DPDK patches and discussions
 help / color / mirror / Atom feed
From: Stephen Hemminger <stephen@networkplumber.org>
To: Saber Rezvani <irsaber@zoho.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] IXGBE throughput loss with 4+ cores
Date: Tue, 28 Aug 2018 09:01:42 -0700	[thread overview]
Message-ID: <20180828090142.1262c5ea@shemminger-XPS-13-9360> (raw)
In-Reply-To: <74400e6a-91ba-3648-0980-47ceae1089a7@zoho.com>

On Tue, 28 Aug 2018 17:34:27 +0430
Saber Rezvani <irsaber@zoho.com> wrote:

> Hi,
> 
> 
> I have run multi_process/symmetric_mp example in DPDK example directory.
> For a one process its throughput is line rate but as I increase the
> number of cores I see decrease in throughput. For example, If the number
> of queues set to 4 and each queue assigns to a single core, then the
> throughput will be something about 9.4. if 8 queues, then throughput
> will be 8.5.
> 
> I have read the following, but it was not convincing.
> 
> http://mails.dpdk.org/archives/dev/2015-October/024960.html
> 
> 
> I am eagerly looking forward to hearing from you, all.
> 
> 
> Best wishes,
> 
> Saber
> 
> 

Not completely surprising. If you have more cores than packet line rate
then the number of packets returned for each call to rx_burst will be less.
With large number of cores, most of the time will be spent doing reads of
PCI registers for no packets!

  reply	other threads:[~2018-08-28 16:01 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-28 13:04 Saber Rezvani
2018-08-28 16:01 ` Stephen Hemminger [this message]
2018-08-28 17:05   ` Saber Rezvani
2018-08-28 19:09     ` Wiles, Keith
2018-08-28 19:16       ` Saber Rezvani
2018-08-28 21:09         ` Wiles, Keith
2018-08-29 17:19           ` Saber Rezvani
2018-08-29 18:52             ` Wiles, Keith
2018-08-30  4:08               ` Saber Rezvani
2018-09-06  6:10 Saber Rezvani
2018-09-06 17:48 ` Wiles, Keith

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=20180828090142.1262c5ea@shemminger-XPS-13-9360 \
    --to=stephen@networkplumber.org \
    --cc=dev@dpdk.org \
    --cc=irsaber@zoho.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).