From: Thomas Graf <tgraf@suug.ch>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: davem@davemloft.net, netdev@vger.kernel.org, foraker1@llnl.gov
Subject: Re: [PATCH net] tcp: Don't collapse if resulting skb could overflow skb->csum_start
Date: Thu, 28 Feb 2013 16:45:02 +0000 [thread overview]
Message-ID: <20130228164502.GD7558@casper.infradead.org> (raw)
In-Reply-To: <1362068326.15793.33.camel@edumazet-glaptop>
On 02/28/13 at 08:18am, Eric Dumazet wrote:
> but.... what is the value of skb_availroom(to) ?
>
> The earlier test at line 2302 should already guard this case ?
>
> /* Punt if not enough space exists in the first SKB for
> * the data in the second
> */
> if (skb->len > skb_availroom(to))
> break;
Only if it is guaranteed that we never see an MSS > 64K.
Assuming that is true forever, then a21d45726 (tcp: avoid order-1
allocations on wifi and tx path) does in fact resolve this
issue at the cost of not being able to use the extra room
kmalloc() might have given us in __alloc_skb() for collapsing.
Was that an intentional side effect of a21d45726?
next prev parent reply other threads:[~2013-02-28 16:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-28 10:26 [PATCH net] tcp: Don't collapse if resulting skb could overflow skb->csum_start Thomas Graf
2013-02-28 16:18 ` Eric Dumazet
2013-02-28 16:45 ` Thomas Graf [this message]
2013-02-28 17:35 ` Eric Dumazet
2013-02-28 17:40 ` Eric Dumazet
2013-02-28 19:23 ` Thomas Graf
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