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  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]
Date:	Sun, 6 Dec 2015 13:30:13 -0800
From:	Tom Herbert <>
To:	Alexander Duyck <>
Cc:	David Miller <>,
	Hannes Frederic Sowa <>,
	John Linville <>,
	Jesse Gross <>,
	Anjali Singhai Jain <>,
	Netdev <>,
	Kiran Patil <>
Subject: Re: [PATCH v1 1/6] net: Generalize udp based tunnel offload

On Sun, Dec 6, 2015 at 10:44 AM, Alexander Duyck
<> wrote:
> On Sun, Dec 6, 2015 at 8:31 AM, Tom Herbert <> wrote:
>>> The only spot I think you and I disagreed on was the approach.  I
>>> don't know if the hard push back does anything but punish the users by
>>> delaying the time needed to find a reasonable solution.  I really
>>> think if we are going to get the hardware vendors to change their
>>> behavior we have to create a market demand for it.  Having a bit of
>>> marketable data showing the folly of this approach versus the 1's
>>> compliment checksum would probably do more to encourage and/or shame
>>> them into it than simply pushing for this based on engineering
>>> opinion.
>> I don't know what "marketable data" means. But I do know that we're
>> like 70 postings into this thread, into the third patch set regarding
>> this, yet nobody has bothered to contribute any data on what these
>> patches do and what the quantifiable benefits are with HW offload of
>> these protocols. I would test this stuff myself, but I don't have
>> access to any NICs with necessary support. If someone else can start
>> testing and providing meaningful data it would be most helpful...
> Here is an example of something kind of like what I am talking about:
> I have seen evidence of the gains first hand.  The biggest gain ends
> up being the result of GRO, and you cannot make use of GRO without
> some form of Rx checksum offload.
Right, but we recoup the gains of GRO simply by enabling the UDP
checksum. This works for all the UDP encapsulations, and probably
about all NICs in deployment. You don't need protocol specific
offloads for this. I have posted performance data many times on this,
it is a clear win.
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists