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: <20110612095131.6d924082@konijn>
Date:	Sun, 12 Jun 2011 09:51:31 +0200
From:	Joris van Rantwijk <joris@...isvr.nl>
To:	Ben Hutchings <bhutchings@...arflare.com>
Cc:	netdev@...r.kernel.org
Subject: Re: Question about LRO/GRO and TCP acknowledgements


On 2011-06-12, Ben Hutchings <bhutchings@...arflare.com> wrote:
> LRO implementations (and GRO) are expected to put the actual segment
> size in skb_shared_info(skb)->gso_size on the aggregated skb.  TCP
> will then use that rather than the aggregated payload size when
> deciding whether to defer an ACK.

Thanks. I see that indeed gso_size is being used for MSS calculations
instead of the total GRO size.

However, I'm not sure that this completely answers my question.
I am not so much concerned about quick ACK vs delayed ACK.
Instead, I'm looking at the total number of ACKs transmitted.
The sender depends on the _number_ of ACKs to update its congestion
window.

As far as I can see, current code will send just one ACK per coalesced
GRO bundle, while the sender expects one ACK per two segments.

Thanks,
Joris.
--
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

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