From: Hideyuki Yamashita <yamashita.hideyuki@ntt-tx.co.jp>
To: Yasufumi Ogawa <yasufum.o@gmail.com>
Cc: x-fn-spp-ml@ntt-tx.co.jp, spp@dpdk.org
Subject: Re: [spp] (x-fn-spp-ml 796) Re: (x-fn-spp-ml 783) Re: [PATCH 5/5] docs: add note regarding NUMA configuration
Date: Thu, 18 Jun 2020 12:14:52 +0900 [thread overview]
Message-ID: <20200618121452.B90B.17218CA3@ntt-tx.co.jp_1> (raw)
In-Reply-To: <2de0e4ca-1452-8370-53c1-b9dbefc948b7@gmail.com>
Hello,
Thanks for your comments.
Please see inline.
> > Hi.
> > Sorry for delayed response.
> > Please see my comments inline.
> >
> >>> From: Hideyuki Yamashita <yamashita.hideyuki@ntt-tx.co.jp>
> >>>
> >>> This patch adds new notes for NUMA configuration when starting
> >>> spp_primary.
> >>>
> >>> This is pointed out by the following DPDK Bugzilla tickets.
> >>> https://bugs.dpdk.org/show_bug.cgi?id=457
> >>>
> >>> Signed-off-by: Hideyuki Yamashita <yamashita.hideyuki@ntt-tx.co.jp>
> >>> Signed-off-by: Naoki Takada <ntakada14@gmail.com>
> >>> ---
> >>> docs/guides/gsg/howto_use.rst | 12 ++++++++++++
> >>> 1 file changed, 12 insertions(+)
> >>>
> >>> diff --git a/docs/guides/gsg/howto_use.rst b/docs/guides/gsg/howto_use.rst
> >>> index f182198..4f2e6cd 100644
> >>> --- a/docs/guides/gsg/howto_use.rst
> >>> +++ b/docs/guides/gsg/howto_use.rst
> >>> @@ -422,6 +422,18 @@ if you run the process on single NUMA node.
> >>> If you use DPDK v18.11 or later, ``--base-virtaddr 0x100000000`` is enabled
> >>> in default. You need to use this option only for changing the default value.
> >>> > +.. note::
> >>> +
> >>> + ``spp_primary`` tries to create memory pool in the same NUMA node where
> >>> + it is launched. Under NUMA configuration, the NUMA node where ``spp_primary``
> >>> + is launched and the NUMA node where NIC is connected can be different
> >>> + (e.g. spp_primary runs in NUMA node 0 while NIC is connected with NUMA
> >>> + node 1).
> >>> + Such configuration may cause performance degradation. In general, under
> >>> + NUMA configuration, it is best practice to use CPU and NIC which belongs
> >>> + to the same NUMA node for best performance. So user should align those
> >>> + when performance degradation makes the situation critical.
> >>> +
> >> I have two comments.
> >>
> >> 1. Could I confirm WHAT should be configured for avoiding such a performance loss?
> >
> > NUMA node
> > - primary process will run (that can be specified with -l parameter)
> > - NIC belongs
> > should be the same to avoid performance loss.
> >
> > In general, topology regarding with NUMA node
> > (e.g. CPU core, NIC which is connected with specific NUMA node)
> > can be found in lstopo command.
> I would like to make it clear as an instruction for users. From my understanding, users should confirm that
> - Understand layout of hardware architecture of NICs and CPUs.
> - Assign lcores while launching spp_primary by considering the layout identified before.
>
> I understand your update for explanation is collect, but not so clear the purpose as instruction.
>I think it could be more agreeable if you start to explaining WHAT can
>be happened if you do not care about the layout (performance
>degradation actually), then HOW you get the layout by using `lstopo`
>and HOW you configure lcores by using `-l` option.
OK.
I think in general we can agree on the concept of the change.
I think it might be better that
- I add description in the "Performance Optimization" section because it
is highly related with "Performance"!
- Firstly I should explain "what will happen" if such consideration
is NOT taken into account by users
- Secondary I should describe "how" users can avoid such
performance degradations (e.g. use lstopo command, specify appropriate
lcore when starting up spp_primary process)
Anyway I think it is better to discuss above over "actual" changes.
Thanks
I will send revised version of the patch when it got available.
BR,
Hideyuki Yamashita
> Thanks,
> Yasufumi
>
> >
> >
> >> 2. It seems something abruptly considering context of this section because you start talking about performance suddenly.
> >> If it must be considered as a mandatory configuration and should be explained this section, I agree your update.
> >> On the other hand, what do you think to move this note to the next "Performance Optimization" section.
> >> I think no need to be a note if you move it to the next secion.
> >
> > I agree with your idea.
> > I think it is NOT mandatory, thus should be moved to next section
> > 'without' note.
> >
> >>
> >> Thanks
> >>
> >>> If ``spp_primary`` is launched with two or more lcores, forwarder or monitor
> >>> is activated. The default is forwarder and monitor is optional in this case.
> >>> If you use monitor thread, additional option ``--disp-stat`` is required.
> >
> >
next prev parent reply other threads:[~2020-06-18 3:16 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-05 0:28 [spp] [PATCH 0/5] updates for catching up DPDK20.02 x-fn-spp-ml
2020-06-05 0:28 ` [spp] [PATCH 1/5] docs: remove unnecessary usage of ethtool x-fn-spp-ml
2020-06-05 0:28 ` [spp] [PATCH 2/5] docs: resolve broken reference link x-fn-spp-ml
2020-06-05 0:28 ` [spp] [PATCH 3/5] docs: catch up updates in dpdk-20.02 x-fn-spp-ml
2020-06-08 8:02 ` Yasufumi Ogawa
2020-06-16 8:28 ` [spp] (x-fn-spp-ml 781) " Hideyuki Yamashita
2020-06-05 0:28 ` [spp] [PATCH 4/5] makefile: change default build target x-fn-spp-ml
2020-06-05 0:28 ` [spp] [PATCH 5/5] docs: add note regarding NUMA configuration x-fn-spp-ml
2020-06-08 8:21 ` Yasufumi Ogawa
2020-06-16 8:30 ` [spp] (x-fn-spp-ml 783) " Hideyuki Yamashita
2020-06-16 16:18 ` Yasufumi Ogawa
2020-06-18 3:14 ` Hideyuki Yamashita [this message]
2020-06-05 2:40 ` [spp] [PATCH 0/5] updates for catching up DPDK20.02 Itsuro ODA
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200618121452.B90B.17218CA3@ntt-tx.co.jp_1 \
--to=yamashita.hideyuki@ntt-tx.co.jp \
--cc=spp@dpdk.org \
--cc=x-fn-spp-ml@ntt-tx.co.jp \
--cc=yasufum.o@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).