Messages in this thread | | | Date | Mon, 12 Dec 2011 11:02:36 +0000 | From | Alan Cox <> | Subject | Re: [patch 0/3] kvm tool: Serial emulation overhaul |
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> > You can emulate a chip with a 64byte or so FIFO. You can do I/O cycle > > prediction in the kernel part and you can use the empty bit as a clue > > (which is what most serial<->ethernet widgetry does). > > The performance problems here aren't the same performance problems you > have on real hardware. The problem here is that it costs 40k cycles for > the guest to access the emulated chip.
How much of that 40K cycles is bouncing back and forth into emulation layers and how much of it is the kernel trap ?
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