The assert in the doctest used `>= 10`, which only checks that the
capacity can hold `additional` elements, ignoring the existing length
of `v`. The correct check should ensure there is room for `additional`
*extra* elements on top of what is already in the vector.

Fix the assert to use `>= v.len() + 10` so the example accurately
reflects the actual semantics of the function.

Reported-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Closes: https://lore.kernel.org/rust-for-linux/CANiq72nkXWhjK9iFRrhGtkMZGsvNE_zVsu4JnxaFRfxWL7RRdg@mail.gmail.com/
Fixes: 2aac4cd7dae3d ("rust: alloc: implement kernel `Vec` type")
Signed-off-by: Hsiu Che Yu <yu.whisper.personal@gmail.com>
---
 rust/kernel/alloc/kvec.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rust/kernel/alloc/kvec.rs b/rust/kernel/alloc/kvec.rs
index ac8d6f763ae8..d05f3835cf53 100644
--- a/rust/kernel/alloc/kvec.rs
+++ b/rust/kernel/alloc/kvec.rs
@@ -611,7 +611,7 @@ pub fn clear(&mut self) {
     ///
     /// v.reserve(10, GFP_KERNEL)?;
     /// let cap = v.capacity();
-    /// assert!(cap >= 10);
+    /// assert!(cap >= v.len() + 10);
     ///
     /// v.reserve(10, GFP_KERNEL)?;
     /// let new_cap = v.capacity();

---
base-commit: b4e07588e743c989499ca24d49e752c074924a9a
change-id: 20260427-doctest-kvec-reserve-6a84e832b05e

Best regards,
--  
Hsiu Che Yu <yu.whisper.personal@gmail.com>

On Mon, 27 Apr 2026 22:15:49 +0800, Hsiu Che Yu wrote:
> [PATCH] rust: alloc: fix assert in `Vec::reserve` doc test

Applied, thanks!

  Branch: alloc-next
  Tree:   git@github.com:Rust-for-Linux/linux.git

[1/1] rust: alloc: fix assert in `Vec::reserve` doc test
      commit: 75619f2df7a5

The patch will appear in the next linux-next integration (typically within 24
hours on weekdays).

The patch is queued up for the upcoming merge window for the next major kernel
release.

On Mon, Apr 27, 2026 at 10:15:49PM +0800, Hsiu Che Yu wrote:
> The assert in the doctest used `>= 10`, which only checks that the
> capacity can hold `additional` elements, ignoring the existing length
> of `v`. The correct check should ensure there is room for `additional`
> *extra* elements on top of what is already in the vector.
> 
> Fix the assert to use `>= v.len() + 10` so the example accurately
> reflects the actual semantics of the function.
> 
> Reported-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
> Closes: https://lore.kernel.org/rust-for-linux/CANiq72nkXWhjK9iFRrhGtkMZGsvNE_zVsu4JnxaFRfxWL7RRdg@mail.gmail.com/
> Fixes: 2aac4cd7dae3d ("rust: alloc: implement kernel `Vec` type")
> Signed-off-by: Hsiu Che Yu <yu.whisper.personal@gmail.com>

Reviewed-by: Alice Ryhl <aliceryhl@google.com>

On Mon Apr 27, 2026 at 11:15 PM JST, Hsiu Che Yu wrote:
> The assert in the doctest used `>= 10`, which only checks that the
> capacity can hold `additional` elements, ignoring the existing length
> of `v`. The correct check should ensure there is room for `additional`
> *extra* elements on top of what is already in the vector.
>
> Fix the assert to use `>= v.len() + 10` so the example accurately
> reflects the actual semantics of the function.
>
> Reported-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
> Closes: https://lore.kernel.org/rust-for-linux/CANiq72nkXWhjK9iFRrhGtkMZGsvNE_zVsu4JnxaFRfxWL7RRdg@mail.gmail.com/
> Fixes: 2aac4cd7dae3d ("rust: alloc: implement kernel `Vec` type")
> Signed-off-by: Hsiu Che Yu <yu.whisper.personal@gmail.com>

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>