On Tue, May 22, 2018 at 02:52:54PM -0400, Mike Snitzer wrote: > On Tue, May 22 2018 at 2:34am -0400, > Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > Please CC the author and maintainers of the swait code. > > > > My impression is that this is the wrong thing to do. The swait code > > is supposed to be simple and self contained, and if you want to do > > anything else use normal waitqueues. > > You said the same thing last time around. I've since cc'd Peter and > Thomas and haven't heard back, see: > https://www.redhat.com/archives/dm-devel/2018-May/msg00048.html Yeah, sorry, got lost :/ > The entire point of exporting these symbols is to allow use of the > "simple waitqueue" code to optimize -- without resorting to using normal > waitqueues. So I don't immediately object to exporting them; however I do share some of hch's concerns. The reason swait exists is to be deterministic (for RT) -- something that regular wait code cannot be. And by (ab)using / exporting the wait internal lock you risk loosing that. So I don't think the proposed usage is bad, it is possible to create badness. So if we're going to export them; someone needs to keep an eye on things and ensure the lock isn't abused. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
