On Thu 2019-07-18 22:57:48, Christoph Hellwig wrote: > On Thu, Jul 18, 2019 at 06:32:53PM -0700, john.hubbard@gmail.com wrote: > > + HMM_MIRROR provides a way to mirror ranges of the CPU page tables > > + of a process into a device page table. Here, mirror means "keep > > + synchronized". Prerequisites: the device must provide the ability > > + to write-protect its page tables (at PAGE_SIZE granularity), and > > + must be able to recover from the resulting potential page faults. > > + > > + Select HMM_MIRROR if you have hardware that meets the above > > + description. An early, partial list of such hardware is: > > + an NVIDIA GPU >= Pascal, Mellanox IB >= mlx5, or an AMD GPU. > > Nevermind that the Nvidia support is stagaging and looks rather broken, > there is no Mellanox user of this either at this point. > > But either way this has no business in a common kconfig help. Just > drop the fine grained details and leave it to the overview. I disagree here. This explains what kind of hardware this is for (very new). Partial list does not hurt, and I know that I probably don't need to enable this. How else am I supposed to know if my computer needs page tables synchronized? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html