Hi Dharmik, > -----Original Message----- > From: Dharmik Thakkar <dharmik.thak...@arm.com> > Sent: Tuesday, October 13, 2020 5:15 PM > To: Juraj Linkeš <juraj.lin...@pantheon.tech> > Cc: tho...@monjalon.net; dev@dpdk.org; Stephen Hemminger > <step...@networkplumber.org>; Jerin Jacob <jerinjac...@gmail.com>; nd > <n...@arm.com> > Subject: Re: [dpdk-dev] [PATCH 2/2] build: find max lcore programmatically > > Hi Juraj, > > > On Oct 13, 2020, at 9:58 AM, Juraj Linkeš <juraj.lin...@pantheon.tech> > > wrote: > > > > I believe we're going to drop this patch series in favor of > http://patches.dpdk.org/project/dpdk/list/?series=12923. > > I can see you have included this feature in your series. Thank you! > What are your thoughts on the other patch [1]? Do you plan on including that > as > well in your series? > > [1] [1/2] config/arm: avoid variable reuse > https://patches.dpdk.org/patch/75946/ >
I believe the general idea of your patch is alredy part of my patch series in this patch: http://patches.dpdk.org/patch/80572/ > > > >> -----Original Message----- > >> From: Thomas Monjalon <tho...@monjalon.net> > >> Sent: Tuesday, October 13, 2020 4:32 PM > >> To: Dharmik Thakkar <dharmik.thak...@arm.com> > >> Cc: Juraj Linkeš <juraj.lin...@pantheon.tech>; dev@dpdk.org; Stephen > >> Hemminger <step...@networkplumber.org>; Jerin Jacob > >> <jerinjac...@gmail.com>; nd <n...@arm.com> > >> Subject: Re: [dpdk-dev] [PATCH 2/2] build: find max lcore > >> programmatically > >> > >> Please, what is the conclusion here? > >> > >> > >> 18/09/2020 07:47, Dharmik Thakkar: > >>> > >>>> On Sep 17, 2020, at 4:56 AM, Juraj Linkeš > >>>> <juraj.lin...@pantheon.tech> > >> wrote: > >>>> > >>>> > >>>> > >>>>> -----Original Message----- > >>>>> From: Dharmik Thakkar <dharmik.thak...@arm.com> > >>>>> Sent: Friday, September 4, 2020 7:44 AM > >>>>> To: Stephen Hemminger <step...@networkplumber.org> > >>>>> Cc: Juraj Linkeš <juraj.lin...@pantheon.tech>; Jerin Jacob > >>>>> <jerinjac...@gmail.com>; tho...@monjalon.net; dpdk-dev > >>>>> <dev@dpdk.org>; nd <n...@arm.com> > >>>>> Subject: Re: [dpdk-dev] [PATCH 2/2] build: find max lcore > >>>>> programmatically > >>>>> > >>>>> > >>>>> > >>>>>> On Sep 3, 2020, at 5:52 PM, Stephen Hemminger > >>>>> <step...@networkplumber.org> wrote: > >>>>>> > >>>>>> On Thu, 3 Sep 2020 06:20:17 +0000 Juraj Linkeš > >>>>>> <juraj.lin...@pantheon.tech> wrote: > >>>>>> > >>>>>>>> -----Original Message----- > >>>>>>>> From: dev <dev-boun...@dpdk.org> On Behalf Of Dharmik Thakkar > >>>>>>>> Sent: Wednesday, August 26, 2020 6:56 AM > >>>>>>>> To: Jerin Jacob <jerinjac...@gmail.com> > >>>>>>>> Cc: tho...@monjalon.net; dpdk-dev <dev@dpdk.org>; nd > >>>>>>>> <n...@arm.com> > >>>>>>>> Subject: Re: [dpdk-dev] [PATCH 2/2] build: find max lcore > >>>>>>>> programmatically > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>>> On Aug 25, 2020, at 11:47 PM, Jerin Jacob > >>>>>>>>> <jerinjac...@gmail.com> > >>>>> wrote: > >>>>>>>>> > >>>>>>>>> On Wed, Aug 26, 2020 at 2:44 AM Dharmik Thakkar > >>>>>>>> <dharmik.thak...@arm.com> wrote: > >>>>>>>>>> > >>>>>>>>>> For Arm, RTE_MAX_LCORE is hard-coded into the config. It > >>>>>>>>>> leads to incorrect RTE_MAX_LCORE when machines have same > >> Implemener > >>>>>>>>>> and part number but different number of CPUs. > >>>>>>>>>> For x86, RTE_MAX_LCORE is always set to 128 (using the value > >>>>>>>>>> set in > >>>>>>>>>> meson_options.txt) > >>>>>>>>>> > >>>>>>>>>> Use python script to find max lcore when using native build > >>>>>>>>>> to correctly set RTE_MAX_LCORE. > >>>>>>>>> > >>>>>>>>> We may need to build on the native arm64 machine and use it on > >>>>>>>>> another > >>>>>>>>> arm64 machine(Just like x86). > >>>>>>>>> So I think, at least for default config(which will be used by > >>>>>>>>> distribution) to support max > >>>>>>>>> lcores as fixed. I am not sure this patch changes those > >>>>>>>>> aspects or not? Please check. > >>>>>>>> > >>>>>>>> This patch does *not* affect ‘default’ build type and cross- > compilation. > >>>>>>>> > >>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> Signed-off-by: Dharmik Thakkar <dharmik.thak...