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/ > >> -----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 >> >> >
