From: David Miller <davem@davemloft.net>
To: edumazet@google.com
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH net-next] net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends
Date: Thu, 19 Apr 2018 13:45:32 -0400 (EDT) [thread overview]
Message-ID: <20180419.134532.668231899611153609.davem@davemloft.net> (raw)
In-Reply-To: <20180418184315.48704-1-edumazet@google.com>
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 18 Apr 2018 11:43:15 -0700
> After working on IP defragmentation lately, I found that some large
> packets defeat CHECKSUM_COMPLETE optimization because of NIC adding
> zero paddings on the last (small) fragment.
>
> While removing the padding with pskb_trim_rcsum(), we set skb->ip_summed
> to CHECKSUM_NONE, forcing a full csum validation, even if all prior
> fragments had CHECKSUM_COMPLETE set.
Oops.
> We can instead compute the checksum of the part we are trimming,
> usually smaller than the part we keep.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Looks good, applied, thanks Eric.
next prev parent reply other threads:[~2018-04-19 17:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-18 18:43 [PATCH net-next] net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends Eric Dumazet
2018-04-19 17:45 ` David Miller [this message]
2018-04-19 18:18 ` Alexander Duyck
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