Pitiful benchmark performance

Ulf Wiger <>
Sat Jun 9 16:12:48 CEST 2001


On Sat, 9 Jun 2001, Ulf Wiger wrote:


>I don't know, but I've never had the impression that Erlang was
>very quick to initialize. What happens if the clock is started
>by triggering it inside an already running VM?

(Since I can barely understand what I wrote myself:)
By "triggering it", I meant first starting the VM, and then 
running the benchmark from within Erlang. At least, this could 
give a perspective on how much of the 19 sec lies in just
starting Erlang. Of course, clocking by hand on my old Pentium
90, this still only saves you 2-3 seconds...

What would happen if you e.g. change INPUT_REDUCTIONS in erl_vm.h
from (2* CONTEXT_REDS) to CONTEXT_REDS, doubling the I/O poll
frequency?  (CONTEXT_REDS is set to 1000)

If basically all that happens in the erlang vm is that some 
process is waiting for I/O, ports may not be polled with any
predictably high frequency (then again, this is only guessing
wildly. Perhaps it effectively gives the ports even higher
priority...)


/Uffe
-- 
Ulf Wiger                                    tfn: +46  8 719 81 95
Senior System Architect                      mob: +46 70 519 81 95
Strategic Product & System Management    ATM Multiservice Networks
Data Backbone & Optical Services Division      Ericsson Telecom AB





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