Messages in this thread | | | From | Nicholas Tsirakis <> | Date | Thu, 12 Dec 2019 09:30:23 -0500 | Subject | Re: [BUG] Xen-ballooned memory never returned to domain after partial-free |
| |
>> Do you happen to know the answer to my second question? It's not as important, >> but it does confuse me as I wouldn't expect the total memory to be >> balloon-able at >> all with the hotplugging configs disabled.
> Ballooning != hotplugging memory > > With memory hotplug you can add (or - in theory - remove) memory to the > kernel it didn't know about before. > > With ballooning you just give some memory back to the hypervisor, but > kernel still has some knowledge about it (e.g. keeps struct page for > each ballooned memory page).
Got it, thanks for that clarification and for all your help!
--Niko
On Thu, Dec 12, 2019 at 9:21 AM Jürgen Groß <jgross@suse.com> wrote: > > On 12.12.19 15:10, Nicholas Tsirakis wrote: > >> And I think this is the problem. We want here: > >> > >> balloon_stats.target_pages = balloon_stats.current_pages + > >> balloon_stats.target_unpopulated; > > > > Ahh I knew I was missing something. Tested the patch, works great! "Reported by" > > is fine with me. > > Thanks. > > > > > Do you happen to know the answer to my second question? It's not as important, > > but it does confuse me as I wouldn't expect the total memory to be > > balloon-able at > > all with the hotplugging configs disabled. > > Ballooning != hotplugging memory > > With memory hotplug you can add (or - in theory - remove) memory to the > kernel it didn't know about before. > > With ballooning you just give some memory back to the hypervisor, but > kernel still has some knowledge about it (e.g. keeps struct page for > each ballooned memory page). > > HTH, Juergen
| |