Re: successful GUB build on my LilyDev (2.6)

[James]

John,

On 28 August 2012 15:31, John Mandereau <address@hidden> wrote:
> 2012/8/28 Phil Holmes <address@hidden>:
>> Yes - "it" is Gub.  I might try getting it working on 64 bit once I've
>> bedded down regularly running it in the VM.
>
> Running GUB inside a VM must slow it down a lot,

It depends. If you have V-T enabled CPUs on your PC and the Virtual
Software (VirtualBox or linux's qemu-KVM in the 3.x kernels for
example) is able to access the CPUs directly because of that -
effectively the OS in the VM has direct access to the CPU as if it
were installed on bare metal. There is 'some' loss but it's negligible
on my system - I seem to recall about 120 second difference compiling
native vs in a VM. SSDs do also help.

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

Para-virtualization will slow things down but I don't have any
figures, but even they are getting better.

You may then ask why bother using a VM at all and just install and
compile on your own OS. It's easy then to roll out cloned VMs or take
snapshots and roll back to certain points - I used to use this a lot
before we had patchy test scripts - I'd run make and make
test-baseline, take a snapshot and the apply a patch and run make
test. When that was done, roll back to the snapshot and apply next
patch and run make ; make test without the need to do another make
test-baseline. Took seconds to roll back, saved me 10 minutes a patch
(and that's on a fast machine) and I could guarantee a clean make test
each time.

i am sure there are other methods that snapshots can be used for, as
long as you have the disk space and reasonable amounts of RAM, I think
it's a nice way to develop.

Oh and it helps when testing new LilyDevs.

James