Displaying 5 results from an estimated 5 matches for "pfn_to_online_page".
2019 Oct 18
0
[PATCH RFC v3 6/9] mm: Allow to offline PageOffline() pages with a reference count of 0
...'t like releasing "pages that should not be used" to the buddy. It
comes with some problems if offlining fails (see below).
>
> Let's say that you still keep a reference to your offlined pages and
> mark them offlined. That should make sure that no consumer of the
> pfn_to_online_page will touch the page's content nor the state. Now
pfn_to_online_page() does not check against PG_offline. (which is
correct IMHO. As documented, PG_offline means "logically offline".
The memmap is valid, however the page content should not be accessed.
(PG_logically_offline would h...
2019 Oct 18
2
[PATCH RFC v3 6/9] mm: Allow to offline PageOffline() pages with a reference count of 0
...r will not
magically appear after onlining. But I believe that you can achieve
the same with an elevated reference count and have a more robust design
as well.
Let's say that you still keep a reference to your offlined pages and
mark them offlined. That should make sure that no consumer of the
pfn_to_online_page will touch the page's content nor the state. Now
admin might want to offline/hotremove the whole memory block via sysfs.
An elevated reference count would prevent offlining to finish. And I
believe this is a good thing because the owner of the offline page might
still need to do something to &q...
2019 Oct 18
2
[PATCH RFC v3 6/9] mm: Allow to offline PageOffline() pages with a reference count of 0
...r will not
magically appear after onlining. But I believe that you can achieve
the same with an elevated reference count and have a more robust design
as well.
Let's say that you still keep a reference to your offlined pages and
mark them offlined. That should make sure that no consumer of the
pfn_to_online_page will touch the page's content nor the state. Now
admin might want to offline/hotremove the whole memory block via sysfs.
An elevated reference count would prevent offlining to finish. And I
believe this is a good thing because the owner of the offline page might
still need to do something to &q...
2019 Oct 16
2
[PATCH RFC v3 6/9] mm: Allow to offline PageOffline() pages with a reference count of 0
On Wed 16-10-19 15:45:06, David Hildenbrand wrote:
> On 16.10.19 13:43, Michal Hocko wrote:
> > On Thu 19-09-19 16:22:25, David Hildenbrand wrote:
> > > virtio-mem wants to allow to offline memory blocks of which some parts
> > > were unplugged, especially, to later offline and remove completely
> > > unplugged memory blocks. The important part is that
2019 Oct 16
2
[PATCH RFC v3 6/9] mm: Allow to offline PageOffline() pages with a reference count of 0
On Wed 16-10-19 15:45:06, David Hildenbrand wrote:
> On 16.10.19 13:43, Michal Hocko wrote:
> > On Thu 19-09-19 16:22:25, David Hildenbrand wrote:
> > > virtio-mem wants to allow to offline memory blocks of which some parts
> > > were unplugged, especially, to later offline and remove completely
> > > unplugged memory blocks. The important part is that