Mailing List Archive

[PATCH v4 0/6] mm / virtio-mem: support ZONE_MOVABLE
@Andrew can we give this a churn and consider it for v5.9 in case there
are no more comments?

Patch #1-#4,#6 have RBss or ACKs, patch #5 is virtio-mem stuff maintained
by me (and MST is aware).

---

When introducing virtio-mem, the semantics of ZONE_MOVABLE were rather
unclear, which is why we special-cased ZONE_MOVABLE such that partially
plugged blocks would never end up in ZONE_MOVABLE.

Now that the semantics are much clearer (and are documented in patch #6),
let's support partially plugged memory blocks in ZONE_MOVABLE, allowing
partially plugged memory blocks to be online to ZONE_MOVABLE and also
unplugging from such memory blocks. This avoids surprises when onlining
of memory blocks suddenly fails, just because they are not completely
populated by virtio-mem (yet).

This is especially helpful for testing, but also paves the way for
virtio-mem optimizations, allowing more memory to get reliably unplugged.

Cleanup has_unmovable_pages() and set_migratetype_isolate(), providing
better documentation of how ZONE_MOVABLE interacts with different kind of
unmovable pages (memory offlining vs. alloc_contig_range()).

v3 -> v4:
- "mm/page_isolation: drop WARN_ON_ONCE() in set_migratetype_isolate()"
-- Fix typo in description
- "virtio-mem: don't special-case ZONE_MOVABLE"
-- Add more details why we initialli special-cased ZONE_MOVABLE (via MST)
- "mm: document semantics of ZONE_MOVABLE"
-- Rephrase some parts of documentation (via Mike)

v2 -> v3:
- "mm: document semantics of ZONE_MOVABLE"
-- Fix a typo

v1 -> v2:
- "mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()"
-- Move to position 1, add Fixes: tag
-- Drop unused "out:" label
- "mm/page_isolation: drop WARN_ON_ONCE() in set_migratetype_isolate()"
-- Keep curly braces on "else" case
- Replace "[PATCH v1 5/6] mm/page_alloc: restrict ZONE_MOVABLE optimization
in has_unmovable_pages() to memory offlining"
by "mm: document semantics of ZONE_MOVABLE"
-- Brain dump of what I know about ZONE_MOVABLE

David Hildenbrand (6):
mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()
mm/page_alloc: tweak comments in has_unmovable_pages()
mm/page_isolation: drop WARN_ON_ONCE() in set_migratetype_isolate()
mm/page_isolation: cleanup set_migratetype_isolate()
virtio-mem: don't special-case ZONE_MOVABLE
mm: document semantics of ZONE_MOVABLE

drivers/virtio/virtio_mem.c | 47 +++++++------------------------------
include/linux/mmzone.h | 35 +++++++++++++++++++++++++++
mm/page_alloc.c | 22 +++++------------
mm/page_isolation.c | 39 ++++++++++++++----------------
4 files changed, 66 insertions(+), 77 deletions(-)

--
2.26.2
Re: [PATCH v4 0/6] mm / virtio-mem: support ZONE_MOVABLE [ In reply to ]
On 04.08.20 21:41, David Hildenbrand wrote:
> @Andrew can we give this a churn and consider it for v5.9 in case there
> are no more comments?

@Andrew, Ping, so I assume we'll target v5.10?


