[MUD-Dev] Re: Ethernet NICS, maximum connections..mud testing.

[Ben Greear]

On Sun, 9 Aug 1998, Chris Gray wrote:

> [Ben Greear:]
> 
>  >Try this:  write a 1 meg file to disk, 10 characters at a time, and
>  >do the same with 4k blocks.  Sending over a socket would be the
>  >should show the same graph.
> 
> Perhaps we should take this out of the MUD-Dev list.
> 
> ami-cg /home/cg % time a.out
> Writing 16777216 bytes in 10 byte chunks
> All done
> 0.78user 8.77system 0:09.74elapsed 97%CPU (0avgtext+0avgdata 0maxresident)k
> 0inputs+0outputs (63major+7minor)pagefaults 0swaps
> 
> ami-cg /home/cg % time a.out
> Writing 16777216 bytes in 4096 byte chunks
> All done
> 0.00user 0.27system 0:00.66elapsed 40%CPU (0avgtext+0avgdata 0maxresident)k
> 0inputs+0outputs (63major+7minor)pagefaults 0swaps
> 
> As expected, the larger writes are much faster. Note however that the
> effort on the smaller writes is almost entirely CPU time. The perfmeter
> goes up, and the CPU usage reported by 'time' is high. This is all as
> expected.

I guess I was not expecting the high CPU usage on the little packets.
With that in mind...I've no clue why it goes so slow :)

> The question is: why does my experiment run at such a low CPU utilization?
> Not why is it slow, but why does it run with the CPU mostly idle? I
> think you have been missing this point.
> 
> -- 
> Chris Gray     cg at ami-cg.GraySage.Edmonton.AB.CA
> 
> -- 
> MUD-Dev: Advancing an unrealised future.
> 


Ben Greear (greear at cyberhighway.net)  http://www.primenet.com/~greear 
Author of ScryMUD:  mud.primenet.com 4444
http://www.primenet.com/~greear/ScryMUD/scry.html