Re: [PATCH] rust: sync: add wait_interruptible_freezable

[Alice Ryhl]

On Mon, Feb 3, 2025 at 12:54 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Thu, Jan 30, 2025 at 11:30:44AM +0000, Alice Ryhl wrote:
> > Binder allows you to freeze a process where some of its threads are
> > blocked on the Binder driver. To make this work, we need to pass
> > TASK_FREEZABLE when going to sleep in the appropriate places. Thus, add
> > a new method wait_interruptible_freezable for the condition variable so
> > that sleeps where this is supported can be marked as such.
>
> The constraint on freezable is that you must not hold locks. There is a
> lockdep check for this in the code, but it would probably make sense to
> teach Rust about this constraint as well, hmm?

Unfortunately, I don't think there's any way to enforce this at
compile time, but I'm definitely happy to add this in the
documentation.

Thanks!
Alice