MAXSAVEDBLOCKS in netinet/tcp_sack.c

Matthew Dillon dillon at apollo.backplane.com
Tue Jul 5 10:36:45 PDT 2005


:Noritoshi Demizu wrote:
:
:> Sorry, actually, I always set net.inet.tcp.inflight_enable to zero
:> both on DragonFlyBSD and FreeBSD in my experiences (I know it is zero
:> on DragonFlyBSD by default, but I want to make it sure), because
:> unfortunately it reduces throughput in my experiences in an unexpected
:> way.
:Just some extra input: I can confirm this. During TCP-performance tests (on
:FreeBSD 5.4 machines) I saw a drop from around 700MBit/s to 300Mbit/s just
:by turning on 'inflight'. Quite substantial, I'd say. 
:
:-- 
:Pieter

    Well, you can mess around with the other related controls, but inflight
    is not designed to do well on performance tests, it is designed to manage
    an overloaded network in real life situations.  So if your network is
    overloaded and turning on inflight helps, and nobody complains about it,
    then it has served its purpose.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>





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