[MUD-Dev] Re: lurker emerges

["T. Alexander Popiel" <popiel#snugharbor,com>]

In message:  <13773.64266.876212.231468#arioch,tky.hut.fi>
             Petri Virkkula <pvirkkul#iki,fi> writes:
>>>>>> "Chris" == Chris Gray <cg#ami-cg,GraySage.Edmonton.AB.CA> writes:
>
>Chris> In general, I think its clear that threading will only actually
>Chris> increase your speed if your system has multiple CPUs.
>
>	That's only true if your program is CPU bound. If the program
>	is I/O bound then count of physical disks is more relevaant
>	factor. In a mixed case I would use (this is only a guess)
>	x+2*y as formula for optimal thread count (x is count of CPUs
>	and y is count of physical disks), count of physical disks are
>	multiplied with 2 to keep disks busy all the time.

*blink blink*

You seem to assume that it is impossible for a single thread to keep
even one I/O device continuously busy.  Whatever happened to double-
buffering and non-blocking I/O?  Has that art actually been lost in
the annals of time?

>Chris> Threading has overhead over non-threading, and there isn't
>Chris> anything you can do about that.
>
>	Don't forget that non-threading has overhead too: if there is
>	multiple file descriptors then select'ing and going through
>	fd_sets can burns CPU time too.

While this is true, this overhead is something that a creative
programmer can manage and reduce, while the overhead of multiple
threads is untouchably bound in the OS kernel.

I prefer problems that I have at least some hope of fixing.

- Alex