Re: Comments on the KSE option

On Saturday 28 October 2006 13:34, Garance A Drosihn wrote:

> I think we have different ideas of what is the goal is with this
> claim of "fairness".
>
> If I understand it right, it is *not* that some static code in the
> kernel is going to decide which applications are fair and which ones
> are not fair.  IIIRC, what Julian wants to do is provide a way that
> the administrator can make that decision.  The administrator will
> have a way to throttle some thread-crazy process, but only if the
> *administrator* wants to do that.
>
> If the machine is for a single user, then that user will probably
> set "N" to a high value.  But if the machine has a lot of users on
> it, then the administrator of that machine may want to set "N" to
> the number of CPU's on the system, or maybe the number of CPU's
> minus 1.  And if the users don't like that, then they can go buy
> their own damn machine instead of using the machine someone else
> bought and is allowing them to access for free.
>
> At RPI we have both kinds of machines.  Machines owned by a single
> user, and machines which have multiple students ssh'ed into at the
> same time.  I can see wanting to throttle thread-crazy processes on
> some machines, and not wanting any throttling at all on others.
>
> ...but it has been a few years since the presentation that I remember
> Julian giving about this, so maybe I am not remembering it correctly.
> I do remember that whatever it was, it sounded pretty reasonable at
> the time.   :-)

but you know pthread_create call() is more complex and diffcult to use
than fork() which does not need any parameter, before freebsd has
native thread support, the whole FreeBSD world is using fork(), and I 
have not seen a single complaint that postgresql should be rewritten
because it is using too much CPU and driving other users out, same for
Apache web server, why should threaded application be a culprit ?

David Xu