netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Claudiu Manoil <claudiu.manoil@freescale.com>
To: David Miller <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>
Subject: Re: [PATCH net-next v2 0/2] gianfar: Tx timeout issue
Date: Tue, 11 Mar 2014 10:10:22 +0200	[thread overview]
Message-ID: <531EC4EE.8080104@freescale.com> (raw)
In-Reply-To: <20140310.131827.672807362272151307.davem@davemloft.net>

On 3/10/2014 7:18 PM, David Miller wrote:
> From: Claudiu Manoil <claudiu.manoil@freescale.com>
> Date: Fri, 7 Mar 2014 14:42:44 +0200
>
>> There's an older Tx timeout issue showing up on etsec2 devices
>> with 2 CPUs.  I pinned this issue down to processing overhead
>> incurred by supporting multiple Tx/Rx rings, as explained in
>> the 2nd patch below.  But before this, there's also a concurency
>> issue leading to Rx/Tx spurrious interrupts, addressed by the
>> 'Tx NAPI' patch below.
>> The Tx timeout can be triggered with multiple Tx flows,
>> 'iperf -c -N 8' commands, on a 2 CPUs etsec2 based (P1020) board.
>
> Series applied, thanks.
>
>

Thanks David.
However there's a problem with the second patch:
http://patchwork.ozlabs.org/patch/327941/
(gianfar: Use Single-Queue polling for "fsl,etsec2")

According to my comments, I retracted the patch because
of null access in gfar_of_init(): priv is not instantiated
at that time, which makes the run time checks (to limit
the number of supported queues) to be tricky.

What do you prefer: an additional separate patch to fix this
null access issue, or to revert the existing patch?

Another point is that the "Use Single-Queue polling..." patch
(http://patchwork.ozlabs.org/patch/327941/)
aims to obsolete the multi-queue polling, i.e. supporting
multiple queues per single NAPI instance.  How do you fill
about removing multi-queue polling support from the driver?
Is there a point for a linux eth driver to support more than
a Rx/Tx queue per NAPI instance?

Thanks again.
Claudiu

      reply	other threads:[~2014-03-11  8:10 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-07 12:42 [PATCH net-next v2 0/2] gianfar: Tx timeout issue Claudiu Manoil
2014-03-07 12:42 ` [PATCH net-next v2 1/2] gianfar: Separate out the Tx interrupt handling (Tx NAPI) Claudiu Manoil
2014-03-07 12:42 ` [PATCH net-next v2 2/2] gianfar: Use Single-Queue polling for "fsl,etsec2" Claudiu Manoil
2014-03-07 14:50   ` Claudiu Manoil
2014-03-10 17:18 ` [PATCH net-next v2 0/2] gianfar: Tx timeout issue David Miller
2014-03-11  8:10   ` Claudiu Manoil [this message]

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=531EC4EE.8080104@freescale.com \
    --to=claudiu.manoil@freescale.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).