Re: [PATCH] rust: sync: optimize rust symbol generation for CondVar

Alice Ryhl
2025-03-17T10:29:21Z

On Mon, Mar 17, 2025 at 04:13:50PM +0800, Kunwu Chan wrote:
> From: Kunwu Chan <kunwu.chan@hotmail.com>
>
> When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
> with ARCH=arm64, the following symbols are generated:
>
> $nm vmlinux | grep ' _R'.*CondVar | rustfilt
> ... T <kernel::sync::condvar::CondVar>::notify_all
> ... T <kernel::sync::condvar::CondVar>::notify_one
> ... T <kernel::sync::condvar::CondVar>::notify_sync
> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::condvar::CondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::poll::PollCondVar>::new::{closure#0}::{closure#0}::panic_cold_explicit
> ... T <kernel::sync::poll::PollCondVar as core::ops::drop::Drop>::drop
>
> These notify* symbols are trivial wrappers around the C functions
> __wake_up and __wake_up_sync.
> It doesn't make sense to go through a trivial wrapper for these
> functions, so mark them inline.

You don't need to send a new version just for this, but please format
the paragraphs better in the future. For example:

The notify* symbols are trivial wrappers around the C functions
__wake_up and __wake_up_sync. It doesn't make sense to go through a
trivial wrapper for these functions, so mark them inline.

> Link: https://github.com/Rust-for-Linux/linux/issues/1145
> Suggested-by: Alice Ryhl <aliceryhl@google.com>
> Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>

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