Re: [RTnet-users] System-freeze while using rttcp and rtudp in parallel

[Gilles C. <gil...@xe...>]

On Sun, Jun 28, 2015 at 04:24:42PM +0200, Jan Kiszka wrote:
> - transfer of setup into QEMU/KVM, then using built-in gdbstub
>   (works like a hardware debugger, just cheaper and faster)

You can't be faster than a JTAG debugger. With a JTAG debugger,
the processor runs at full speed, with QEMU, even with KVM it does
not, because some things are still emulated. For instance, if your
processor does not support what is called "extended page tables",
the job of handling the MMU page tables is emulated in the qemu
host, and that hurts. If you look at the second column of the list
on intel website:

http://ark.intel.com/Products/VirtualizationTechnology

You will see that even though all core i* processors support EPT,
older processors do not, and very few Atom processors do.

By contrast, even the lowest end processor that supports JTAG (and I
have never met one which did not) does not need to emulate its MMU
when running in a debugger.

-- 
					    Gilles.
https://click-hack.org