On Tue, Jan 07, 2014 at 09:29:45AM +0100, Marin Ramesa wrote: > On 01/06/2014 03:00:35 PM, Richard Braun wrote: > >We also need to make sure nothing bad happens to an (object, offset) > >pair when, say, copy-on-write is performed by the VM system... > > I'll add a check_consistency() routine to futex_wake() which repeats the > vm_map_lookup(). I'll use a sum of object address and offset for the > event.
I'm not sure you get the point. The problem is that copy-on-write will create shadow objects, possibly making your new lookup wrong. But normally, such mappings are private, where a task-local address will do the job whatever the mapping type, as long as it's valid. > So, if the event is not the same, I'll just return from futex_wake(). > >All this looks quite tricky to me, and certainly not a "small hack > >entry" :-/. > > I won't give up. I've spent too much time on this already. I guess > I'll just > have to finish it. Hum no, this is clearly not "too much time" yet. But I understand. Just know that we may not be able to find the time to validate and debug your code. I'm looking at it as a reviewer only, I will miss tricky details too, and I won't test it since I have other things on my to do list. Same goes for practically everyone else involved in the project. Expect to be on your own for much of the development. -- Richard Braun
