Re: module as seperate crate

[Wedson Almeida Filho <wedsonaf@google.com>]

Thank you, Miguel!

Finn,

I posted on your PR before, but I think this is a better forum for
this. IIUC, you are implementing the pr_* family of functions and you
need a mutex for that. If this is the case, I think using a mutex is
probably not the ideal solution because it precludes the functions
from being used in contexts where blocking the task is not allowed.

I've just uploaded[1] a WIP commit that contains a SpinLock, which is
probably a better choice. Also, if this is a one-time initialisation
sort of thing, we can probably use a more efficient synchronisation
primitive. If you could describe your needs in more detail we could
probably work something out.

(As for the SpinLock implementation, it also has a condition variable
that uses a generic `Guard`, so if you want to hook your mutex
implementation to this, it will automatically work with the condition
variable too.)

Cheers,
-Wedson

[1] Spin lock commit:
https://github.com/Rust-for-Linux/linux/commit/3a9b3137f6fd179df3dacb72d717f5f4b4d0a266

On Wed, 9 Dec 2020 at 23:20, Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
>
> On Sun, Nov 29, 2020 at 7:30 PM Finn Behrens <me@kloenk.de> wrote:
> >
> > I create a static mut Mutex<&str> (or similar) to contain the pr_fmt
> > string. I cannot init the mutex in a const fn, and so I cannot create an
> > static mut value which already contains a mutex. So I have to call an
> > init_printk functions which creates this mutex. That's all what I'm doing.
> >
> > Will try to get something working the following days, and then send a
> > patch. Mayebe easier to decide then.
>
> This email is just to give Wedson an email thread to reply to. :-)
>
> Cheers,
> Miguel