>
> Patch #1-#4,#6 have RBss or ACKs, patch #5 is virtio-mem stuff maintained
> by me (and MST is aware).
>
> ---
>
> When introducing virtio-mem, the semantics of ZONE_MOVABLE were rather
> unclear, which is why we special-cased ZONE_MOVABLE such that partially
> plugged blocks would never end up in ZONE_MOVABLE.
>
> Now that the semantics are much clearer (and are documented in patch #6),
> let's support partially plugged memory blocks in ZONE_MOVABLE, allowing
> partially plugged memory blocks to be online to ZONE_MOVABLE and also
> unplugging from such memory blocks. This avoids surprises when onlining
> of memory blocks suddenly fails, just because they are not completely
> populated by virtio-mem (yet).
>
> This is especially helpful for testing, but also paves the way for
> virtio-mem optimizations, allowing more memory to get reliably unplugged.
>
> Cleanup has_unmovable_pages() and set_migratetype_isolate(), providing
> better documentation of how ZONE_MOVABLE interacts with different kind of
> unmovable pages (memory offlining vs. alloc_contig_range()).
>
> v3 -> v4:
> - "mm/page_isolation: drop WARN_ON_ONCE() in set_migratetype_isolate()"
> -- Fix typo in description
> - "virtio-mem: don't special-case ZONE_MOVABLE"
> -- Add more details why we initialli special-cased ZONE_MOVABLE (via MST)
> - "mm: document semantics of ZONE_MOVABLE"
> -- Rephrase some parts of documentation (via Mike)
>
> v2 -> v3:
> - "mm: document semantics of ZONE_MOVABLE"
> -- Fix a typo
>
> v1 -> v2:
> - "mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()"
> -- Move to position 1, add Fixes: tag
> -- Drop unused "out:" label
> - "mm/page_isolation: drop WARN_ON_ONCE() in set_migratetype_isolate()"
> -- Keep curly braces on "else" case
> - Replace "[PATCH v1 5/6] mm/page_alloc: restrict ZONE_MOVABLE optimization
> in has_unmovable_pages() to memory offlining"
> by "mm: document semantics of ZONE_MOVABLE"
> -- Brain dump of what I know about ZONE_MOVABLE
>
> David Hildenbrand (6):
> mm/page_isolation: don't dump_page(NULL) in set_migratetype_isolate()
> mm/page_alloc: tweak comments in has_unmovable_pages()
> mm/page_isolation: drop WARN_ON_ONCE() in set_migratetype_isolate()
> mm/page_isolation: cleanup set_migratetype_isolate()
> virtio-mem: don't special-case ZONE_MOVABLE
> mm: document semantics of ZONE_MOVABLE
>
> drivers/virtio/virtio_mem.c | 47 +++++++------------------------------
> include/linux/mmzone.h | 35 +++++++++++++++++++++++++++
> mm/page_alloc.c | 22 +++++------------
> mm/page_isolation.c | 39 ++++++++++++++----------------
> 4 files changed, 66 insertions(+), 77 deletions(-)
>


--
Thanks,

David / dhildenb
Re: [PATCH v4 0/6] mm / virtio-mem: support ZONE_MOVABLE [ In reply to ]
On Mon, 10 Aug 2020 09:56:32 +0200 David Hildenbrand <david@redhat.com> wrote:

> On 04.08.20 21:41, David Hildenbrand wrote:
> > @Andrew can we give this a churn and consider it for v5.9 in case there
> > are no more comments?
>
> @Andrew, Ping, so I assume we'll target v5.10?

Yep, sorry. Merging a significant patch series during the merge
window(!) would be quite extraordinary and I don't think that anything
in this patchset justifies such an action?
Re: [PATCH v4 0/6] mm / virtio-mem: support ZONE_MOVABLE [ In reply to ]
On 11.08.20 04:21, Andrew Morton wrote:
> On Mon, 10 Aug 2020 09:56:32 +0200 David Hildenbrand <david@redhat.com> wrote:
>
>> On 04.08.20 21:41, David Hildenbrand wrote:
>>> @Andrew can we give this a churn and consider it for v5.9 in case there
>>> are no more comments?
>>
>> @Andrew, Ping, so I assume we'll target v5.10?
>
> Yep, sorry. Merging a significant patch series during the merge
> window(!) would be quite extraordinary and I don't think that anything
> in this patchset justifies such an action?
>

Okay, now I know you are aware of this series :)

First, I thought #1 would be worth for v5.9, but it looks like it's not
actually necessary. I'll respin the whole series for v5.10.

--
Thanks,

David / dhildenb