On Thu, Jan 06, 2022 at 10:06:42PM -0500, Daniel Jordan wrote: > > At least it seems like it is not an insurmountable problem if it makes > > an appreciable difference.. > > Ok, I can think more about this. Unfortunately iommufd is not quite ready yet, otherwise I might suggest just focus on that not type 1 optimizations. Depends on your timeframe I suppose. > > After seeing Daniels's patches I've been wondering if the pin step in > > iommufd's draft could be parallized on a per-map basis without too > > much trouble. It might give Daniel a way to do a quick approach > > comparison.. > > Sorry, comparison between what? I can take a look at iommufd tomorrow > though and see if your comment makes more sense. I think it might be easier to change the iommufd locking than the type1 locking to allow kernel-side parallel map ioctls. It is already almost properly locked for this right now, just the iopt lock covers a little bit too much. It could give some idea what kind of performance user managed concurrency gives vs kernel auto threading. Jason
