Netdev List
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Dave Taht <dave.taht@gmail.com>
Cc: John Fastabend <john.r.fastabend@intel.com>,
	Tom Herbert <therbert@google.com>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH v4 0/10] bql: Byte Queue Limits
Date: Tue, 29 Nov 2011 09:43:54 +0100	[thread overview]
Message-ID: <1322556234.2970.84.camel@edumazet-laptop> (raw)
In-Reply-To: <CAA93jw7prPymGuWdn0pgHXL81g19opm2=-T4msy-b_s2MJ9=Jw@mail.gmail.com>

Le mardi 29 novembre 2011 à 09:37 +0100, Dave Taht a écrit :
> On Tue, Nov 29, 2011 at 8:23 AM, John Fastabend
> <john.r.fastabend@intel.com> wrote:
> >
> > I wonder if we should consider enabling TSO/GSO per queue or per traffic
> > class on devices that support this. At least in devices that support
> > multiple traffic classes it seems to be a common usage case to put bulk
> > storage traffic (iSCSI) on a traffic class and low latency traffic on a
> > separate traffic class, VoIP for example.
> 
> 
> VOIP is a drop in the bucket.
> 
> Turning TSO off on TCP exiting the datacenter (or more specifically),
> destined anywhere there is potential tx/rx bandwidth disparity
> would be goooooood.
> 

If your cpu is fast enough (and they are most of the time), this makes
no difference at all.

Instead of consuming 3% of cpu with TSO, you'll consume 10% or 15% and
no difference seen on the wire.

Really, if you want to avoid bursts, TSO has litle to do with them.

  reply	other threads:[~2011-11-29  8:44 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-29  2:32 [PATCH v4 0/10] bql: Byte Queue Limits Tom Herbert
2011-11-29  4:23 ` Dave Taht
2011-11-29  7:02   ` Eric Dumazet
2011-11-29  7:07     ` Eric Dumazet
2011-11-29  7:23     ` John Fastabend
2011-11-29  7:45       ` Eric Dumazet
2011-11-29  8:03         ` John Fastabend
2011-11-29  8:37       ` Dave Taht
2011-11-29  8:43         ` Eric Dumazet [this message]
2011-11-29  8:51           ` Dave Taht
2011-11-29 14:57             ` Eric Dumazet
2011-11-29 16:24               ` Dave Taht
2011-11-29 17:06                 ` David Laight
2011-11-29 14:24     ` Ben Hutchings
2011-11-29 14:29       ` Eric Dumazet
2011-11-29 16:06         ` Dave Taht
2011-11-29 16:41           ` Ben Hutchings
2011-11-29 17:28     ` Rick Jones
2011-11-29 16:46 ` Eric Dumazet
2011-11-29 17:47   ` David Miller
2011-11-29 18:31     ` Tom Herbert
2011-12-01 16:50       ` Kirill Smelkov
2011-12-01 18:00         ` David Miller
2011-12-02 11:22           ` Kirill Smelkov
2011-12-02 11:57             ` Eric Dumazet
2011-12-02 12:26               ` Kirill Smelkov

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=1322556234.2970.84.camel@edumazet-laptop \
    --to=eric.dumazet@gmail.com \
    --cc=dave.taht@gmail.com \
    --cc=davem@davemloft.net \
    --cc=john.r.fastabend@intel.com \
    --cc=netdev@vger.kernel.org \
    --cc=therbert@google.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