Messages in this thread | | | Date | Tue, 18 Mar 2014 16:47:24 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH RFC] sched: introduce add_wait_queue_exclusive_head |
| |
On 03/18, Peter Zijlstra wrote: > > I think we can avoid the entire function if we add > WQ_FLAG_LIFO and make prepare_to_wait_event() DTRT.
Agreed, this looks very natural.
prepare_to_wait_event(WQ_FLAG_LIFO) should probably skip all "flags == 0" entries before list_add(). Given that it is supposed that the users won't mix exclusive and !exclusive, perhaps the additional list_for_each() won't hurt?
> Then we only need to teach ___wait() about this; and I suppose we could > make .exclusive=-1 be the LIFO flag.
Or we can change ___wait_event()
- if (exclusive) \ - __wait.flags = WQ_FLAG_EXCLUSIVE; \ - else \ - __wait.flags = 0; \ + __wait.flags = exclusive; \
and obviously change the callers. Perhaps this argument should be renamed then.
But I am fine either way, just I like the idea to extend the current interface.
Oleg.
| |