Messages in this thread | | | From | Andries.Brouwer@cwi ... | Date | Fri, 5 Sep 2003 11:16:05 +0200 (MEST) | Subject | Re: [PATCH] add_mouse_randomness |
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From oxymoron@waste.org Fri Sep 5 07:01:30 2003 From: Matt Mackall <mpm@selenic.com>
> Today: > Every keypress and every key release causes two calls of > add_mouse_randomness and one call of add_keyboard_randomness. > Key repeat causes lots of calls of add_mouse_randomness. > > The random driver contains a mechanism (delta, delta2, delta3) > for estimating the amount of entropy in a stream of moments in > time. But the fact that every event causes two calls, very > quickly after each other, poisons this mechanism, and makes us > overestimate.
The real problem is that the deltas are calculated from gigahertz cycle counters, but yes, we're calling too frequently and blowing away useful history. I've experimented with making the deltas per-source as well.
I wouldnt know what is wrong with using gigahertz cycle counters. The deltas are already per-source. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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