From: David Miller <davem@davemloft.net>
To: nhorman@tuxdriver.com
Cc: netdev@vger.kernel.org, jhs@mojatatu.com,
netem@lists.linux-foundation.org, eric.dumazet@gmail.com,
stephen@networkplumber.org
Subject: Re: [PATCHv4] netem: Segment GSO packets on enqueue
Date: Tue, 03 May 2016 00:34:03 -0400 (EDT) [thread overview]
Message-ID: <20160503.003403.425735624710254974.davem@davemloft.net> (raw)
In-Reply-To: <1462206015-3484-1-git-send-email-nhorman@tuxdriver.com>
From: Neil Horman <nhorman@tuxdriver.com>
Date: Mon, 2 May 2016 12:20:15 -0400
> This was recently reported to me, and reproduced on the latest net kernel,
> when attempting to run netperf from a host that had a netem qdisc attached
> to the egress interface:
...
> The problem occurs because netem is not prepared to handle GSO packets (as it
> uses skb_checksum_help in its enqueue path, which cannot manipulate these
> frames).
>
> The solution I think is to simply segment the skb in a simmilar fashion to the
> way we do in __dev_queue_xmit (via validate_xmit_skb), with some minor changes.
> When we decide to corrupt an skb, if the frame is GSO, we segment it, corrupt
> the first segment, and enqueue the remaining ones.
>
> tested successfully by myself on the latest net kernel, to which this applies
>
> Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Applied and queued up for -stable, thanks Neil.
prev parent reply other threads:[~2016-05-03 4:34 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-26 17:43 [PATCH] netem: Segment GSO packets on enqueue Neil Horman
2016-04-26 18:49 ` Eric Dumazet
2016-04-26 19:00 ` Neil Horman
2016-04-26 20:19 ` Eric Dumazet
2016-04-27 11:27 ` Neil Horman
2016-04-28 20:09 ` [PATCHv2] " Neil Horman
2016-04-28 20:58 ` Eric Dumazet
2016-04-29 1:20 ` Neil Horman
2016-04-29 17:35 ` [PATCHv3] " Neil Horman
2016-04-29 18:09 ` Eric Dumazet
2016-04-29 18:19 ` Stephen Hemminger
2016-04-30 13:30 ` Neil Horman
2016-05-02 16:20 ` [PATCHv4] " Neil Horman
2016-05-02 16:56 ` Eric Dumazet
2016-05-03 4:34 ` David Miller [this message]
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