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| author | David Hildenbrand <david@redhat.com> | 2025-02-10 20:37:45 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-03-16 22:05:57 -0700 |
| commit | 599b684a7854e51a51358fe59bbdfea281f0b461 (patch) | |
| tree | 7321c1080d168bbef1537a54de26245fc9b8ff3c /Documentation/mm | |
| parent | bc3fe6805cf09a25a086573a17d40e525208c5d8 (diff) | |
| download | linux-599b684a7854e51a51358fe59bbdfea281f0b461.tar.gz linux-599b684a7854e51a51358fe59bbdfea281f0b461.tar.bz2 linux-599b684a7854e51a51358fe59bbdfea281f0b461.zip | |
mm/rmap: convert make_device_exclusive_range() to make_device_exclusive()
The single "real" user in the tree of make_device_exclusive_range() always
requests making only a single address exclusive. The current
implementation is hard to fix for properly supporting anonymous THP /
large folios and for avoiding messing with rmap walks in weird ways.
So let's always process a single address/page and return folio + page to
minimize page -> folio lookups. This is a preparation for further
changes.
Reject any non-anonymous or hugetlb folios early, directly after GUP.
While at it, extend the documentation of make_device_exclusive() to
clarify some things.
Link: https://lkml.kernel.org/r/20250210193801.781278-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Simona Vetter <simona.vetter@ffwll.ch>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Tested-by: Alistair Popple <apopple@nvidia.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Lyude <lyude@redhat.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yanteng Si <si.yanteng@linux.dev>
Cc: Barry Song <v-songbaohua@oppo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation/mm')
| -rw-r--r-- | Documentation/mm/hmm.rst | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/mm/hmm.rst b/Documentation/mm/hmm.rst index f6d53c37a2ca..7d61b7a8b65b 100644 --- a/Documentation/mm/hmm.rst +++ b/Documentation/mm/hmm.rst @@ -400,7 +400,7 @@ Exclusive access memory Some devices have features such as atomic PTE bits that can be used to implement atomic access to system memory. To support atomic operations to a shared virtual memory page such a device needs access to that page which is exclusive of any -userspace access from the CPU. The ``make_device_exclusive_range()`` function +userspace access from the CPU. The ``make_device_exclusive()`` function can be used to make a memory range inaccessible from userspace. This replaces all mappings for pages in the given range with special swap |