On Mon, May 10, 2021 at 9:30 AM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > On Mon, May 10, 2021 at 09:16:58AM +0200, Daniel Vetter wrote: > > > End result: not pulling it, unless somebody can explain to me in small > > > words why I'm wrong and have the mental capacity of a damaged rodent. > > > > No rodents I think, just more backstory of how this all fits. tldr; > > pin_user_pages is the only safe use of this vb2 userptr thing. > > Yes, which is why I advocate for just ripping the follow_pfn path > out entirely. It could have been used for crazy ad dangerous peer to > peer transfers outside of any infrastructure making it safe, or for > pre-CMA kernel memory carveouts for lage contiguous memory allocations > (which are pretty broken by design as well). So IMHO the only sensible > thing is to remove this cruft entirely, and if it breaks a currently > working setup (which I think is unlikely) we'll have to make sure it > can work the proper way. Since I'm not getting any cozy consenus vibes here on any option I think I'll just drop this. Stephen, can you pls drop git://anongit.freedesktop.org/drm/drm topic/iomem-mmap-vs-gup from linux-next? It's not going anywhere. I'll also go ahead and delete the branch, to make sure you catch this update :-) Thanks, Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
