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Alan Cox wrote: > On Tue, 2002-12-17 at 19:26, Martin J. Bligh wrote: > >>>>It's not as good as a pure user-mode solution using tsc could be, but >> >>You can't use the TSC to do gettimeofday on boxes where they aren't >>syncronised anyway though. That's nothing to do with vsyscalls, you just >>need a different time source (eg the legacy stuff or HPET/cyclone). > > > Ditto all the laptops and the like. With code provided by the kernel we > can cheat however. If we know the fastest the CPU can go (ie full speed > on spudstop/powernow etc) we can tell the tsc value at which we have to > query the kernel to get time to any given accuracy, so allowing limited > caching > > Ditto by knowing the worst case drift on summit > Clever. I like it :) -hpa - 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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