[Arm-dev] Gigabyte MP30-AR0

[Richard W.M. Jones]

On Tue, Mar 15, 2016 at 07:49:22PM +0000, Gordan Bobic wrote:
> On 2016-03-15 18:32, Richard W.M. Jones wrote:
> >I may be missing some context here, but is there some reason not to
> >just use a VM?
> 
> Performance for one.

Can you precisely quantify that?

> >It's more predictable because you'll be running the
> >same kernel that the 32 bit environment is expecting.
> 
> The aarch64 environment seems no less predictable with a
> kernel defaulting to 4K pages.

It's more predictable for the 32 bit guest, because the guest will
have exactly the kernel it expects, not some random kernel and a
chroot.

> There are also other reasons, for example I want to run ZFS on the
> host and don't want to have to re-export the shares to guests via a
> network file system.

> > Also it will
> > (or should) work without you needing to compile your own host kernel.
> 
> Well, as far as the host kernel is concerned:
> 
> 1) I already posted a link with a selection of posts from Linus himself
> explaining at some length why using large default pages is a bad idea
> at the best of times (and for all other cases where bigger pages do give
> us that 3% speed-up we can use hugepages directly instead).
>
> 2) The kernel that ships is deprecated and was never a LT kernel (4.2).
> 
> So switching to the next LT kernel better configured for practically
> any task seems advantageous in every way.

I think RHELSA 7.3 will have a 4.5 kernel.  Of course "LT" kernels
aren't really relevant for Red Hat, because we spend huge amounts of
money supporting our kernels long term.

> I now have docker happily running armv5tel guests.

Rich.

-- 
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