From: Eric Dumazet <eric.dumazet@gmail.com>
To: pradeep kumar nalla <pradeepkumar.nalla@gmail.com>,
netdev@vger.kernel.org
Subject: Re: skb length without fragments
Date: Mon, 8 Oct 2018 11:23:05 -0700 [thread overview]
Message-ID: <6b9500e2-b3eb-3c3c-3e52-d67ea0a7d51f@gmail.com> (raw)
In-Reply-To: <CAABr=eaZePxgwS=0fFhUMsXxd1T0PbcQ4-TJBOw4z4qqhEN_cA@mail.gmail.com>
On 10/08/2018 11:02 AM, pradeep kumar nalla wrote:
> Hi
>
> While testing my network driver with pktgen I could see an skb greater
> than 16K without fragments in xmit function. This lead to a fix in my
> driver that assumes when an SKB whose length is greater than 16K will
> come with fragments. Apart from pktgen what are the chances or
> possibilities of getting an SKB greater than 16K without fragments? .
> When I tried with tools like iperf/iper3/netperf, didn’t see a single
> incidence where the SKB length is greater than 16K and without frags.
> Even socket layer I see function alloc_skb_with_frags, does this mean
> all the larger packets come with frags.
>
There are cases where skb_linearize() calls happen, and then certainly
can feed a driver with a big linear skb.
Even if current tree would not hit this, you have to play safe and
do the check in the driver.
prev parent reply other threads:[~2018-10-09 1:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-08 18:02 skb length without fragments pradeep kumar nalla
2018-10-08 18:23 ` Eric Dumazet [this message]
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