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I'm not sure this will be the only system with this architecture. This is only the first one I know of. I hope it's not a one-off, after all the work we did on it. ;) The Linux kernel on this system is based on SLES. We are working with SUSE on backporting patches needed for this system. However, those patches need to be upstream first. DEVICE_PUBLIC was removed because it had no users. We're trying to add it (or something like it) back because we now have a use case for it. Regards,   Felix > >> Our nodes in the lab have .5 TB of >> system memory plus 256 GB of device memory split across 4 GPUs, all in >> the same coherent address space. Page migration is expected to improve >> application efficiency significantly. We will report empirical results >> as they become available. >> >> This includes patches originally by Ralph Campbell to change ZONE_DEVICE >> reference counting as requested in previous reviews of this patch series >> (see https://patchwork.freedesktop.org/series/90706/ We extended >> hmm_test to cover migration of MEMORY_DEVICE_COHERENT. This patch set >> builds on HMM and our SVM memory manager already merged in 5.14. >> We would like to complete review and merge this migration patchset for >> 5.16.