John Hubbard <jhubbard@xxxxxxxxxx> writes: > On 10/29/24 9:42 PM, Christoph Hellwig wrote: >> On Tue, Oct 29, 2024 at 09:39:15PM -0700, John Hubbard wrote: >>> I expect I could piece together something with Nouveau, given enough >>> time and help from Ben Skeggs and Danillo and all... >>> >>> Yes, this originated with the out of tree driver. But it never occurred >>> to me that upstream be uninterested in an obvious fix to an obvious >>> regression. >> Because pinning down these amounts of memoryt is completely insane. >> I don't mind the switch to kvmalloc, but we need to put in an upper >> bound of what can be pinned. > > I'm wondering though, how it is that we decide how much of the user's > system we prevent them from using? :) People with hardware accelerators > do not always have page fault capability, and yet these troublesome > users insist on stacking their system full of DRAM and then pointing > the accelerator to it. > > How would we choose a value? Memory sizes keep going up... The obvious answer is you let users decide. I did have a patch series to do that via a cgroup[1]. However I dropped that series mostly because I couldn't find any users of such a limit to provide feedback on how they would use it or how they wanted it to work. - Alistair [1] - https://lore.kernel.org/linux-mm/cover.c238416f0e82377b449846dbb2459ae9d7030c8e.1675669136.git-series.apopple@xxxxxxxxxx/ > thanks,
