[PATCH v6 2/6] rust: bitmap: add BitmapVec::new_inline()

Alice Ryhl
2025-11-25T13:59:58Z

This constructor is useful when you just want to create a BitmapVec
without allocating but don't care how large it is.

Acked-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Reviewed-by: Burak Emir <bqe@google.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
rust/kernel/bitmap.rs | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/rust/kernel/bitmap.rs b/rust/kernel/bitmap.rs
index 0705646c6251a49f213a45f1f013cb9eb2ed81de..83d7dea99137ded7cba47ec5a3bf10bb7e13f2d2 100644
--- a/rust/kernel/bitmap.rs
+++ b/rust/kernel/bitmap.rs
@@ -230,6 +230,16 @@ impl BitmapVec {
/// The maximum length that uses the inline representation.
pub const MAX_INLINE_LEN: usize = usize::BITS as usize;

+ /// Construct a longest possible inline [`BitmapVec`].
+ #[inline]
+ pub fn new_inline() -> Self {
+ // INVARIANT: `nbits <= MAX_INLINE_LEN`, so an inline bitmap is the right repr.
+ BitmapVec {
+ repr: BitmapRepr { bitmap: 0 },
+ nbits: BitmapVec::MAX_INLINE_LEN,
+ }
+ }
+
/// Constructs a new [`BitmapVec`].
///
/// Fails with [`AllocError`] when the [`BitmapVec`] could not be allocated. This

--
2.52.0.460.gd25c4c69ec-goog