On Tue, 2008-12-02 at 15:50 -0800, Arjan van de Ven wrote:Matt Mackall wrote:If we oops or warn while picking a timesource, we'll have lots of fun?we really only need to mix in the tsc; ktime_get() is just an arch friendly way to get that
I supposed (wrongly).
but yes we need to do a few things
1) seed on demand with a platform time source
Currently we use jiffies + get_cycles(). That's going to have somewhere
between, oh, 3 bits of entropy (very stable boot with only jiffies) and
25 bits of entropy (TSC with lots of waiting for hardware) at boot. Ideally, we'd have access to a wall clock of some sort as well. But
that's also a fairly limited source - wall clocks are both low
resolution and predictable/collision-prone.