kvm_read() vs ioctl performance

Barney Cordoba barney_cordoba at yahoo.com
Fri Mar 21 10:37:07 PDT 2008

I have an app which reads stats from the kernel
periodically, and there can be a lot of iterations,
sometimes 20,000 or more. I'm thinking of converting
from an ioctl method to kvm_read(). KVM is certainly
simpler, but its not clear what overhead is involved,
since kvm_read() likely has to call the kernel also.

Does anyone have a handle on the difference in
overhead, assuming that the ioctl call is to a module
which does nothing more than copy the data and return?



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