public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: James Kosin <JKosin@intcomgrp.com>
Cc: linux-kernel@vger.kernel.org, Linux Netdev List <netdev@vger.kernel.org>
Subject: Re: arm: Optimization for ethernet MAC handling at91_ether.c
Date: Tue, 12 Jan 2010 19:08:19 +0100	[thread overview]
Message-ID: <4B4CBA93.4090909@gmail.com> (raw)
In-Reply-To: <3DBBD805E3BA064A87F551C0E8BD36740289740E@MAILSRV.intcomgrp.com>

Le 12/01/2010 18:51, James Kosin a écrit :
> On 1/12/2010 11:40 AM, Eric Dumazet wrote:

>> If this happens once in a while, why do you want driver to retry the transmit ?
> 
> (a)  It would improve performance by allowing the ISR to handle the re-transmit in this case.
> (b)  It would help in the case of small glitches that may happen from external SDRAM without taxing the polling required to handle the re-transmit of the packet... ie: overhead required to re-queue and initiate a packet delivery... since the packet is already scheduled for delivery now.
> 

OK, but then this also adds an extra check for each tx completion.

I dont have this piece of hardware, but seeing it has a one skb tx queue (!),
I suppose TX performance is not very good anyway...


at91ether_interrupt() should probably handle tx completion before rx, to feed
next frame faster.


  reply	other threads:[~2010-01-12 18:08 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-12 15:39 arm: Optimization for ethernet MAC handling at91_ether.c James Kosin
2010-01-12 16:35 ` Eric Dumazet
2010-01-12 17:51   ` James Kosin
2010-01-12 18:08     ` Eric Dumazet [this message]
2010-01-12 18:42       ` James Kosin
2010-01-12 19:03         ` James Kosin
2010-01-12 19:24           ` Eric Dumazet
2010-01-12 19:39             ` James Kosin

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=4B4CBA93.4090909@gmail.com \
    --to=eric.dumazet@gmail.com \
    --cc=JKosin@intcomgrp.com \
    --cc=linux-kernel@vger.kernel.org \
    --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