| Date | Thu, 5 Jul 2012 15:47:42 -0400 | From | Theodore Ts'o <> | Subject | Re: [PATCH 02/10] random: use lockless techniques when mixing entropy pools |
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On Thu, Jul 05, 2012 at 02:10:12PM -0500, Matt Mackall wrote: > > I don't think this will work correctly. It's important that simultaneous > _readers_ of the state get different results. Otherwise, you can get > things like duplicate UUIDs generated on different cores, something > that's been observed in the field(!). I thought I added a comment to > that effect some years back, but I guess not.
That's easy to fix; we just need to take a spinlock on the extract side. The main issue is that Thomas very much doesn't want us to take a spinlock in the interrupt handler codepath. But if we take a spinlock while extracting, that should take care of this concern.
- Ted
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