Subject: Stupid Q on prob Calculation
To: None <>
From: Sumantra Kundu <>
List: tech-kern
Date: 07/15/2006 10:39:50
       I am stuck at a very stupid point in calculating the
following probability inside the kernel. Here is what  i need to do:
              congestion prob =    [{(a/b)* log (a/b)}/(log (b)] * (c/d).
a, b, are freq of invocations (integers) while c and d are time
difference (integers)

I know that its not possible to use floating point ops since the
kernel does not save FPU states (without messing up user
apps)...However, I do need **accurate** value of this quantity since
it basically estimates the degree of penalty of  the process.. Prev. I
had used all ops which are multiples of 2 but this one has thrown be
off..Now, I am getting all zeros (rightly so) iside the kernel..

Any hints/suggestions on how shud I go around this? I looked in the
altq codes and most of them (ewma ) uses multiples of 2..