On Thu Nov 10, 2022 at 10:36 AM AEST, Jordan Niethe wrote:
> On Thu, 2022-07-28 at 16:31 +1000, Nicholas Piggin wrote:
>
> [resend as utf-8, not utf-7]
> >
> > +/*
> > + * Bitfields in the atomic value:
> > + *
> > + * 0: locked bit
> > + * 16-31: tail cpu (+1)
> > + */
> > +#define_Q_SE
On Thu, 2022-07-28 at 16:31 +1000, Nicholas Piggin wrote:
[resend as utf-8, not utf-7]
>
> +/*
> + * Bitfields in the atomic value:
> + *
> + * 0: locked bit
> + * 16-31: tail cpu (+1)
> + */
> +#define _Q_SET_MASK(type) (((1U << _Q_ ## type ## _BITS) - 1)\
> +
On Thu, 2022-07-28 at 16:31 +1000, Nicholas Piggin wrote:
>
> +/*
> + * Bitfields in the atomic value:
> + *
> + * 0: locked bit
> + * 16-31: tail cpu (+1)
> + */
> +#define _Q_SET_MASK(type) (((1U << _Q_ ## type ## _BITS) - 1)\
> + << _Q_ ## typ
This forms the basis of the qspinlock slow path.
Like generic qspinlocks and unlike the vanilla MCS algorithm, the lock
owner does not participate in the queue, only waiters. The first waiter
spins on the lock word, then when the lock is released it takes
ownership and unqueues the next waiter. Th
