Messages in this thread | | | Date | Wed, 4 Feb 2009 11:12:01 +0300 | From | Evgeniy Polyakov <> | Subject | Re: [PATCH v2] tcp: splice as many packets as possible at once |
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On Wed, Feb 04, 2009 at 07:19:47AM +0100, Willy Tarreau (w@1wt.eu) wrote: > Yes myri10ge for the optimal 4080, but with e1000 too (though I don't > remember the exact optimal value, I think it was slightly lower).
Very likely it is related to the allocator - the same allocation overhead to get a page, but 2.5 times bigger frame.
> For the myri10ge, could this be caused by the cache footprint then ? > I can also retry with various values between 4 and 9k, including > values close to 8k. Maybe the fact that 4k is better than 9 is > because we get better filling of all pages ? > > I also remember having used a 7 kB MTU on e1000 and dl2k in the past. > BTW, 7k MTU on my NFS server which uses e1000 definitely stopped the > allocation failures which were polluting the logs, so it's been running > with that setting for years now.
Recent e1000 (e1000e) uses fragments, so it does not suffer from the high-order allocation failures.
-- Evgeniy Polyakov
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