From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from dpdk.org (dpdk.org [92.243.14.124])
	by inbox.dpdk.org (Postfix) with ESMTP id C3E6FA04B5;
	Tue, 27 Oct 2020 12:20:56 +0100 (CET)
Received: from [92.243.14.124] (localhost [127.0.0.1])
	by dpdk.org (Postfix) with ESMTP id DEBC02BDB;
	Tue, 27 Oct 2020 12:20:54 +0100 (CET)
Received: from mga14.intel.com (mga14.intel.com [192.55.52.115])
 by dpdk.org (Postfix) with ESMTP id 95A882BD5
 for <dev@dpdk.org>; Tue, 27 Oct 2020 12:20:52 +0100 (CET)
IronPort-SDR: a0kgFJZ5TfLEOK+4qpkR84H5imZ4rnpnKwMDMoX+WryLtpkIJ2FHr9MId7ALWjttvOtAZNpClg
 VSCaqjT4UlPw==
X-IronPort-AV: E=McAfee;i="6000,8403,9786"; a="167280958"
X-IronPort-AV: E=Sophos;i="5.77,423,1596524400"; d="scan'208";a="167280958"
X-Amp-Result: SKIPPED(no attachment in message)
X-Amp-File-Uploaded: False
Received: from orsmga005.jf.intel.com ([10.7.209.41])
 by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384;
 27 Oct 2020 04:20:50 -0700
IronPort-SDR: FdkDfE6wqhe2/S59Bd6JCyheSHFi1BGbl4brKOTXizpHzQgcza74XiQLpwj+HJ1jBfHMHwi12A
 9hqpBp3whycg==
X-IronPort-AV: E=Sophos;i="5.77,423,1596524400"; d="scan'208";a="535750840"
Received: from bricha3-mobl.ger.corp.intel.com ([10.214.252.158])
 by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-SHA;
 27 Oct 2020 04:20:46 -0700
Date: Tue, 27 Oct 2020 11:20:41 +0000
From: Bruce Richardson <bruce.richardson@intel.com>
To: Juraj =?utf-8?Q?Linke=C5=A1?= <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
Message-ID: <20201027112041.GD936@bricha3-MOBL.ger.corp.intel.com>
References: <1603280261-20206-1-git-send-email-juraj.linkes@pantheon.tech>
 <1603464488-25493-1-git-send-email-juraj.linkes@pantheon.tech>
 <1603464488-25493-4-git-send-email-juraj.linkes@pantheon.tech>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <1603464488-25493-4-git-send-email-juraj.linkes@pantheon.tech>
Subject: Re: [dpdk-dev] [PATCH v4 3/6] build: optional NUMA and cpu counts
	detection
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On Fri, Oct 23, 2020 at 04:48:05PM +0200, Juraj Linkeš wrote:
> Add an option to automatically discover the host's numa and cpu counts
> and use those values for a non cross-build.
> Give users the option to override the per-arch default values or values
> from cross files by specifying them on the command line with -Dmax_lcores
> and -Dmax_numa_nodes.
> 
> Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> ---
>  buildtools/get_cpu_count.py  |  7 ++++++
>  buildtools/get_numa_count.py | 22 +++++++++++++++++
>  buildtools/meson.build       |  2 ++
>  config/meson.build           | 48 ++++++++++++++++++++++++++++++++++--
>  meson_options.txt            |  8 +++---
>  5 files changed, 81 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..f0c49973a
> --- /dev/null
> +++ b/buildtools/get_numa_count.py
> @@ -0,0 +1,22 @@
> +#!/usr/bin/python3
> +# SPDX-License-Identifier: BSD-3-Clause
> +# Copyright (c) 2020 PANTHEON.tech s.r.o.
> +
> +import ctypes
> +import glob
> +import os
> +import subprocess
> +
> +if os.name == 'posix':
> +    if os.path.isdir('/sys/devices/system/node'):
> +        print(len(glob.glob('/sys/devices/system/node/node*')))
> +    else:
> +        print(subprocess.run(['sysctl', 'vm.ndomains'], capture_output=True).stdout)

