[Jonathan S Shapiro]
On Thu, 2005-02-24 at 09:15 +0100, Ronald Aigner wrote:
I disagree with the opinion that the complexity of a microkernel should be measured by the number of its system-calls. I find it rather complex to multiplex dozen flavours of IPC via one systemcall.
I am not sure quite what motivated this comment. We have argued in the EROS design that having exactly one system call ("invoke capability", in our case) is good, but not because it reduces microkernel complexity -- in fact, it complicates it.
Would also like to add that the reason for multiplexing all these operations in the IPC mechanism is not really to reduce complexity. We multiplex all these operations because the operations are similar enough in nature to share the same codepath and thereby reduce the cache/memory footprint of the kernel.
I don't think anyone has ever stated that the number of system calls is a measure for the *complexity* of the kernel.
eSk