@arm.com> > >>>>>>>>>> Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com> > >>>>>>>>>> --- > >>>>>>>>>> config/get_max_lcores.py | 13 +++++++++++++ > >>>>>>>>>> config/meson.build | 13 ++++++++++++- > >>>>>>>>>> 2 files changed, 25 insertions(+), 1 deletion(-) create mode > >>>>>>>>>> 100755 config/get_max_lcores.py > >>>>>>>>>> > >>>>>>>>>> diff --git a/config/get_max_lcores.py > >>>>>>>>>> b/config/get_max_lcores.py new file mode 100755 index > >>>>>>>>>> 000000000000..ebf1c7efdadd > >>>>>>>>>> --- /dev/null > >>>>>>>>>> +++ b/config/get_max_lcores.py > >>>>>>>>>> @@ -0,0 +1,13 @@ > >>>>>>>>>> +#!/usr/bin/python3 > >>>>>>>>>> +# SPDX-License-Identifier: BSD-3-Clause # Copyright(c) 2020 > >>>>>>>>>> +Arm Limited > >>>>>>>>>> + > >>>>>>>>>> +import os > >>>>>>>>>> + > >>>>>>>>>> +max_lcores = [] > >>>>>>>>>> + > >>>>>>>>>> +nCPU = os.cpu_count() > >>>>>>>>>> + > >>>>>>>>>> +max_lcores.append(str(nCPU & 0xFFF)) # Number of CPUs > >>>>>>>>>> + > >>>>>>>>>> +print(' '.join(max_lcores)) > >>>>>>>>>> diff --git a/config/meson.build b/config/meson.build index > >>>>>>>>>> 6996e5cbeaa5..80c05bc15d2f 100644 > >>>>>>>>>> --- a/config/meson.build > >>>>>>>>>> +++ b/config/meson.build > >>>>>>>>>> @@ -237,11 +237,22 @@ else # for 32-bit we need smaller > >>>>>>>>>> reserved memory > >>>>>>>> areas > >>>>>>>>>> dpdk_conf.set('RTE_MAX_MEM_MB', 2048) endif > >>>>>>>>>> > >>>>>>>>>> - > >>>>>>>>>> compile_time_cpuflags = [] > >>>>>>>>>> subdir(arch_subdir) > >>>>>>>>>> dpdk_conf.set('RTE_COMPILE_TIME_CPUFLAGS', > >>>>>>>>>> ','.join(compile_time_cpuflags)) > >>>>>>>>>> > >>>>>>>>>> +# set max lcores > >>>>>>>>>> +if machine != 'default' and not meson.is_cross_build() > >>>>>>>>>> + # The script returns max lcores > >>>>>>>>>> + params = files('get_max_lcores.py') > >>>>>>>>>> + cmd_out = run_command(params) > >>>>>>> > >>>>>>> Have you considered running just a shell command, such as "nproc -- > all"? > >>>>>> > >>>>>> Is this really a good idea? > >>>>>> For real distributions and NFV products, the build and runtime > >>>>>> environment will usually be different even if on same CPU architecture. > >>>>>> > >>>>>> In many cases there maybe a huge build machine (128 CPU) or in a > >>>>>> container (reported as single cpu) even if not doing cross build. > >>>>> > >>>>> That’s a great point, Stephen. IMO, this patch is useful when > >>>>> building and running natively. > >>>>> For all other purposes (like the ones you mentioned), do you think > >>>>> it is a good idea to set RTE_MAX_LCORE using -Dmax_lcores? > >>>> > >>>> We should only use this native builds, as that would be consistent > >>>> with the > >> current meson build philosophy of "meson figuring as much as possible > >> on its own". Any build other than native implies the user wants to > >> deviate from the build machine. > >>>> > >>> > >>> The MIDR value-based probing doesn’t quite work well for Arm IP > >>> (currently > >> being discussed on this patch: https://patches.dpdk.org/patch/76981/). > >>> > >>>> One way to do this automatic core count is when max_lcores=0 (0 > >>>> would > >> have the special meaning of "figure core count automatically"). We > >> can set that as default in meson_option.txt and then users will have > >> the ability to set it to whatever they want, even for native builds. What > >> do > you think? > >>>> > >>> > >>> Yes, agreed. > >>> > >>>> Currently the -Dmax_lcores option doesn't work for arm builds (the > >>>> value of > >> RTE_MAX_LCORE is overwritten in config/arm/meson.build). I believe > >> the patch tries to address this, but still, we need to be mindful of that. > >>>> > >>>> Juraj > >> > >> > >
