Messages in this thread | | | Date | Sat, 17 Jan 2015 08:57:44 +0100 | From | Peter Zijlstra <> | Subject | Re: [patch -rt 1/2] KVM: use simple waitqueue for vcpu->wq |
| |
On Fri, Jan 16, 2015 at 11:48:46AM -0500, Steven Rostedt wrote: > I notice everywhere you have a swait_wake_interruptible() but here. Is > there a reason why? > > IIRC, Peter wants to make swait wakeup usage homogenous. That is, you > either sleep in an interruptible state, or you don't. You can't mix and > match it. > > Peter is that what you plan?
Yes, this is required for the single wakeup case to be bounded.
If you have both INTERRUPTIBLE and UNINTERRUPTIBLE waiters on a list, and you were allowed to do INTERRUPTIBLE/UNINTERRUPTIBLE wakeups, the wakeup would have to do O(n) iteration to find a matching waiter.
Seeing that the entire purpose of simple wait queues was to retain RT properties, that's entirely retarded ;-)
| |