Re: [libvirt] [PATCH] memtune: Add min_guarantee to the virsh tool
On Tue, 19 Oct 2010 15:49:05 +0200, Daniel Veillard <veillard(a)redhat.com> wrote:
On Tue, Oct 19, 2010 at 03:00:21PM +0200, Matthias Bolte wrote:
> 2010/10/18 Nikunj A. Dadhania <nikunj(a)linux.vnet.ibm.com>:
[...]
> > tools/virsh.c: Add new memory tunable
"min_guarantee", currently the user
> > would be ESX.
>
> Well, who said ESX could support this? :)
>
> I didn't, I just said that you added min_guarantee to libvirt, but
> didn't expose it in virsh.
Hum ... I assumed there was an use case for it.
On the other hand since it's now part of libvirt API as
VIR_DOMAIN_MEMORY_MIN_GUARANTEE enum value, it's cleaner to have it
available at the virsh level. If there is really no use (or no potential
use in a reasonable future) for it, the best is to remove it altogether
from the API and the of virsh, before next week release.
Nikunj I could not find any reference to "the well-known tunable"
min_guarantee (it's clearly not well known ...) but can you tell us
where this comes from ?
VMWare:
=======
Reservation: Gauranteed lower bound on the amount of the physical memory that
the host reserves for the VM even in case of the overcommit. The
VM is allowed to allocate till this level and after it has hit
the reservation, those pages are not reclaimed. In case, if guest
is not using till the reservation, the host can use that portion
of memory.
And maybe in future cgroups.
I would also appreciate a patch to include/libvirt/libvirt.h.in
which change the comments for VIR_DOMAIN_MEMORY_HARD_LIMIT,
VIR_DOMAIN_MEMORY_SOFT_LIMIT, VIR_DOMAIN_MEMORY_MIN_GUARANTEE,
and VIR_DOMAIN_SWAP_HARD_LIMIT relapcing the non-reference
"well known" with an actual description of what the tunable means.
We cannot keep something that vague in the header and generated
documentation,
Sure, will send a patch
Nikunj