Re: RFC: A reduced Linux network stack for small systems

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that is likely working only for the given very limited set of applications.
Kernel function profiling can potentially achieve the same thing.
Profile the kernel with the set of apps and then prune all cold
functions out of kernel.

Right, and are Profile-Guided-Optimization results now reproduceable?
Better change it to Trace-Guided-Optimization.  But yeah, for a

not quite. I'm saying: no extra optimizations, no GCC changes.
Compile kernel as-is. Most functions have a stub for mcount() already.
Use it to track whether kernel function was called or not.
Collect this data in userspace (as perf already does), add few
more functions that had 'notrace' attribute on them, and feed this into
special linker that unpacks existing vmlinux, throws away cold functions,
relocates the rest and here you have tiny vmlinux without recompilation.

It sounds like unstripped kernel will not even fit on the target machine.
If it+application would fit there, you'd have no reason to strip it down...

									Pavel

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