Date: Fri, 26 Sep 1997 07:37:24 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: dg@root.com Cc: tlambert@primenet.com, ccsanady@bob.scl.ameslab.gov, current@FreeBSD.ORG Subject: Re: TCP timers (Was: Re: new timeout routines) Message-ID: <199709260737.AAA16250@usr04.primenet.com> In-Reply-To: <199709260632.XAA21071@implode.root.com> from "David Greenman" at Sep 25, 97 11:32:52 pm
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> I like whatever scheme is the most efficient. Even an all-singing, > all-dancing system timer implementation that keeps everything sorted in > a binary tree is going to perform much worse than specialized code that > can do simple FIFO sorting by taking advantage of the fixed timeout > interval. On a busy machine like wcarchive, tens of thousands of delayed > acks can occur each second, so this needs to be optimized for efficiency > as much as possible. The extra call overhead that one would incur by having > a timer event per connection is plenty enough to make me cringe. What about inlining the insertion and removal function calls? That should end up being very low overhead... hopefully as low overhead as a seperate implementation. If it's not, then we should be using TCP's code for the system timers instead of the system timer code for TCP. ;-). > >The initial posting to which David responded wanted to use centralized > >timer code for all timing functions. I liked that idea, with the > > I don't like that idea, but maybe it's because my brain refuses to bend > around the idea that delayed-ack processing is just another connection > state. Heh. "Mei meind may very wiel SNNNNNIP!" -- Dr. Scott Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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