On Thu, 2007-06-21 at 22:57 +0200, Sergio Ruocco wrote:
My question is:
As far as I know, Fiasco is entirely preemptable. Then why sprinkling the IPC path with Enable IRQs/NOP NOP/Disable IRQs ?
Is there a document or a paper that discuss which parts of the kernel run with IRQs disabled / enabled ? Preemption disabled / enabled etc. ?
In particular, the Fiasco IPC path for register only IPC runs with disabled interrupts and has explicit preemption points. The work of Rene Reusner (unfortunately in German) describes the trade-off between preemptability and performance of the IPC path.
http://os.inf.tu-dresden.de/papers_ps/reusner-diplom.pdf