rust/helpers.c | 7 + rust/kernel/alloc/box_ext.rs | 24 +- rust/kernel/lib.rs | 1 + rust/kernel/rbtree.rs | 1288 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 1319 insertions(+), 1 deletion(-)
This patchset contains the red-black tree abstractions needed by the Rust
implementation of the Binder driver.
Binder driver benefits from O(log n) search/insertion/deletion of
key/value mappings in various places, including `process.rs` and
`range_alloc.rs`. In `range_alloc.rs`, the ability to store and
search by a generic key type is also useful.
Please see the Rust Binder RFC for usage examples [1]. Note that
the `container_of` macro is currently used only by `rbtree` itself.
Users of "rust: rbtree: add red-black tree implementation backed by the C version"
[PATCH RFC 03/20] rust_binder: add threading support
[PATCH RFC 05/20] rust_binder: add nodes and context managers
[PATCH RFC 06/20] rust_binder: add oneway transactions
Users of "rust: rbtree: add iterator"
[PATCH RFC 17/20] rust_binder: add oneway spam detection
Users of "rust: rbtree: add mutable iterator"
[PATCH RFC 06/20] rust_binder: add oneway transactions
Users of "rust: rbtree: add `RBTreeCursor`"
[PATCH RFC 06/20] rust_binder: add oneway transactions
Users of "rust: rbtree: add RBTree::entry"
Not used in the original RFC, but introduced after further
code review. See: https://r.android.com/2849906
The Rust Binder RFC addresses the upstream deprecation of red-black
tree. Quoted here for convenience:
"This RFC uses the kernel's red-black tree for key/value mappings, but we
are aware that the red-black tree is deprecated. We did this to make the
performance comparison more fair, since C binder also uses rbtree for
this. We intend to replace these with XArrays instead. That said, we
don't think that XArray is a good fit for the range allocator, and we
propose to continue using the red-black tree for the range allocator."
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-0-08ba9197f637@google.com/ [1]
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
---
Changes in v8:
- Fix small style nit (use ? operator)
- Fix doc comment pointing at a private item
- Link to v7: https://lore.kernel.org/r/20240726-b4-rbtree-v7-0-aee88caaf97c@google.com
Changes in v7:
- make `RawVacantEntry.rbtree` a raw pointer like
`RawVacantEntry.child_field_of_parent`, since the latter can
technically point at a field of the former. We prefer that the
implementation be explicit about the safety guarantees of both because
of the relationship between them.
- Link to v6: https://lore.kernel.org/r/20240711-b4-rbtree-v6-0-14bef1a8cdba@google.com
Changes in v6:
- Minimize usage of `*mut bindings::rb_node`, replacing with
`NonNull<bindings::rb_node>`. Specifically, changing
`RBTreeCursor.current` to be `NonNull<bindings::rb_node>` and updating
the corresponding functions.
- Update `RBTreeCursor:to_key_value` helpers to have their own lifetime
(they are not instance methods, using a different lifetime than that
of the `impl` block they are in makes things more clear.
- Fix misplaced semicolon in `cursor_lower_bound`.
- Link to v5: https://lore.kernel.org/r/20240606-b4-rbtree-v5-0-96fe1a0e97c0@google.com
Changes in v5:
- Used `Box::write` in `RBTreeNodeReservation::into_node`, removing
unnecessary `unsafe` blocks.
- Updated `RBTreeCursor::remove_current` to return the removed node.
- Link to v4: https://lore.kernel.org/r/20240603-b4-rbtree-v4-0-308e43d6abfc@google.com
Changes in v4:
- rebased onto the tip of rust-for-linux/rust-next (97ab3e8eec0ce79d9e265e6c9e4c480492180409)
- addressed comments from draft PR on GitHub: https://github.com/Rust-for-Linux/linux/pull/1081
- Link to v3: https://lore.kernel.org/r/20240418-b4-rbtree-v3-0-323e134390ce@google.com
Changes in v3:
- Address various feedback re: SAFETY and INVARIANT comments from v2.
- Update variable naming and add detailed comments for the `RBTree::insert` (later moved to
`RBTree::raw_entry`) implementation.