I think you can shorten this, by just calling subprocess.run and not
capturing anything, in which case the stdout will be printed as normal.

	subprocess.run(['sysctl', 'vm.ndomains'])

> +
> +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 918ca2dfb..5c6fdcc7d 100644
> --- a/config/meson.build
> +++ b/config/meson.build
> @@ -230,8 +230,14 @@ 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'))
> +if not meson.is_cross_build()
> +	# set default values
> +	# these defaults may be overwritten by meson.build in an arch subdir
> +	# or later overwritten if a user specifies a value on the command line
> +	# or the user chooses to use values discovered from the build machine
> +	dpdk_conf.set('RTE_MAX_LCORE', 128)
> +	dpdk_conf.set('RTE_MAX_NUMA_NODES', 4)
> +endif

I think it might be better to remove this block, and instead set the values
below where you do the additional checks. It's confusing having these
settings managed in multiple places.

>  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'))
> @@ -250,6 +256,44 @@ compile_time_cpuflags = []
>  subdir(arch_subdir)
>  dpdk_conf.set('RTE_COMPILE_TIME_CPUFLAGS', ','.join(compile_time_cpuflags))
>  
> +max_lcores = get_option('max_lcores')
> +max_numa_nodes = get_option('max_numa_nodes')
> +if max_lcores > 0
> +	dpdk_conf.set('RTE_MAX_LCORE', max_lcores)
> +elif max_lcores == -1
> +	if not meson.is_cross_build()
> +		max_lcores = run_command(get_cpu_count_cmd).stdout().to_int()
> +		min_lcores = 2
> +		if max_lcores < min_lcores
> +			message('Found less than @0@ cores, building for @0@ cores'.format(min_lcores))
> +			max_lcores = min_lcores
> +		else
> +			message('Found @0@ cores'.format(max_lcores))
> +		endif
> +		dpdk_conf.set('RTE_MAX_LCORE', max_lcores)
> +	endif
> +endif
> +
> +if max_numa_nodes > 0
> +	dpdk_conf.set('RTE_MAX_NUMA_NODES', max_numa_nodes)
> +elif max_numa_nodes == -1
> +	if not meson.is_cross_build()
> +		max_numa_nodes = run_command(get_numa_count_cmd).stdout().to_int()
> +		message('Found @0@ numa nodes'.format(max_numa_nodes))
> +		dpdk_conf.set('RTE_MAX_NUMA_NODES', max_numa_nodes)
> +	endif
> +endif
> +
> +# check that cpu and numa count is set in cross builds
> +if meson.is_cross_build()
> +	if not dpdk_conf.has('RTE_MAX_LCORE')
> +		error('Number of cores for cross build not specified in @0@ subdir (e.g. in a cross-file) nor on the cmdline'.format(arch_subdir))
> +	endif
> +	if not dpdk_conf.has('RTE_MAX_NUMA_NODES')
> +		error('Number of numa nodes for cross build not specified in @0@ subdir (e.g. in a cross-file) nor on the cmdline'.format(arch_subdir))
> +	endif
> +endif
> +

I think we need some comments explaining all the logic here, and probably
some documentation updates.

>  # set the install path for the drivers
>  dpdk_conf.set_quoted('RTE_EAL_PMD_PATH', eal_pmd_path)
>  
> diff --git a/meson_options.txt b/meson_options.txt
> index 9bf18ab6b..a78c21b0d 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. Set to positive integer to overwrite per-arch or cross-compilation defaults. Set to -1 to use number of cores on the build machine.')
> +option('max_numa_nodes', type: 'integer', value: 0,
> +	description: 'maximum number of NUMA nodes supported by EAL. Set to positive integer to overwrite per-arch or cross-compilation defaults. Set to -1 to use number of numa nodes on the build machine.')
>  option('enable_trace_fp', type: 'boolean', value: false,
>  	description: 'enable fast path trace points.')
>  option('tests', type: 'boolean', value: true,
> -- 
> 2.20.1
>