On Wed, Oct 31, 2018 at 05:07
PM +0200, Roger Pau Monné
wrote:
> On
Wed, Oct 31, 2018 at 04:38:08PM +0200, Alexandru Vasile wrote:
> >
Hello,
> >
>
>
> > I
am writing as a follow up from our discussion on the xen-devel
mailing
> > list
[0].
> >
>
> You mentioned some ‘low-hanging fruit, both in Xen and
the Linux kernel’ and
> > if
I am ever interested to talk about sharing the workload.
> >
>
> Could you share more details about this?
> -
Xen: make sure PVH Dom0 works without the dom0_mem parameter.
There
>
have been reports that the initial memory accounting for Xen and
>
Dom0 is bogus for a PVH Dom0 depending on the host amount of RAM
>
and other factors. This will involve testing PVH Dom0 on several
>
boxes without the dom0_mem parameter and coming up with a better
>
algorithm to calculate the amount of memory required by Xen and
>
Dom0. Changes will be mostly limited to the
dom0_compute_nr_pages
>
and dom0_paging_pages functions I expect.
>
- Linux: there are issues in the way Linux maps foreign memory
and
>
grants when running in PVH mode. AFAIK Linux will balloon out
RAM
>
and use the freed range in order to map foreign memory or
grants.
>
This can cause out of memory issues if there are enough
mappings,
>
and also decreases the RAM available to Dom0 for no reason.
>
Solving this issue requires an analysis of the problem and
drafting
>
a document that describes the solution before implementing
it, as
>
it's slightly tricky. This document would be sent to xen-devel
for
>
review and opinions.
[0]
https://lists.xenproject.org/archives/html/xen-devel/2018-10/msg01580.html
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