public inbox for linux-rt-users@vger.kernel.org
 help / color / mirror / Atom feed
From: "Nebojša Ćosić" <nebojsa@asnn.org>
To: Stanislav Meduna <stano@meduna.org>
Cc: "linux-rt-users@vger.kernel.org" <linux-rt-users@vger.kernel.org>
Subject: Re: e1000e 82574L transmit latency?
Date: Tue, 28 May 2013 15:01:35 +0200	[thread overview]
Message-ID: <20130528150135.41a6d6fb@sth491dt.servo.net> (raw)
In-Reply-To: <51A4A6F7.5090909@meduna.org>


> Hi,
> 
> anyone has experience / knows of bugs (not the ASPM one) causing
> high (at least 70 ms) latency on Intel 82574L using the e1000e driver?
> 
> We have an instance of a connected device needing to be serviced
> each 100 ms reporting a timeout while our internal measurements
> show that the packets were given to the kernel max 30 ms apart.
> 
> These are raw packets, there is no other traffic on that interface,
> no kernel messages, no errors in the /sys/class/net/eth1/statistics/*
> and it happened after 5 days of uptime :/
> 
> I am using kernel 3.4 with RT PREEMPT - I note that the driver version
> there is 1.9.5 while in 3.9 it is 2.2.14. Anyone knows if the network
> drivers are back-portable without much hassle that far
> or whether this is a complicated task?
> 
> e1000-devel: please Cc: me when replying, I am not subscribed
> to the list.
> 
> Thanks

If you are having several processes/threads with different priorities
sending on same eth, combined with high cpu load on RT processes, than
it sounds a lot like a problem I had: Check
http://article.gmane.org/gmane.linux.rt.user/10163 for details

-- 
Nebojša
--
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply	other threads:[~2013-05-28 13:01 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-28 12:45 e1000e 82574L transmit latency? Stanislav Meduna
2013-05-28 13:01 ` Nebojša Ćosić [this message]
2013-05-28 13:49   ` Stanislav Meduna
2013-05-28 14:09     ` Nebojša Ćosić
2013-05-28 14:05   ` Stanislav Meduna
2013-05-28 14:15     ` Nebojša Ćosić

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=20130528150135.41a6d6fb@sth491dt.servo.net \
    --to=nebojsa@asnn.org \
    --cc=linux-rt-users@vger.kernel.org \
    --cc=stano@meduna.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