> > > > amount on the command line.
> > > >
> > > > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > > ---
> > > >  buildtools/get_cpu_count.py  |  7 +++++++
> > > > buildtools/get_numa_count.py | 17 +++++++++++++++++
> > > >  buildtools/meson.build       |  2 ++
> > > >  config/meson.build           | 20 ++++++++++++++++++--
> > > >  meson_options.txt            |  8 ++++----
> > > >  5 files changed, 48 insertions(+), 6 deletions(-)  create mode
> > > > 100644 buildtools/get_cpu_count.py  create mode 100644
> > > > buildtools/get_numa_count.py
> > > >
> > > > diff --git a/buildtools/get_cpu_count.py
> > > > b/buildtools/get_cpu_count.py new file mode 100644 index
> > > > 000000000..386f85f8b
> > > > --- /dev/null
> > > > +++ b/buildtools/get_cpu_count.py
> > > > @@ -0,0 +1,7 @@
> > > > +#!/usr/bin/python3
> > > > +# SPDX-License-Identifier: BSD-3-Clause # Copyright (c) 2020
> > > > +PANTHEON.tech s.r.o.
> > > > +
> > > > +import os
> > > > +
> > > > +print(os.cpu_count())
> > > > diff --git a/buildtools/get_numa_count.py
> > > > b/buildtools/get_numa_count.py new file mode 100644 index
> > > > 000000000..f2ad35532
> > > > --- /dev/null
> > > > +++ b/buildtools/get_numa_count.py
> > > > @@ -0,0 +1,17 @@
> > > > +#!/usr/bin/python3
> > > > +# SPDX-License-Identifier: BSD-3-Clause # Copyright (c) 2020
> > > > +PANTHEON.tech s.r.o.
> > > > +
> > > > +import ctypes
> > > > +import glob
> > > > +import os
> > > > +
> > > > +if os.name == 'posix':
> > > > +    print(len(glob.glob('/sys/devices/system/node/node*')))
> > >
> > > FreeBSD also reports it's os.name as posix, but doesn't have a
> > > /sys/devices path to query.
> > >
> >
> > Do you know how do I get numa count on FreeBDS? I don't want to use the
> numa library if we can to avoid unneccesary dependencies. Do we need to cover
> some other cases other than FreeBDS, other Linux and Windows?
> >
> 
> To get numa count on freebsd, you can query it using "sysctl vm.ndomains"
> command. However, the bigger issue here is that you need something different
> other than os.name to distinguish between linux and freebsd.
> 

That should only be a matter of finding the right Python api - https://docs.python.org/3/library/sys.html?highlight=platform#sys.platform should be it.

> Regards,
> /Bruce
  

On Wed, Oct 14, 2020 at 08:52:12AM +0000, Juraj Linkeš wrote:
> 
> 
> > -----Original Message-----
> > From: Bruce Richardson <bruce.richardson@intel.com>
> > Sent: Wednesday, October 14, 2020 10:16 AM
> > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > Cc: Ruifeng.Wang@arm.com; Honnappa.Nagarahalli@arm.com;
> > Phil.Yang@arm.com; vcchunga@amazon.com; Dharmik.Thakkar@arm.com;
> > jerinjacobk@gmail.com; hemant.agrawal@nxp.com; dev@dpdk.org
> > Subject: Re: [RFC PATCH v2 3/6] build: automatic NUMA and cpu counts
> > detection
> > 
> > On Wed, Oct 14, 2020 at 06:04:52AM +0000, Juraj Linkeš wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > > Sent: Tuesday, October 13, 2020 5:48 PM
> > > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > > Cc: Ruifeng.Wang@arm.com; Honnappa.Nagarahalli@arm.com;
> > > > Phil.Yang@arm.com; vcchunga@amazon.com; Dharmik.Thakkar@arm.com;
> > > > jerinjacobk@gmail.com; hemant.agrawal@nxp.com; dev@dpdk.org
> > > > Subject: Re: [RFC PATCH v2 3/6] build: automatic NUMA and cpu counts
> > > > detection
> > > >
> > > > On Tue, Oct 13, 2020 at 04:54:39PM +0200, Juraj Linkeš wrote:
> > > > > The build machine's number of cpus and numa nodes vary, resulting
> > > > > in mismatched counts of RTE_MAX_LCORE and RTE_MAX_NUMA_NODES
> > for
> > > > many
> > > > > builds. Automatically discover the host's numa and cpu counts to
> > > > > remove this mismatch for native builds. Use current defaults for cross
> > builds.
> > > > > Leave users the option to override both if the specify a non-zero
> > > > > amount on the command line.
> > > > >
> > > > > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > > > ---
> > > > >  buildtools/get_cpu_count.py  |  7 +++++++
> > > > > buildtools/get_numa_count.py | 17 +++++++++++++++++
> > > > >  buildtools/meson.build       |  2 ++
> > > > >  config/meson.build           | 20 ++++++++++++++++++--
> > > > >  meson_options.txt            |  8 ++++----
> > > > >  5 files changed, 48 insertions(+), 6 deletions(-)  create mode
> > > > > 100644 buildtools/get_cpu_count.py  create mode 100644
> > > > > buildtools/get_numa_count.py
> > > > >
> > > > > diff --git a/buildtools/get_cpu_count.py
> > > > > b/buildtools/get_cpu_count.py new file mode 100644 index
> > > > > 000000000..386f85f8b
> > > > > --- /dev/null
> > > > > +++ b/buildtools/get_cpu_count.py
> > > > > @@ -0,0 +1,7 @@
> > > > > +#!/usr/bin/python3
> > > > > +# SPDX-License-Identifier: BSD-3-Clause # Copyright (c) 2020
> > > > > +PANTHEON.tech s.r.o.
> > > > > +
> > > > > +import os
> > > > > +
> > > > > +print(os.cpu_count())
> > > > > diff --git a/buildtools/get_numa_count.py
> > > > > b/buildtools/get_numa_count.py new file mode 100644 index
> > > > > 000000000..f2ad35532
> > > > > --- /dev/null
> > > > > +++ b/buildtools/get_numa_count.py
> > > > > @@ -0,0 +1,17 @@
> > > > > +#!/usr/bin/python3
> > > > > +# SPDX-License-Identifier: BSD-3-Clause # Copyright (c) 2020
> > > > > +PANTHEON.tech s.r.o.
> > > > > +
> > > > > +import ctypes
> > > > > +import glob
> > > > > +import os
> > > > > +
> > > > > +if os.name == 'posix':
> > > > > +    print(len(glob.glob('/sys/devices/system/node/node*')))
> > > >
> > > > FreeBSD also reports it's os.name as posix, but doesn't have a
> > > > /sys/devices path to query.
> > > >
> > >
> > > Do you know how do I get numa count on FreeBDS? I don't want to use the
> > numa library if we can to avoid unneccesary dependencies. Do we need to cover
> > some other cases other than FreeBDS, other Linux and Windows?
> > >
> > 
> > To get numa count on freebsd, you can query it using "sysctl vm.ndomains"
> > command. However, the bigger issue here is that you need something different
> > other than os.name to distinguish between linux and freebsd.
> > 
> 
> That should only be a matter of finding the right Python api - https://docs.python.org/3/library/sys.html?highlight=platform#sys.platform should be it.
>
Yep. Though thinking about it afterwards too, checking between bsd and
linux could also be as simple as using the /sys path if it exists, and
trying to use sysctl otherwise.

/Bruce