Messages in this thread | | | Date | Tue, 10 Sep 2013 16:38:53 -0400 | From | Theodore Ts'o <> | Subject | Re: [PATCH] /dev/random: Insufficient of entropy on many architectures |
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On Tue, Sep 10, 2013 at 12:38:56PM -0700, John Stultz wrote: > So the end of timekeeping_init() may not be what you want here. This > only means we've started up the timekeping core with only the default > clocksource (with only few exceptions, this is almost always jiffies). > Then as clocksource drivers are initialized, they are registered and > the timekeeping core will switch over to the best available > clocksource. Also, to avoid the churn at boot of switching to every > clocksource registered, we queue them up and wait until fs_init time > to switch to whatever is the best available then.
Is there any indication in the clocksource structures where we can determine what the cost (in CPU, time, bus overhead, etc.) for a particular clock source, verus the granularity of the clock source?
Also, is it always safe to read from a clock source from an interrupt handler?
Thanks,
- Ted
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