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From: arno@natisbad•org (Arnaud Ebalard)
To: linux-arm-kernel@lists•infradead.org
Subject: [BUG,REGRESSION?] 3.11.6+,3.12: GbE iface rate drops to few KB/s
Date: Thu, 21 Nov 2013 22:51:09 +0100	[thread overview]
Message-ID: <871u298lv6.fsf@natisbad.org> (raw)
In-Reply-To: 20131121004430.GX8581@1wt.eu

Hi,

Willy Tarreau <w@1wt•eu> writes:

> OK it paid off. And very well :-)
>
> I did it at once and it worked immediately. I generally don't like this
> because I always fear that some bug was left there hidden in the code. I have
> only tested it on the Mirabox, so I'll have to try on the OpenBlocks AX3-4 and
> on the XP-GP board for some SMP stress tests.
>
> I upgraded my Mirabox to latest Linus' git (commit 5527d151) and compared
> with and without the patch.
>
>   without :
>       - need at least 12 streams to reach gigabit.
>       - 60% of idle CPU remains at 1 Gbps
>       - HTTP connection rate on empty objects is 9950 connections/s
>       - cumulated outgoing traffic on two ports reaches 1.3 Gbps
>
>   with the patch :
>       - a single stream easily saturates the gigabit
>       - 87% of idle CPU at 1 Gbps (12 streams, 90% idle at 1 stream)
>       - HTTP connection rate on empty objects is 10250 connections/s
>       - I saturate the two gig ports at 99% CPU, so 2 Gbps sustained output.
>
> BTW I must say I was impressed to see that big an improvement in CPU
> usage between 3.10 and 3.13, I suspect some of the Tx queue improvements
> that Eric has done in between account for this.
>
> I cut the patch in 3 parts :
>    - one which reintroduces the hidden bits of the driver
>    - one which replaces the timer with the IRQ
>    - one which changes the default Tx coalesce from 16 to 4 packets
>      (larger was preferred with the timer, but less is better now).
>
> I'm attaching them, please test them on your device.

Well, on the RN102 (Armada 370), I get the same results as with your
previous patch, i.e. netperf and nginx saturate the link. Apache still
lagging behind though.

> Note that this is *not* for inclusion at the moment as it has not been
> tested on the SMP CPUs.

I tested it on my RN2120 (2-core armada XP): I got no problem and the
link saturated w/ apache, nginx and netperf. Good work!

Cheers,

a+

  reply	other threads:[~2013-11-21 21:51 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-10 13:53 [BUG,REGRESSION?] 3.11.6+,3.12: GbE iface rate drops to few KB/s Arnaud Ebalard
2013-11-12  6:48 ` Cong Wang
2013-11-12  7:56   ` Arnaud Ebalard
2013-11-12  8:36     ` Willy Tarreau
2013-11-12  9:14       ` Arnaud Ebalard
2013-11-12 10:01         ` Willy Tarreau
2013-11-12 15:34           ` Arnaud Ebalard
2013-11-13  7:22             ` Willy Tarreau
2013-11-17 14:19               ` Willy Tarreau
2013-11-17 17:41                 ` Eric Dumazet
2013-11-19  6:44                   ` Arnaud Ebalard
2013-11-19 13:53                     ` Eric Dumazet
2013-11-19 17:43                       ` Willy Tarreau
2013-11-19 18:31                         ` Eric Dumazet
2013-11-19 18:41                           ` Willy Tarreau
2013-11-19 23:53                             ` Arnaud Ebalard
2013-11-20  0:08                               ` Eric Dumazet
2013-11-20  0:35                                 ` Willy Tarreau
2013-11-20  0:43                                   ` Eric Dumazet
2013-11-20  0:52                                     ` Willy Tarreau
2013-11-20  8:50                               ` Thomas Petazzoni
2013-11-20 19:21                                 ` Arnaud Ebalard
2013-11-20 19:11                               ` Willy Tarreau
2013-11-20 19:26                                 ` Arnaud Ebalard
2013-11-20 21:28                                 ` Arnaud Ebalard
2013-11-20 21:54                                   ` Willy Tarreau
2013-11-21  0:44                                     ` Willy Tarreau
2013-11-21 21:51                                       ` Arnaud Ebalard [this message]
2013-11-21 21:52                                         ` Willy Tarreau
2013-11-21 22:00                                           ` Eric Dumazet
2013-11-21 22:55                                             ` Arnaud Ebalard
2013-11-21 23:23                                               ` Rick Jones
     [not found]                                       ` <20131121183834.GB18513@1wt.eu>
2013-11-21 19:04                                         ` ARM network performance and dma_mask (was: [BUG,REGRESSION?] 3.11.6+,3.12: GbE iface rate drops to few KB/s) Thomas Petazzoni
2013-11-21 21:51                                           ` ARM network performance and dma_mask (was: [BUG, REGRESSION?] 3.11.6+, 3.12: " Willy Tarreau
2013-11-21 22:01                                         ` ARM network performance and dma_mask Rob Herring
2013-11-21 22:13                                           ` Willy Tarreau
2013-11-20 17:12                   ` [BUG,REGRESSION?] 3.11.6+,3.12: GbE iface rate drops to few KB/s Willy Tarreau
2013-11-20 17:30                     ` Eric Dumazet
2013-11-20 17:38                       ` Willy Tarreau
2013-11-20 18:52                       ` David Miller
2013-11-20 17:34                     ` Willy Tarreau
2013-11-20 17:40                       ` Eric Dumazet
2013-11-20 18:15                         ` Willy Tarreau
2013-11-20 18:21                           ` Eric Dumazet
2013-11-20 18:29                             ` Willy Tarreau
2013-11-20 19:22                           ` Arnaud Ebalard
2013-11-18 10:09                 ` David Laight
2013-11-18 10:52                   ` Willy Tarreau
2013-11-18 10:26                 ` Thomas Petazzoni
2013-11-18 10:44                   ` Simon Guinot
2013-11-18 16:54                     ` Stephen Hemminger
2013-11-18 17:13                       ` Eric Dumazet
2013-11-18 10:51                   ` Willy Tarreau
2013-11-18 17:58                     ` Florian Fainelli

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