kernel/linux.git/mm/balloon_compaction.c, branch v6.12.91

mm/balloon_compaction: convert balloon_page_delete() to balloon_page_finalize()

2026-01-08T09:15:05+00:00

[ Upstream commit 15504b1163007bbfbd9a63460d5c14737c16e96d ] Let's move the removal of the page from the balloon list into the single caller, to remove the dependency on the PG_isolated flag and clarify locking requirements. Note that for now, balloon_page_delete() was used on two paths: (1) Removing a page from the balloon for deflation through balloon_page_list_dequeue() (2) Removing an isolated page from the balloon for migration in the per-driver migration handlers. Isolated pages were already removed from the balloon list during isolation. So instead of relying on the flag, we can just distinguish both cases directly and handle it accordingly in the caller. We'll shuffle the operations a bit such that they logically make more sense (e.g., remove from the list before clearing flags). In balloon migration functions we can now move the balloon_page_finalize() out of the balloon lock and perform the finalization just before dropping the balloon reference. Document that the page lock is currently required when modifying the movability aspects of a page; hopefully we can soon decouple this from the page lock. Link: https://lkml.kernel.org/r/20250704102524.326966-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Brendan Jackman Cc: Byungchul Park Cc: Chengming Zhou Cc: Christian Brauner Cc: Christophe Leroy Cc: Eugenio Pé rez Cc: Greg Kroah-Hartman Cc: Gregory Price Cc: Harry Yoo Cc: "Huang, Ying" Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Wang Cc: Jerrin Shaji George Cc: Johannes Weiner Cc: John Hubbard Cc: Jonathan Corbet Cc: Joshua Hahn Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Michal Hocko Cc: Mike Rapoport Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Peter Xu Cc: Qi Zheng Cc: Rakie Kim Cc: Rik van Riel Cc: Sergey Senozhatsky Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: xu xin Cc: Zi Yan Signed-off-by: Andrew Morton Stable-dep-of: 0da2ba35c0d5 ("powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

mm/balloon_compaction: we cannot have isolated pages in the balloon list

2026-01-08T09:15:05+00:00

[ Upstream commit fb05f992b6bbb4702307d96f00703ee637b24dbf ] Patch series "mm/migration: rework movable_ops page migration (part 1)", v2. In the future, as we decouple "struct page" from "struct folio", pages that support "non-lru page migration" -- movable_ops page migration such as memory balloons and zsmalloc -- will no longer be folios. They will not have ->mapping, ->lru, and likely no refcount and no page lock. But they will have a type and flags 🙂 This is the first part (other parts not written yet) of decoupling movable_ops page migration from folio migration. In this series, we get rid of the ->mapping usage, and start cleaning up the code + separating it from folio migration. Migration core will have to be further reworked to not treat movable_ops pages like folios. This is the first step into that direction. This patch (of 29): The core will set PG_isolated only after mops->isolate_page() was called. In case of the balloon, that is where we will remove it from the balloon list. So we cannot have isolated pages in the balloon list. Let's drop this unnecessary check. Link: https://lkml.kernel.org/r/20250704102524.326966-2-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Zi Yan Reviewed-by: Lorenzo Stoakes Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Brendan Jackman Cc: Byungchul Park Cc: Chengming Zhou Cc: Christian Brauner Cc: Christophe Leroy Cc: Eugenio Pé rez Cc: Greg Kroah-Hartman Cc: Gregory Price Cc: "Huang, Ying" Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Wang Cc: Jerrin Shaji George Cc: Johannes Weiner Cc: John Hubbard Cc: Jonathan Corbet Cc: Joshua Hahn Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Michal Hocko Cc: Mike Rapoport Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Peter Xu Cc: Qi Zheng Cc: Rakie Kim Cc: Rik van Riel Cc: Sergey Senozhatsky Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: xu xin Cc: Harry Yoo Signed-off-by: Andrew Morton Stable-dep-of: 0da2ba35c0d5 ("powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

