Linux: Reviewing the Tickless Kernel for x86-64

“Included in Andrew Morton’s potential 2.6.23 merge list were a
series of patches to make the x86-64 architecture tickless. Andi
Kleen, the x86-64 maintainer replied, ‘I’m sceptical about the
dynticks code. It just rips out the x86-64 timing code completely,
which needs a lot more review and testing. Probably not .23.’ Linus
Torvalds agreed, ‘we are *not* going to do another ‘rip everything
out, and replace it with new code’ again. Over my dead body. We’re
going to do this thing gradually, or not at all.’ He went on to
explain ‘the patch-set itself actually looks fine, as far as I’m
concerned. But it does seem to have that ‘enable everything in one
go’ problem. I’d much rather see one time source at a time being
converted, and enabled then and there, so that when people report
problems and do a bisection, if it was HPET that broke, you get the
commit that changed HPET…'”

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