On Wed, Feb 17, 2016 at 08:53:18PM +1100, Dave Chinner wrote:
> > +/**
> > + * for_all_percpu_list_entries - iterate over all the per-cpu list with
> > locking
> > + * @pos: the type * to use as a loop cursor for the current .
> > + * @next: an internal type * variable pointing to the next entry
> > + * @pchead: an internal struct list * of percpu list head
> > + * @pclock: an internal variable for the current per-cpu spinlock
> > + * @head: the head of the per-cpu list
> > + * @member: the name of the per-cpu list within the struct
> > + */
> > +#define for_all_percpu_list_entries(pos, next, pchead, pclock, head,
> > member)\
> > + { \
> > + int cpu; \
> > + for_each_possible_cpu (cpu) { \
> > + typeof(*pos) *next; \
> > + spinlock_t *pclock = per_cpu_ptr(&(head)->lock, cpu); \
> > + struct list_head *pchead = &per_cpu_ptr(head, cpu)->list;\
> > + spin_lock(pclock); \
> > + list_for_each_entry_safe(pos, next, pchead, member.list)
> > +
> > +#define end_all_percpu_list_entries(pclock) spin_unlock(pclock); } }
>
> This is a bit of a landmine
Yeah, that is pretty terrible. Maybe a visitor interface is advisable?
visit_percpu_list_entries(struct percpu_list *head, void (*visitor)(struct
list_head *pos, void *data), void *data)
{
int cpu;
for_each_possible_cpu(cpu) {
spinlock_t *lock = per_cpu_ptr(&head->lock, cpu);
struct list_head *head = per_cpu_ptr(&head->list, cpu);
struct list_head *pos, *tmp;
spin_lock(lock);
for (pos = head->next, tmp = pos->next; pos != head; pos = tmp)
visitor(pos, data);
spin_unlock(lock);
}
}
