Re: doubt on auto tuning in 2.4 kernels

[Eric Weigle <ehw@lanl.gov>]

> Hi,
> Does anybody know if auto tuning can be turned off in 2.4 kernels. If yes
> can some body tell me how to do so. Seems like Auto tuning of socket buffers
> is overriding my large buffer settings.
> Any help in this regard would be appreciated.

It can't be turned off. It is a way of managing non-swappable kernel memory
and if you are in memory pressure, then you may not get 'ideal' buffers.

There are a couple things you *can* do, though; take a look at
Documentation/networking/ip-sysctl.txt in the kernel source. In particular,
tcp_wmem and tcp_rmem. It's not a good idea to set min and max the
same, but if you make your default the 'ideal' and the min/max slightly
less/more you should get good results.

Also look at your settings in /proc/sys/net/core/[rw]mem_[max|default].

Here are a couple of tuning links I've found useful:

	http://www.psc.edu/networking/perf_tune.html#Linux
	http://www-didc.lbl.gov/tcp-wan.html
 
-Eric

--
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 Eric H. Weigle   CCS-1, RADIANT team
 ehw@lanl.gov     Los Alamos National Lab
 (505) 665-4937   http://home.lanl.gov/ehw/
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