user/sven/linux.git/include/linux/rmap.h, branch v6.9.9

mm/rmap: silence VM_WARN_ON_FOLIO() in __folio_rmap_sanity_checks()

2024-01-05T18:17:43Z

Unfortunately, vm_insert_page() and friends and up passing driver-allocated folios into folio_add_file_rmap_pte() using insert_page_into_pte_locked(). While these driver-allocated folios can be compound pages (large folios), they are not proper "rmappable" folios. In these VM_MIXEDMAP VMAs, there isn't really the concept of a reverse mapping, so long-term, we should clean that up and not call into rmap code. For the time being, document how we can end up in rmap code with large folios that are not marked rmappable. Link: https://lkml.kernel.org/r/793c5cee-d5fc-4eb1-86a2-39e05686233d@redhat.com Fixes: 68f0320824fa ("mm/rmap: convert folio_add_file_rmap_range() into folio_add_file_rmap_[pte|ptes|pmd]()") Reported-by: syzbot+50ef73537bbc393a25bb@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/000000000000014174060e09316e@google.com Signed-off-by: David Hildenbrand Cc: Matthew Wilcox (Oracle) Cc: Ryan Roberts Cc: Yin Fengwei Signed-off-by: Andrew Morton

mm: convert page_try_share_anon_rmap() to folio_try_share_anon_rmap_[pte|pmd]()

2023-12-29T19:58:56Z

Let's convert it like we converted all the other rmap functions. Don't introduce folio_try_share_anon_rmap_ptes() for now, as we don't have a user that wants rmap batching in sight. Pretty easy to add later. All users are easy to convert -- only ksm.c doesn't use folios yet but that is left for future work -- so let's just do it in a single shot. While at it, turn the BUG_ON into a WARN_ON_ONCE. Note that page_try_share_anon_rmap() so far didn't care about pte/pmd mappings (no compound parameter). We're changing that so we can perform better sanity checks and make the code actually more readable/consistent. For example, __folio_rmap_sanity_checks() will make sure that a PMD range actually falls completely into the folio. Link: https://lkml.kernel.org/r/20231220224504.646757-39-david@redhat.com Signed-off-by: David Hildenbrand Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Muchun Song Cc: Peter Xu Cc: Ryan Roberts Cc: Yin Fengwei Signed-off-by: Andrew Morton

mm/rmap: remove page_try_dup_anon_rmap()

2023-12-29T19:58:56Z

All users are gone, remove page_try_dup_anon_rmap() and any remaining traces. Link: https://lkml.kernel.org/r/20231220224504.646757-38-david@redhat.com Signed-off-by: David Hildenbrand Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Muchun Song Cc: Peter Xu Cc: Ryan Roberts Cc: Yin Fengwei Signed-off-by: Andrew Morton

mm/rmap: introduce folio_try_dup_anon_rmap_[pte|ptes|pmd]()

2023-12-29T19:58:55Z

The last user of page_needs_cow_for_dma() and __page_dup_rmap() are gone, remove them. Add folio_try_dup_anon_rmap_ptes() right away, we want to perform rmap baching during fork() soon. Link: https://lkml.kernel.org/r/20231220224504.646757-35-david@redhat.com Signed-off-by: David Hildenbrand Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Muchun Song Cc: Peter Xu Cc: Ryan Roberts Cc: Yin Fengwei Signed-off-by: Andrew Morton

mm/rmap: convert page_dup_file_rmap() to folio_dup_file_rmap_[pte|ptes|pmd]()

2023-12-29T19:58:55Z

Let's convert page_dup_file_rmap() like the other rmap functions. As there is only a single caller, convert that single caller right away and remove page_dup_file_rmap(). Add folio_dup_file_rmap_ptes() right away, we want to perform rmap baching during fork() soon. Link: https://lkml.kernel.org/r/20231220224504.646757-34-david@redhat.com Signed-off-by: David Hildenbrand Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Muchun Song Cc: Peter Xu Cc: Ryan Roberts Cc: Yin Fengwei Signed-off-by: Andrew Morton

mm/rmap: remove page_remove_rmap()

2023-12-29T19:58:55Z

All callers are gone, let's remove it and some leftover traces. Link: https://lkml.kernel.org/r/20231220224504.646757-33-david@redhat.com Signed-off-by: David Hildenbrand Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Muchun Song Cc: Peter Xu Cc: Ryan Roberts Cc: Yin Fengwei Signed-off-by: Andrew Morton

mm/rmap: introduce folio_remove_rmap_[pte|ptes|pmd]()

2023-12-29T19:58:52Z

Let's mimic what we did with folio_add_file_rmap_*() and folio_add_anon_rmap_*() so we can similarly replace page_remove_rmap() next. Make the compiler always special-case on the granularity by using __always_inline. We're adding folio_remove_rmap_ptes() handling right away, as we want to use that soon for batching rmap operations when unmapping PTE-mapped large folios. Link: https://lkml.kernel.org/r/20231220224504.646757-24-david@redhat.com Signed-off-by: David Hildenbrand Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Muchun Song Cc: Peter Xu Cc: Ryan Roberts Cc: Yin Fengwei Signed-off-by: Andrew Morton

mm/rmap: remove RMAP_COMPOUND

2023-12-29T19:58:52Z

No longer used, let's remove it and clarify RMAP_NONE/RMAP_EXCLUSIVE a bit. Link: https://lkml.kernel.org/r/20231220224504.646757-23-david@redhat.com Signed-off-by: David Hildenbrand Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Muchun Song Cc: Peter Xu Cc: Ryan Roberts Cc: Yin Fengwei Signed-off-by: Andrew Morton

mm/rmap: remove page_add_anon_rmap()

2023-12-29T19:58:52Z

All users are gone, remove it and all traces. Link: https://lkml.kernel.org/r/20231220224504.646757-22-david@redhat.com Signed-off-by: David Hildenbrand Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Muchun Song Cc: Peter Xu Cc: Ryan Roberts Cc: Yin Fengwei Signed-off-by: Andrew Morton

mm/rmap: introduce folio_add_anon_rmap_[pte|ptes|pmd]()

2023-12-29T19:58:50Z

Let's mimic what we did with folio_add_file_rmap_*() so we can similarly replace page_add_anon_rmap() next. Make the compiler always special-case on the granularity by using __always_inline. For the PageAnonExclusive sanity checks, when adding a PMD mapping, we're now also checking each individual subpage covered by that PMD, instead of only the head page. Note that the new functions ignore the RMAP_COMPOUND flag, which we will remove as soon as page_add_anon_rmap() is gone. Link: https://lkml.kernel.org/r/20231220224504.646757-15-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Yin Fengwei Cc: Hugh Dickins Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Muchun Song Cc: Peter Xu Cc: Ryan Roberts Signed-off-by: Andrew Morton