On Thu, Nov 24, 2016 at 12:26:57PM +0100, Nicolai Hähnle wrote: > I do believe we can win a bit by keeping the wait list sorted, if we also > make sure that waiters don't add themselves in the first place if they see > that a deadlock situation cannot be avoided. > > I will probably want to extend struct mutex_waiter with ww_mutex-specific > fields to facilitate this (i.e. ctx pointer, perhaps stamp as well to reduce > pointer-chasing). That should be fine since it lives on the stack. Right, shouldn't be a problem I think. The only 'problem' I can see with using that is that its possible to mix ww and !ww waiters through ww_mutex_lock(.ctx = NULL). This makes the list order somewhat tricky. Ideally we'd remove that feature, although I see its actually used quite a bit :/ > In the meantime, I'd appreciate it if patch #1 could be accepted as-is for > stable updates to <= 4.8. It fixes a real (if rare) bug, and the stampede > inefficiency isn't a problem in practice at least for GPU applications. Sorry can't do. We don't do stable patches that don't have anything upstream. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
