Re: Overscheduling DOES happen with high web server load.
Greg Lindahl (lindahl@cs.virginia.edu)
Fri, 7 May 1999 19:09:30 -0400 (EDT)
> > Ok, you are right. The real problem is we are calculating goodness
> > O(A*B).
> >
> > A= Number of processes on the runqueue
> > B= Number of times schedule is called
>
> Don't underestimate the cost of searching the run queue. Put 10
> processes on the run queue and you more than double the cost of
> schedule() to another process. For 90+ tasks on the run queue, the
> cost is dominated by the linear search.
You are violently agreeing with Phil. The linear cost of searching the
run queue is represented by A in his expression. That was the point of
my little hack, which was to always take the first schedulable process
in the queue, merely to see if that made life much better. And it
seems to.
-- g
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