netdev - Re: [PATCH net-next] ipv6: disable GSO on sockets hitting dst

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] [day] [month] [year] [list]

Message-Id: <20120519.040313.1890452580451494013.davem@davemloft.net>
Date:	Sat, 19 May 2012 04:03:13 -0400 (EDT)
From:	David Miller <davem@...emloft.net>
To:	eric.dumazet@...il.com
Cc:	netdev@...r.kernel.org, tore@....no
Subject: Re: [PATCH net-next] ipv6: disable GSO on sockets hitting
 dst_allfrag

From: Eric Dumazet <eric.dumazet@...il.com>
Date: Sat, 19 May 2012 09:51:44 +0200

> From: Eric Dumazet <edumazet@...gle.com>
> 
> If the allfrag feature has been set on a host route (due to an ICMPv6
> Packet Too Big received indicating a MTU of less than 1280), we hit a
> very slow behavior in TCP stack, because all big packets are dropped and
> only a retransmit timer is able to push one MSS frame every 200 ms.
> 
> One way to handle this is to disable GSO on the socket the first time a
> super packet is dropped. Adding a specific dst_allfrag() in the fast
> path is probably overkill since the dst_allfrag() case almost never
> happen.
> 
> Result on netperf TCP_STREAM, one flow :
> 
> Before : 60 kbit/sec
> After : 1.6 Gbit/sec
> 
> Reported-by: Tore Anderson <tore@....no>
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>
> Tested-by: Tore Anderson <tore@....no>

Applied.
--
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