On Thu, Nov 07, 2013 at 09:40:12PM -0800, Eric Dumazet wrote:

On Fri, 2013-11-08 at 13:21 +0800, Herbert Xu wrote:

quoted

My point is that even if you did that GRO with your frag_list
patch should still be a win because the stack prior to the qdisc
gets run once instead of two or three times.

OK, lets me repeat again.

64KB packet receive/aggregation time is more than 540 us on 1Gbps link.

I presume you're still talking about the case where we're CPU-
bound on receive.  In that case I totally agree that you need to
impose a limit on the NAPI/GRO run so that we don't keep doing GRO
forever.

However, the limit should be based on time and not an arbitrary
number such as MAX_SKB_FRAGS.  IOW relying on not having a frag_list
to provide a bound to GRO is just wrong.

Cheers,
-- 
Email: Herbert Xu [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
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