All of lore.kernel.org
 help / color / mirror / Atom feed
From: Bruce Richardson <bruce.richardson@intel.com>
To: Take Ceara <dumitru.ceara@gmail.com>
Cc: dev@dpdk.org
Subject: Re: Performance hit - NICs on different CPU sockets
Date: Mon, 13 Jun 2016 15:28:36 +0100	[thread overview]
Message-ID: <20160613142836.GH15736@bricha3-MOBL3> (raw)
In-Reply-To: <CAKKV4w-FYcK8XLv-HKUBJghNr-Fpsm-_EUqPSCb09zu2aZwxvQ@mail.gmail.com>

On Mon, Jun 13, 2016 at 04:07:37PM +0200, Take Ceara wrote:
> Hi,
> 
> I'm reposting here as I didn't get any answers on the dpdk-users mailing list.
> 
> We're working on a stateful traffic generator (www.warp17.net) using
> DPDK and we would like to control two XL710 NICs (one on each socket)
> to maximize CPU usage. It looks that we run into the following
> limitation:
> 
> http://dpdk.org/doc/guides/linux_gsg/nic_perf_intel_platform.html
> section 7.2, point 3
> 
> We completely split memory/cpu/NICs across the two sockets. However,
> the performance with a single CPU and both NICs on the same socket is
> better.
> Why do all the NICs have to be on the same socket, is there a
> driver/hw limitation?
> 
Hi,

so long as each thread only ever accesses the NIC on it's own local socket, then
there is no performance penalty. It's only when a thread on one socket works
using a NIC on a remote socket that you start seeing a penalty, with all
NIC-core communication having to go across QPI.

/Bruce

  reply	other threads:[~2016-06-13 14:28 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-13 14:07 Performance hit - NICs on different CPU sockets Take Ceara
2016-06-13 14:28 ` Bruce Richardson [this message]
2016-06-14  7:47   ` Take Ceara
2016-06-13 19:35 ` Wiles, Keith
2016-06-14  7:46   ` Take Ceara
2016-06-14 13:47     ` Wiles, Keith
2016-06-16 14:36       ` Take Ceara
2016-06-16 14:58         ` Wiles, Keith
2016-06-16 15:16           ` Take Ceara
2016-06-16 15:29             ` Wiles, Keith
2016-06-16 16:20               ` Take Ceara
2016-06-16 16:56                 ` Wiles, Keith
2016-06-16 16:59                   ` Wiles, Keith
2016-06-16 18:20                     ` Take Ceara
2016-06-16 19:33                       ` Wiles, Keith
2016-06-16 20:00                         ` Take Ceara
2016-06-16 20:16                           ` Wiles, Keith
2016-06-16 20:19                             ` Wiles, Keith
2016-06-16 20:27                               ` Take Ceara

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=20160613142836.GH15736@bricha3-MOBL3 \
    --to=bruce.richardson@intel.com \
    --cc=dev@dpdk.org \
    --cc=dumitru.ceara@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.