Messages in this thread | | | Date | Fri, 28 Aug 2020 10:59:38 +0200 | From | peterz@infradea ... | Subject | Re: [PATCH v1 4/5] seqlock: seqcount_LOCKTYPE_t: Introduce PREEMPT_RT support |
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On Fri, Aug 28, 2020 at 03:07:09AM +0200, Ahmed S. Darwish wrote: > +#define __SEQ_RT IS_ENABLED(CONFIG_PREEMPT_RT) > + > +SEQCOUNT_LOCKTYPE(raw_spinlock, raw_spinlock_t, false, s->lock, raw_spin, raw_spin_lock(s->lock)) > +SEQCOUNT_LOCKTYPE(spinlock, spinlock_t, __SEQ_RT, s->lock, spin, spin_lock(s->lock)) > +SEQCOUNT_LOCKTYPE(rwlock, rwlock_t, __SEQ_RT, s->lock, read, read_lock(s->lock)) > +SEQCOUNT_LOCKTYPE(mutex, struct mutex, true, s->lock, mutex, mutex_lock(s->lock)) > +SEQCOUNT_LOCKTYPE(ww_mutex, struct ww_mutex, true, &s->lock->base, ww_mutex, ww_mutex_lock(s->lock, NULL))
Ooh, reading is hard, but ^^^^ you already have that.
> +/* > + * Automatically disable preemption for seqcount_LOCKTYPE_t writers, if the > + * associated lock does not implicitly disable preemption. > + * > + * Don't do it for PREEMPT_RT. Check __SEQ_LOCK(). > + */ > +#define __seq_enforce_preemption_protection(s) \ > + (!IS_ENABLED(CONFIG_PREEMPT_RT) && __seqcount_lock_preemptible(s))
Then what is this doing ?!? I'm confused now.
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