Re: [RFC] frandom - fast random generator module
From: Nick Piggin
Date: Thu Oct 16 2003 - 05:56:20 EST
Eli Billauer wrote:
Frandom is the faster version of the well-known /dev/urandom random
number generator. Not instead of, but rather as a supplement, when
pseudorandom data is needed at high rate. Few tests so far show that
frandom is 10-50 times faster than urandom.
Without looking at the code, why should this be done in the kernel?
I suppose you're asking why having a /dev/frandom device at all. Why
not let everyone write their own little random generator (based upon
well-known C functions) whenever random data is needed.
Yes, a userspace solution that makes use of the existing kernel random
number source if needed.
There are plenty of handy things in the kernel, that could be done in
userspace. /dev/zero is my favourite example, but I'm sure there are
other cases where things were put in the kernel simply because people
found them handy. Which is a good reason, if you ask me.
There is probably a lot in the kernel that can (and a lot that should) be
done in userspace (although I'm not sure /dev/zero is one of them).
This doesn't mean having them in the kernel is a good idea because they are
handy. I'm not passing judgement on your module though - I was just
wondering
why it is in kernel.
Besides, it's quite easy to do something wrong with random numbers. By
having a good source of random data, I suppose we can spare a lot of
people the headache of getting their own user-space application right
for the one-off thing they want to do.
Although we do have 2 types of random number sources in the kernel. I'm not
sure we'd want to keep adding them as the need arises. Maybe if it were
a very
general and configurable one, but AFAIKS frandom is not.
Cheers,
Nick
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