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a=openpgp; fpr=49F6C1FAA74960F43A5B86A1EE7A392FDE96209F X-Developer-Signature: v=1; a=openpgp-sha256; l=1143; i=aliceryhl@google.com; h=from:subject:message-id; bh=0XwGJ7KDobiszudqfhO29Z8TfiNZOYymA4jTezIL42U=; b=owEBbQKS/ZANAwAKAQRYvu5YxjlGAcsmYgBo94uX6Ot6RnX1kq5rBoe1JUBm01b6sLrSgsNH1 eKsmbT+mcCJAjMEAAEKAB0WIQSDkqKUTWQHCvFIvbIEWL7uWMY5RgUCaPeLlwAKCRAEWL7uWMY5 RjfND/9CZXLAKgrrXYLqvMdfR8KG2+6kgkJSVz/EOx4eNESv/IO6/C27XHCmPinb9KlxDcdav18 aYSFcqBOpC46LSJbsy90DqSqte+m5GXPToraWHYXv82fGe4erjE3HsmuczbkSqj0NHbG4UZpaHh 69juPv50aIuU2SP2hJsIWsbVvv3NZOEb9/RCVRWs94HrTrX0CeqGBEKPQPpzC7fAE+EC8cCvn06 R6WaDVrVLumwC4szYX73+tymfucNpeYh6UkYKlYB6uPlnVFBExPuCnqGL+nZJ6pZ8/9AjUGwrRi 2LyQK9ykynZk943Gi3dIKDt2PgFk7HlXmu7Qd3ylp69IzCWe0jLeZRa+2yj+B2m2LR0lchGfBp6 JYVBwsoYEPsUZIGuiffHpPM9aPRghyptFWjLTV5OKlQdkEwqeELRm8WttpZTBavnbQajHZxdG7r ZGB1qWVLxoFGQ1HS6QlaffQcKJ+vABQUse+JfPnYrHHpkdhRw5qn3k55gn/atSodOjsUw+z1M/C 16DGa6f0WEbf5p3T0goHvB1JeDJUIuVx/QMA9ph2GgZxEbkHWHreI+q0/5mZq642VU0b+VKlcu1 lVyKhDshbxDEmhvsCdUcUcM1T30endAzOjHOcz+c+4GRbZmxo+pVlat/t6bzT50UlPa/PxqfuxD +OM1cn2CppoUvww== X-Mailer: b4 0.14.2 Message-ID: <20251021-binder-bitmap-v2-2-e652d172c62b@google.com> Subject: [PATCH v2 2/5] rust: bitmap: add BitmapVec::new_small() From: Alice Ryhl To: Greg Kroah-Hartman , Yury Norov Cc: "=?utf-8?q?Arve_Hj=C3=B8nnev=C3=A5g?=" , Todd Kjos , Martijn Coenen , Joel Fernandes , Christian Brauner , Carlos Llamas , Suren Baghdasaryan , Burak Emir , Miguel Ojeda , Boqun Feng , Gary Guo , "=?utf-8?q?Bj=C3=B6rn_Roy_Baron?=" , Benno Lossin , Andreas Hindborg , Trevor Gross , Danilo Krummrich , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Alice Ryhl Content-Type: text/plain; charset="utf-8" This constructor is useful when you just want to create a BitmapVec without allocating but don't care how large it is. Signed-off-by: Alice Ryhl --- rust/kernel/bitmap.rs | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/rust/kernel/bitmap.rs b/rust/kernel/bitmap.rs index 15fa23b45054b9272415fcc000e3e3b52c74d7c1..4ffe9eb0f208a3d62016e00297f5a0800aa33336 100644 --- a/rust/kernel/bitmap.rs +++ b/rust/kernel/bitmap.rs @@ -232,6 +232,16 @@ impl BitmapVec { /// The maximum length that avoids allocating. pub const NO_ALLOC_MAX_LEN: usize = BITS_PER_LONG; + /// Constructs a new [`BitmapVec`] without allocating. + #[inline] + pub fn new_small() -> Self { + // INVARIANT: `nbits <= NO_ALLOC_MAX_LEN`, so an inline bitmap is the right repr. + BitmapVec { + repr: BitmapRepr { bitmap: 0 }, + nbits: BitmapVec::NO_ALLOC_MAX_LEN, + } + } + /// Constructs a new [`BitmapVec`]. /// /// Fails with [`AllocError`] when the [`BitmapVec`] could not be allocated. This -- 2.51.0.869.ge66316f041-goog