mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Alexey Vlasov <renton@renton.name>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	netdev <netdev@vger.kernel.org>
Subject: Re: Packet time delays on multi-core systems
Date: Thu, 30 Sep 2010 16:23:21 +0400	[thread overview]
Message-ID: <20100930122321.GA1575@beaver.vrungel.ru> (raw)
In-Reply-To: <1285828432.5211.812.camel@edumazet-laptop>

On Thu, Sep 30, 2010 at 08:33:52AM +0200, Eric Dumazet wrote:
> Le jeudi 30 septembre 2010 ?? 10:24 +0400, Alexey Vlasov a ??crit :
> > Here I found some dude with the same problem:
> > http://lkml.org/lkml/2010/7/9/340
> > 
> 
> In your opinion its the same problem.
> 
> But the description you gave is completely different.
> 
> You have time skew only when activating a particular iptables rule.
 
Well I put interrups from NIC, namely tx/rx query, to different
processors and got normal pings by adding LOG rule.

I also found that overruns is constantly growing, I don't know if these are connected.
RX packets:2831439546 errors:0 dropped:134726 overruns:947671733 frame:0
TX packets:2880849825 errors:0 dropped:0 overruns:0 carrier:0

Rather strange that only one processor was involved, even in top was
clear that ksoftirqd eats the first processor up to 100%. 

Here goes the typical distribution of interrups on new servers:
           CPU0    CPU1    CPU2    CPU3 ... CPU23
752:         11       0       0       0 ...     0 PCI-MSI-edge eth0
753: 2799366721       0       0       0 ...     0 PCI-MSI-edge eth0-rx3
754: 2821840553       0       0       0 ...     0 PCI-MSI-edge eth0-rx2
755: 2786117044       0       0       0 ...     0 PCI-MSI-edge eth0-rx1
756: 2896099336       0       0       0 ...     0 PCI-MSI-edge eth0-rx0
757: 1808404680       0       0       0 ...     0 PCI-MSI-edge eth0-tx3
758: 1797855130       0       0       0 ...     0 PCI-MSI-edge eth0-tx2
759: 1807222032       0       0       0 ...     0 PCI-MSI-edge eth0-tx1
760: 1820309360       0       0       0 ...     0 PCI-MSI-edge eth0-tx0

On the old ones:
           CPU0       CPU1       CPU2  ...      CPU8
502:  522320256  522384039  522327386  ... 522380267 PCI-MSI-edge eth0

-- 
BRGDS. Alexey Vlasov.

  reply	other threads:[~2010-09-30 12:25 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-29 19:18 Alexey Vlasov
2010-09-29 21:45 ` Eric Dumazet
2010-09-30  6:24   ` Alexey Vlasov
2010-09-30  6:33     ` Eric Dumazet
2010-09-30 12:23       ` Alexey Vlasov [this message]
2010-09-30 12:44         ` Eric Dumazet
2010-09-30 17:37           ` Alexey Vlasov
2010-09-30 18:03             ` Eric Dumazet
2010-09-30 18:15               ` Alexey Vlasov
2010-09-30 18:52                 ` Eric Dumazet
2010-10-01 10:16                   ` Alexey Vlasov
2010-10-01 12:59                     ` Eric Dumazet
2010-10-01 14:18                       ` Alexey Vlasov
2010-10-01 15:27                         ` Eric Dumazet
2010-10-01 18:54                           ` Jeff Kirsher
2010-09-30 12:30   ` Alexey Vlasov
2010-09-30 12:46     ` Eric Dumazet

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=20100930122321.GA1575@beaver.vrungel.ru \
    --to=renton@renton.name \
    --cc=eric.dumazet@gmail.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

all inboxes | Powered by JetHome®