Re: Warning about kernel 4.2 performance (revised)

Hi Bart,
> At least on Westmere+ CPUs (first gen Core i3/i5/i7) KVM can run
> "unrestricted guest" mode which behaves like real mode and seems just
> as fast as vm86() but it traps less than vm86 so some things that
> dosemu depends upon (e.g. that INTs are trapped) do not work. That can
> be worked around though with some more coding.

In our case the ability to get hardware interrupts routed through to the 
DOS emulator's code in a prompt manner is VERY important. In fact that 
is one major reason we have generally not played with the 64-bit version 
very much in the past.

By "prompt" I mean less than 10us or so which was no trouble in the 
native 286/DOS era, and today should not be a problem given a typical 
CPU can execute some 30k instructions in that time, but we know that is 
not how software bloat and indirection go :(

Regards,
Paul