netdev - Re: [PATCH 2/2] v2 GRE: Add segmentation offload for GRE

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: <CALnjE+p0m7E7vH20M9mXuNiFG4iUpAsoyjW7ugez3ch=RdkVcw@mail.gmail.com>
Date:	Thu, 24 Jan 2013 19:38:16 -0800
From:	Pravin Shelar <pshelar@...ira.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	netdev@...r.kernel.org, jesse@...ira.com
Subject: Re: [PATCH 2/2] v2 GRE: Add segmentation offload for GRE

On Thu, Jan 24, 2013 at 5:34 PM, Eric Dumazet <eric.dumazet@...il.com> wrote:
> On Thu, 2013-01-24 at 16:14 -0800, Pravin Shelar wrote:
>
>> I think this patch does fix csum issue without causing any performance
>> regression. So this patch shld be enough to solve GRE-GSO issue. Once
>> you have fix, this code can be optimized even more.
>
> It adds the extra copy, since you assume no SG capability so
> skb_segment() _does_ a copy.
>
OK,I wil use device features.

> As the checksum is needed, its true the copy is almost not noticed,
> but one day NIC will be able to perform the checksum for us.
> (Maybe its already the case for some of them)
>
> I would first fix the checksum issue in a generic way, then
> apply this patch on top of the fix, so that we can use SG and avoid
> the extra copy for the typical tcp_sendmsg()

I thought you were working on the fix. If not I will post patch.
>
> It seems you focus on the TAP use case only, seeing you removed
> code that doesn't work for TAP but do work for regular locally
> terminated flows.
>
I have tested patch with GRE TAP and non TAP devices.

> You did a lot of implementation choices and none of them
> are described in a changelog, making future work a bit hard.
>

ok. I will update changelog.
--
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