- Link to v2: https://lore.kernel.org/r/20240219-b4-rbtree-v2-0-0b113aab330d@google.com
Changes in v2:
- Update documentation link to the C header file
- Use `core::convert::Infallible` in try_reserve_node
- Link to v1: https://lore.kernel.org/r/20240205-b4-rbtree-v1-0-995e3eee38c0@google.com
---
Alice Ryhl (1):
rust: rbtree: add `RBTree::entry`
Benno Lossin (1):
rust: kernel: add `drop_contents` to `BoxExt`
Matt Gilbride (1):
rust: rbtree: add `RBTreeCursor`
Wedson Almeida Filho (3):
rust: rbtree: add red-black tree implementation backed by the C version
rust: rbtree: add iterator
rust: rbtree: add mutable iterator
rust/helpers.c | 7 +
rust/kernel/alloc/box_ext.rs | 24 +-
rust/kernel/lib.rs | 1 +
rust/kernel/rbtree.rs | 1288 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 1319 insertions(+), 1 deletion(-)
---
base-commit: 97ab3e8eec0ce79d9e265e6c9e4c480492180409
change-id: 20231205-b4-rbtree-abb1a016f0a0
Best regards,
--
Matt Gilbride <mattgilbride@google.com>
On Sat, Jul 27, 2024 at 08:30:45PM +0000, Matt Gilbride wrote: > This patchset contains the red-black tree abstractions needed by the Rust > implementation of the Binder driver. > > Binder driver benefits from O(log n) search/insertion/deletion of > key/value mappings in various places, including `process.rs` and > `range_alloc.rs`. In `range_alloc.rs`, the ability to store and > search by a generic key type is also useful. > > Please see the Rust Binder RFC for usage examples [1]. Note that > the `container_of` macro is currently used only by `rbtree` itself. > > Users of "rust: rbtree: add red-black tree implementation backed by the C version" > [PATCH RFC 03/20] rust_binder: add threading support > [PATCH RFC 05/20] rust_binder: add nodes and context managers > [PATCH RFC 06/20] rust_binder: add oneway transactions > > Users of "rust: rbtree: add iterator" > [PATCH RFC 17/20] rust_binder: add oneway spam detection > > Users of "rust: rbtree: add mutable iterator" > [PATCH RFC 06/20] rust_binder: add oneway transactions > > Users of "rust: rbtree: add `RBTreeCursor`" > [PATCH RFC 06/20] rust_binder: add oneway transactions > > Users of "rust: rbtree: add RBTree::entry" > Not used in the original RFC, but introduced after further > code review. See: https://r.android.com/2849906 > > The Rust Binder RFC addresses the upstream deprecation of red-black > tree. Quoted here for convenience: > > "This RFC uses the kernel's red-black tree for key/value mappings, but we > are aware that the red-black tree is deprecated. We did this to make the > performance comparison more fair, since C binder also uses rbtree for > this. We intend to replace these with XArrays instead. That said, we > don't think that XArray is a good fit for the range allocator, and we > propose to continue using the red-black tree for the range allocator." > > Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-0-08ba9197f637@google.com/ [1] > Signed-off-by: Matt Gilbride <mattgilbride@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Again, I drop patch #1 and put it in rust-dev with conflicts fixed. Regards, Boqun > --- > Changes in v8: > - Fix small style nit (use ? operator) > - Fix doc comment pointing at a private item > - Link to v7: https://lore.kernel.org/r/20240726-b4-rbtree-v7-0-aee88caaf97c@google.com > > Changes in v7: > - make `RawVacantEntry.rbtree` a raw pointer like > `RawVacantEntry.child_field_of_parent`, since the latter can > technically point at a field of the former. We prefer that the > implementation be explicit about the safety guarantees of both because > of the relationship between them. > - Link to v6: https://lore.kernel.org/r/20240711-b4-rbtree-v6-0-14bef1a8cdba@google.com > > Changes in v6: > - Minimize usage of `*mut bindings::rb_node`, replacing with > `NonNull<bindings::rb_node>`. Specifically, changing > `RBTreeCursor.current` to be `NonNull<bindings::rb_node>` and updating > the corresponding functions. > - Update `RBTreeCursor:to_key_value` helpers to have their own lifetime > (they are not instance methods, using a different lifetime than that > of the `impl` block they are in makes things more clear. > - Fix misplaced semicolon in `cursor_lower_bound`. > - Link to v5: https://lore.kernel.org/r/20240606-b4-rbtree-v5-0-96fe1a0e97c0@google.com > > Changes in v5: > - Used `Box::write` in `RBTreeNodeReservation::into_node`, removing > unnecessary `unsafe` blocks. > - Updated `RBTreeCursor::remove_current` to return the removed node. > - Link to v4: https://lore.kernel.org/r/20240603-b4-rbtree-v4-0-308e43d6abfc@google.com > > Changes in v4: > - rebased onto the tip of rust-for-linux/rust-next (97ab3e8eec0ce79d9e265e6c9e4c480492180409) > - addressed comments from draft PR on GitHub: https://github.com/Rust-for-Linux/linux/pull/1081 > - Link to v3: https://lore.kernel.org/r/20240418-b4-rbtree-v3-0-323e134390ce@google.com > > Changes in v3: > - Address various feedback re: SAFETY and INVARIANT comments from v2. > - Update variable naming and add detailed comments for the `RBTree::insert` (later moved to > `RBTree::raw_entry`) implementation. > - Link to v2: https://lore.kernel.org/r/20240219-b4-rbtree-v2-0-0b113aab330d@google.com > > Changes in v2: > - Update documentation link to the C header file > - Use `core::convert::Infallible` in try_reserve_node > - Link to v1: https://lore.kernel.org/r/20240205-b4-rbtree-v1-0-995e3eee38c0@google.com > > --- > Alice Ryhl (1): > rust: rbtree: add `RBTree::entry` > > Benno Lossin (1): > rust: kernel: add `drop_contents` to `BoxExt` > > Matt Gilbride (1): > rust: rbtree: add `RBTreeCursor` > > Wedson Almeida Filho (3): > rust: rbtree: add red-black tree implementation backed by the C version > rust: rbtree: add iterator > rust: rbtree: add mutable iterator > > rust/helpers.c | 7 + > rust/kernel/alloc/box_ext.rs | 24 +- > rust/kernel/lib.rs | 1 + > rust/kernel/rbtree.rs | 1288 ++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 1319 insertions(+), 1 deletion(-) > --- > base-commit: 97ab3e8eec0ce79d9e265e6c9e4c480492180409 > change-id: 20231205-b4-rbtree-abb1a016f0a0 > > Best regards, > -- > Matt Gilbride <mattgilbride@google.com> >
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