Re: [PATCH v4 0/7] rust: use Delta instead of raw jiffies for timeouts and delays

On Wed Jul 22, 2026 at 10:49 PM BST, FUJITA Tomonori wrote:
> From: FUJITA Tomonori <[email protected]>
>
> CondVar::wait_interruptible_timeout() and Queue::enqueue_delayed() use
> a raw jiffies count (a plain c_ulong alias with no type
> safety). Callers have to know on their own that the value meant
> jiffies and convert to/from it themselves, which is easy to get wrong
> (e.g. passing a millisecond value where a jiffies value is expected).
>
> Both APIs just take a span of time so, they can use the Delta type
> instead.
>
> This series makes Delta generic over its time unit with Nsec and Jiffy
> types, switches CondVar and Queue to use Delta instead of raw jiffies
> (updating binder's ioctl_freeze(), the only caller of
> wait_interruptible_timeout()), and then removes the now-unused Jiffies
> and Msecs type aliases.

There are more jiffy users being added so we should take this sooner than later:
https://lore.kernel.org/rust-for-linux/[email protected]/#t

Andreas, any plan on taking this via timekeeping-next? I suppose Boqun
could also be taken via rust-sync tree if you give an ack?

(This is obviously a new design so additional reviews are also welcome).

Best,
Gary

>
> ---
> v4:
> - Make Delta generic over its time unit with Nsec and Jiffy types
> v3: https://lore.kernel.org/rust-for-linux/[email protected]/
> - Add new Jiffies type and convert the APIs to take impl Into<Jiffies>
> v2: https://lore.kernel.org/rust-for-linux/[email protected]/
> - Fix potential overflow in from_jiffies()
> - Fix inflating bug in as_jiffies_ceil()
> - Add a patch to convert enqueue_delayed()
> - Add a patch to remove Jiffies/Msecs aliases
> v1: https://lore.kernel.org/rust-for-linux/[email protected]/
>
> ---
> FUJITA Tomonori (7):
>   rust: time: make Delta generic over its time unit
>   rust: time: add jiffies time unit for Delta
>   rust: time: add Delta::as_millis_ceil()
>   rust: time: add Delta::to_jiffies() for timeout conversion
>   rust: workqueue: take a Delta<Jiffy> for the enqueue delay
>   rust: sync: condvar: use Delta<Jiffy> for timeout and result
>   rust: time: remove unused Jiffies/Msecs helpers
>
>  drivers/android/binder/process.rs |   6 +-
>  rust/kernel/sync/condvar.rs       |  29 ++++--
>  rust/kernel/time.rs               | 156 ++++++++++++++++++++++--------
>  rust/kernel/workqueue.rs          |  12 ++-
>  4 files changed, 150 insertions(+), 53 deletions(-)
>
>
> base-commit: 7059bdf4f04a3e14f4fafb3ac35fdca913e3e21a