Messages in this thread | | | Subject | Re: [PATCH 01/10] random: make 'add_interrupt_randomness()' do something sane | From | Matt Mackall <> | Date | Thu, 05 Jul 2012 17:31:22 -0500 |
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On Thu, 2012-07-05 at 15:21 -0700, Linus Torvalds wrote: > On Thu, Jul 5, 2012 at 3:00 PM, Theodore Ts'o <tytso@mit.edu> wrote: > > > > Like this? > > Looks fine to me. > > Although I think it might be better to stay closer to what we used to > do, and just 'or' in the action flags rather than make it some > conditional. And then at the end, do > > if (!(flags & __IRQF_TIMER)) > add_interrupt_randomness(irq)
On systems with a timer interrupt and a sched_clock() that's asynchronous to it, this actually loses a great source of entropy for headless systems. Also: extra branch in fast path.
It's better to mix and not credit than to not mix at all. Instead just check the fast count against HZ before the credit.
-- Mathematics is the supreme nostalgia of our time.
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