Re: [PATCH RFC V6 0/11] Paravirtualized ticketlocks

From: Andi Kleen
Date: Fri Mar 30 2012 - 18:18:52 EST

> So if a guest exits due to an external event it's easy to inspect the
> state of that guest and avoid to schedule away when it was interrupted
> in a spinlock held section. That guest/host shared state needs to be

On a large system under high contention sleeping can perform surprisingly
well. pthread mutexes have a tendency to beat kernel spinlocks there.
So avoiding sleeping locks completely (that is what pv locks are
essentially) is not necessarily that good.

Your proposal is probably only a good idea on low contention
and relatively small systems.

ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at