lkml.org 
[lkml]   [2019]   [Apr]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Thoughts on simple scanner approach for free page hinting
On Tue, Apr 09, 2019 at 03:36:08PM +0200, David Hildenbrand wrote:
> On 09.04.19 15:31, Michael S. Tsirkin wrote:
> > On Tue, Apr 09, 2019 at 11:20:36AM +0200, David Hildenbrand wrote:
> >> BTW I like the idea of allocating pages that have already been hinted as
> >> last "choice", allocating pages that have not been hinted yet first.
> >
> > OK I guess but note this is just a small window during which
> > not all pages have been hinted.
>
> Yes, good point. It might sound desirable but might be completely
> irrelevant in practice.
>
> >
> > So if we actually think this has value then we need
> > to design something that will desist and not drop pages
> > in steady state too.
>
> By dropping, you mean dropping hints of e.g. MAX_ORDER - 1 or e.g. not
> reporting MAX_ORDER - 3?

I mean the issue is host unmaps the pages from guest right? That is
what makes hinted pages slower than non-hinted ones. If we do not want
that to happen for some pages, then either host can defer acting on the
hint, or we can defer hinting.

> --
>
> Thanks,
>
> David / dhildenb

\
 
 \ /
  Last update: 2019-04-09 15:39    [W:0.064 / U:0.540 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site