On Wed, Jun 17, 2020 at 09:57:54AM +0200, Daniel Vetter wrote: > > At the very least I think there should be some big warning that > > dma_fence in notifiers should be avoided. > > Yeah I'm working on documentation, and also the notifiers here > hopefully make it clear it's massive pain. I think we could even make > a hard rule that dma_fence in mmu notifier outside of drivers/gpu is a > bug/misfeature. Yep! > Might be a good idea to add a MAINTAINERS entry with a K: regex > pattern, so that you can catch such modifiers. We do already have such > a pattern for dma-fence, to catch abuse. So if you want I could type > up a documentation patch for this, get your and others acks and the > dri-devel folks would enforce that the dma_fence_wait madness doesn't > leak beyond drivers/gpu It seems like the best thing > Oded has agreed to remove the dma-fence usage, since they really don't > need it (and all the baggage that comes with it), plain old completion > is enough for their use. This use is also why I added the regex to > MAINTAINERS, so that in the future we can catch people who try to use > dma_fence because it looks cute and useful, and are completely > oblivious to all the pain and headaches involved. This is good! Thanks, Jason
