netdev - Re: tcp wifi upload performance and lots of ACKs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAEnQRZDH6te-xa1E5aohs7+MWfAwsx-eOCP1tQ9vZRDmEO=C+Q@mail.gmail.com>
Date:	Mon, 4 Jun 2012 23:15:48 +0300
From:	Daniel Baluta <dbaluta@...acom.com>
To:	Ben Greear <greearb@...delatech.com>
Cc:	netdev <netdev@...r.kernel.org>
Subject: Re: tcp wifi upload performance and lots of ACKs

On Mon, Jun 4, 2012 at 11:09 PM, Ben Greear <greearb@...delatech.com> wrote:
> On 06/04/2012 12:22 PM, Daniel Baluta wrote:
>>
>> On Mon, Jun 4, 2012 at 9:29 PM, Ben Greear<greearb@...delatech.com>
>>  wrote:
>>>
>>> I'm going some TCP performance testing on wifi ->  LAN interface
>>> connections.
>>>  With
>>> UDP, we can get around 250Mbps of payload throughput.  With TCP, max is
>>> about 80Mbps.
>>>
>>> I think the problem is that there are way too many ACK packets, and
>>> bi-directional
>>> traffic on wifi interfaces really slows things down.  (About 7000 pkts
>>> per
>>> second in
>>> upload direction, 2000 pps download.  And the vast majority of the
>>> download
>>> pkts
>>> are 66 byte ACK pkts from what I can tell.)
>>>
>>> Kernel is 3.3.7+
>>>
>>> Anyone know of any tuning parameters that would let the receiving socket
>>> wait a
>>> bit longer and send more ACK data in fewer packets?
>>
>>
>> An ACK is generated after every second full sized segment or a timeout
>> expires.
>>
>> Currently, there is no way to tune these parameters. Here is an
>> experimental
>> patch [1]. If anyone, thinks that this patch has a chance to get accepted
>> I will be happily try to further improve it.
>
>
> It looks like it could be useful for my case, but I would also want
> per-socket options to set the min/max ack delay so that the settings
> are not just system-wide.
>
> I can at least test this, and perhaps even hack on the code if
> you are not interested in the per-socket settings...

Yes, indeed this should be a per socket option. I will be
back with a patch in the next days.

Meanwhile, it would be great if you could test my previous patch.

thanks,
Daniel.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html