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From: Eric Dumazet <eric.dumazet@gmail.com>
To: "Florian Westphal" <fw@strlen.de>,
	"Toke Høiland-Jørgensen" <toke@redhat.com>
Cc: "Toshiaki Makita" <makita.toshiaki@lab.ntt.co.jp>,
	"Felix Fietkau" <nbd@nbd.name>,
	"Rafał Miłecki" <zajec5@gmail.com>,
	"Toshiaki Makita" <toshiaki.makita1@gmail.com>,
	netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
	"Stefano Brivio" <sbrivio@redhat.com>,
	"Sabrina Dubroca" <sd@queasysnail.net>,
	"David Ahern" <dsahern@gmail.com>, "Jo-Philipp Wich" <jo@mein.io>,
	"Koen Vandeputte" <koen.vandeputte@ncentric.com>
Subject: Re: NAT performance regression caused by vlan GRO support
Date: Fri, 5 Apr 2019 04:00:20 -0700	[thread overview]
Message-ID: <d3aaaca4-41a6-d8fb-5156-9c8e7921c04a@gmail.com> (raw)
In-Reply-To: <20190405105151.7csiro6ib5zpaqsd@breakpoint.cc>



On 04/05/2019 03:51 AM, Florian Westphal wrote:
> Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>> As a first approximation, maybe just:
>>
>> if (!has_hardware_cksum_offload(netdev) && link_rate(netdev) <= 1Gbps)
>>   disable_gro();
> 
> I don't think its a good idea.  For local delivery case, there is no
> way to avoid the checksum cost, so might as well have GRO enabled.
> 

We might add a sysctl or a way to tell GRO layer :

Do not attempt checksumming if forwarding is enabled on the host.

Basically GRO if NIC has provided checksum offload.


  reply	other threads:[~2019-04-05 11:00 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-04 12:57 NAT performance regression caused by vlan GRO support Rafał Miłecki
2019-04-04 15:17 ` Toshiaki Makita
2019-04-04 20:22   ` Rafał Miłecki
2019-04-05  4:26     ` Toshiaki Makita
2019-04-05  5:48       ` Rafał Miłecki
2019-04-05  7:11         ` Rafał Miłecki
2019-04-05  7:14           ` Felix Fietkau
2019-04-05  7:58             ` Toshiaki Makita
2019-04-05  8:12               ` Rafał Miłecki
2019-04-05  8:24                 ` Rafał Miłecki
2019-04-05 10:18               ` Toke Høiland-Jørgensen
2019-04-05 10:51                 ` Florian Westphal
2019-04-05 11:00                   ` Eric Dumazet [this message]
2019-04-07 11:53 ` Rafał Miłecki
2019-04-07 11:54   ` Rafał Miłecki
2019-04-08 13:31     ` David Laight

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