On Mon, Jun 22, 2026 at 07:32:49PM +0200, Philipp Stanner wrote: > synchronize_rcu() is a frequently used C function which is always safe > to be called. > > Add a safe abstraction for synchronize_rcu(). > > Signed-off-by: Philipp Stanner <[email protected]> > --- > rust/kernel/sync/rcu.rs | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/rust/kernel/sync/rcu.rs b/rust/kernel/sync/rcu.rs > index a32bef6e490b..0d438ef31766 100644 > --- a/rust/kernel/sync/rcu.rs > +++ b/rust/kernel/sync/rcu.rs > @@ -50,3 +50,12 @@ fn drop(&mut self) { > pub fn read_lock() -> Guard { > Guard::new() > } > + > +/// Wait for one RCU grace period. > +/// > +/// You typically do this to wait for everyone holding a [`Guard`]. > +#[inline] > +pub fn synchronize_rcu() { > + // SAFETY: `synchronize_rcu()` is always safe to be called. It just > waits for a grace period.
Commething randomly here (I know as much rust as the next not-knowing-rust-guy, sadly), but synchronize_rcu() is not always safe to be called. You cannot call it if you have the rcu read lock, or cannot sleep for any reason. I don't know if you can encode these in the rust type system though. -- Pedro