mm: remove MIGRATE_SYNC_NO_COPY mode

2024-07-04T02:30:00+00:00

Commit 2916ecc0f9d4 ("mm/migrate: new migrate mode MIGRATE_SYNC_NO_COPY") introduce a new MIGRATE_SYNC_NO_COPY mode to allow to offload the copy to a device DMA engine, which is only used __migrate_device_pages() to decide whether or not copy the old page, and the MIGRATE_SYNC_NO_COPY mode only set in hmm, as the MIGRATE_SYNC_NO_COPY set is removed by previous cleanup, it seems that we could remove the unnecessary MIGRATE_SYNC_NO_COPY. Link: https://lkml.kernel.org/r/20240524052843.182275-6-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Reviewed-by: Jane Chu Cc: Alistair Popple Cc: Benjamin LaHaise Cc: David Hildenbrand Cc: Hugh Dickins Cc: Jérôme Glisse Cc: Jiaqi Yan Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Muchun Song Cc: Naoya Horiguchi Cc: Tony Luck Cc: Vishal Moola (Oracle) Cc: Zi Yan Signed-off-by: Andrew Morton

mm: Convert all PageMovable users to movable_operations

2022-08-02T16:34:03+00:00

These drivers are rather uncomfortably hammered into the address_space_operations hole. They aren't filesystems and don't behave like filesystems. They just need their own movable_operations structure, which we can point to directly from page->mapping. Signed-off-by: Matthew Wilcox (Oracle)

mm/balloon_compaction: make balloon page compaction callbacks static

2022-03-28T20:52:57+00:00

Since commit b1123ea6d3b3 ("mm: balloon: use general non-lru movable page feature"), these functions are called via balloon_aops callbacks. They're not called directly outside this file. So make them static and clean up the relevant code. Signed-off-by: Miaohe Lin Link: https://lore.kernel.org/r/20220125132221.2220-1-linmiaohe@huawei.com Signed-off-by: Michael S. Tsirkin Reviewed-by: Muchun Song

mm: fix typos in comments

2021-05-07T07:26:35+00:00

Fix ~94 single-word typos in locking code comments, plus a few very obvious grammar mistakes. Link: https://lkml.kernel.org/r/20210322212624.GA1963421@gmail.com Link: https://lore.kernel.org/r/20210322205203.GB1959563@gmail.com Signed-off-by: Ingo Molnar Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Randy Dunlap Cc: Bhaskar Chowdhury Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/balloon_compaction: suppress allocation warnings

2019-09-04T11:42:01+00:00

There is no reason to print warnings when balloon page allocation fails, as they are expected and can be handled gracefully. Since VMware balloon now uses balloon-compaction infrastructure, and suppressed these warnings before, it is also beneficial to suppress these warnings to keep the same behavior that the balloon had before. Cc: Jason Wang Signed-off-by: Nadav Amit Signed-off-by: Michael S. Tsirkin Reviewed-by: David Hildenbrand

balloon: fix up comments

2019-07-22T15:19:26+00:00

Lots of comments bitrotted. Fix them up. Fixes: 418a3ab1e778 (mm/balloon_compaction: List interfaces) Reviewed-by: Wei Wang Signed-off-by: Michael S. Tsirkin Reviewed-by: Ralph Campbell Acked-by: Nadav Amit

mm/balloon_compaction: avoid duplicate page removal

2019-07-22T15:19:26+00:00

A #GP is reported in the guest when requesting balloon inflation via virtio-balloon. The reason is that the virtio-balloon driver has removed the page from its internal page list (via balloon_page_pop), but balloon_page_enqueue_one also calls "list_del" to do the removal. This is necessary when it's used from balloon_page_enqueue_list, but not from balloon_page_enqueue. Move list_del to balloon_page_enqueue, and update comments accordingly. Fixes: 418a3ab1e778 (mm/balloon_compaction: List interfaces) Signed-off-by: Wei Wang Signed-off-by: Michael S. Tsirkin

Merge 5.2-rc4 into char-misc-next

2019-06-09T07:11:21+00:00

We want the char/misc driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman