Re: [PATCH v2 net-next] net: introduce gro_frag_list_enable sysctl

On Sat, 2013-11-02 at 21:43 +0400, Oleg A.Arkhangelsky wrote:

30.10.2013, 06:33, "David Miller" [off-list ref]:

quoted

GRO should always win, even on a router, because it decreases the
number of fundamental operations (routing lookups) that the stack
needs to perform.

Yes, unless the case when you're using Linux as IP router which is
forwarding 500K mixed IP (TCP and UDP) flows traffic @ 10-20 Gbit/s.
Then GRO is unnecessarily overhead, cause there's no possibility to
accumulate adequate GRO list in such scenario.

This was assuming the aggregation factor was not 0.

Even with 500K flows, you can have typically bursts of two packets per
flow.

Thats one of the reason why I chose to default
/proc/sys/net/ipv4/tcp_min_tso_segs to 2