From: Tom Herbert <therbert@google.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH v2] Receive Packet Steering
Date: Fri, 17 Jul 2009 11:05:58 -0700 [thread overview]
Message-ID: <65634d660907171105s4989758ah533203d107924b6a@mail.gmail.com> (raw)
In-Reply-To: <20090716.194846.58845712.davem@davemloft.net>
On Thu, Jul 16, 2009 at 7:48 PM, David Miller <davem@davemloft.net> wrote:
>
> From: Tom Herbert <therbert@google.com>
> Date: Tue, 14 Jul 2009 16:28:01 -0700
>
> > Using the Toeplitz hash in steering lookup has given us about 10% more
> > maximum pps (2 different NICs), and we haven't really noticed negative
> > effects because of the extra descriptor overhead-- so I'm not going to
> > give up on it too easily!
>
> Do you have any idea why? Does Toeplitz distribute better?
> If so, that could be merely because either:
>
> 1) Our modulus avoidance scheme somehow decreases the distribution
> features of the hash
>
> 2) The way we feed data into the hash has a similar effect
>
> It's worth checking out.
The advantage is that Toeplitz, or any reasonable device provided
hash, allows packet steering to be done without taking any cache
misses on the packet itself. In particular, this helps with a NIC
that just provides Toeplitz hash (without multiQ),
next prev parent reply other threads:[~2009-07-17 18:06 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-04 4:03 [PATCH v2] Receive Packet Steering Tom Herbert
2009-05-04 5:30 ` Eric Dumazet
2009-05-04 6:10 ` Eric Dumazet
2009-05-04 7:13 ` Eric Dumazet
2009-05-12 17:28 ` Tom Herbert
2009-05-04 7:08 ` Eric Dumazet
2009-05-04 7:59 ` Andi Kleen
2009-05-04 18:22 ` Jarek Poplawski
2009-05-04 20:43 ` Jarek Poplawski
2009-06-10 8:23 ` David Miller
2009-06-15 5:54 ` Tom Herbert
[not found] ` <65634d660906142252y6f7fc021l844b172995c10044@mail.gmail.com>
2009-06-15 9:02 ` David Miller
2009-06-15 16:39 ` Tom Herbert
2009-06-15 23:18 ` David Miller
2009-07-13 17:49 ` David Miller
2009-07-13 22:04 ` Tom Herbert
2009-07-14 19:33 ` David Miller
2009-07-14 23:28 ` Tom Herbert
2009-07-17 2:48 ` David Miller
2009-07-17 18:05 ` Tom Herbert [this message]
2009-07-17 18:08 ` David Miller
2009-07-17 19:59 ` Tom Herbert
2009-07-18 3:54 ` David Miller
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=65634d660907171105s4989758ah533203d107924b6a@mail.gmail.com \
--to=therbert@google.com \
--cc=davem@davemloft.net \
--cc=netdev@vger.kernel.org \
/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).