On Tue, 5 Feb 2008, Nick Piggin wrote: > Ok. But the approach is just not so good. If you _really_ need something > like that and it is a win over the regular non-atomic unlock, then you > just have to implement it as a generic locking / atomic operation and > allow all architectures to implement the optimal (and correct) memory > barriers.
Assuming this really gives a benefit on several benchmarks then we need to think about how to do this some more. Its a rather strange form of locking. Basically you lock the page with a single atomic operation that sets PageLocked and retrieves the page flags. Then we shovel the page state around a couple of functions in a register and finally store the page state back which at the same time unlocks the page. So two memory references with one of them being atomic with none in between. We have nothing that can do something like that right now. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
