* [PATCH v3] rust: Mark all from() for Error functions inline
@ 2026-03-26 2:04 ` alistair23
2026-03-27 10:46 ` Andreas Hindborg
2026-03-27 11:56 ` Miguel Ojeda
0 siblings, 2 replies; 3+ messages in thread
From: alistair23 @ 2026-03-26 2:04 UTC (permalink / raw)
To: dakr, ljs, vbabka, Liam.Howlett, urezki, ojeda, boqun, gary,
bjorn3_gh, lossin, a.hindborg, aliceryhl, tmgross, tamird, work,
acourbot, rust-for-linux, linux-kernel
Cc: alistair23, Alistair Francis
From: Alistair Francis <alistair.francis@wdc.com>
Mark all of the existing
impl From<...> for Error {
fn from(err: ...) -> Self {
...
}
}
functions as `#[inline]`
There was a recent request [1] to inline the simple from() Error
functions to avoid the function call overhead.
This patch inlines all of the functions (except for the pin-initi and
syn) and converts one existing `inline(always)` to `inline` to match
the styles.
Link: https://lore.kernel.org/all/CAH5fLggOnVguVErjySphX__vs3iYAo4O+J6hrXW546JrWSq5ZA@mail.gmail.com/ [1]
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
---
v3:
- Convert Link to use lore.kernel.org
- Drop change to syn
rust/kernel/alloc/kvec/errors.rs | 3 +++
rust/kernel/error.rs | 6 ++++++
rust/kernel/ptr/projection.rs | 2 +-
rust/kernel/xarray.rs | 1 +
4 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/rust/kernel/alloc/kvec/errors.rs b/rust/kernel/alloc/kvec/errors.rs
index e7de5049ee47..985c5f2c3962 100644
--- a/rust/kernel/alloc/kvec/errors.rs
+++ b/rust/kernel/alloc/kvec/errors.rs
@@ -15,6 +15,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
}
impl<T> From<PushError<T>> for Error {
+ #[inline]
fn from(_: PushError<T>) -> Error {
// Returning ENOMEM isn't appropriate because the system is not out of memory. The vector
// is just full and we are refusing to resize it.
@@ -32,6 +33,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
}
impl From<RemoveError> for Error {
+ #[inline]
fn from(_: RemoveError) -> Error {
EINVAL
}
@@ -55,6 +57,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
}
impl<T> From<InsertError<T>> for Error {
+ #[inline]
fn from(_: InsertError<T>) -> Error {
EINVAL
}
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 258b12afdcba..935787c2a91c 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -216,36 +216,42 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
}
impl From<AllocError> for Error {
+ #[inline]
fn from(_: AllocError) -> Error {
code::ENOMEM
}
}
impl From<TryFromIntError> for Error {
+ #[inline]
fn from(_: TryFromIntError) -> Error {
code::EINVAL
}
}
impl From<Utf8Error> for Error {
+ #[inline]
fn from(_: Utf8Error) -> Error {
code::EINVAL
}
}
impl From<LayoutError> for Error {
+ #[inline]
fn from(_: LayoutError) -> Error {
code::ENOMEM
}
}
impl From<fmt::Error> for Error {
+ #[inline]
fn from(_: fmt::Error) -> Error {
code::EINVAL
}
}
impl From<core::convert::Infallible> for Error {
+ #[inline]
fn from(e: core::convert::Infallible) -> Error {
match e {}
}
diff --git a/rust/kernel/ptr/projection.rs b/rust/kernel/ptr/projection.rs
index 140ea8e21617..7e37390da6c6 100644
--- a/rust/kernel/ptr/projection.rs
+++ b/rust/kernel/ptr/projection.rs
@@ -13,7 +13,7 @@
pub struct OutOfBound;
impl From<OutOfBound> for Error {
- #[inline(always)]
+ #[inline]
fn from(_: OutOfBound) -> Self {
ERANGE
}
diff --git a/rust/kernel/xarray.rs b/rust/kernel/xarray.rs
index a49d6db28845..46e5f43223fe 100644
--- a/rust/kernel/xarray.rs
+++ b/rust/kernel/xarray.rs
@@ -172,6 +172,7 @@ pub struct StoreError<T> {
}
impl<T> From<StoreError<T>> for Error {
+ #[inline]
fn from(value: StoreError<T>) -> Self {
value.error
}
--
2.53.0
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