Only Kconfig and comments changes since since v2, git tree: https://cgit.freedesktop.org/~glisse/linux/log/?h=hmm-cdm-v3 Cache coherent device memory apply to architecture with system bus like CAPI or CCIX. Device connected to such system bus can expose their memory to the system and allow cache coherent access to it from the CPU. Even if for all intent and purposes device memory behave like regular memory, we still want to manage it in isolation from regular memory. Several reasons for that, first and foremost this memory is less reliable than regular memory if the device hangs because of invalid commands we can loose access to device memory. Second CPU access to this memory is expected to be slower than to regular memory. Third having random memory into device means that some of the bus bandwith wouldn't be available to the device but would be use by CPU access. This is why we want to manage such memory in isolation from regular memory. Kernel should not try to use this memory as last resort when running out of memory, at least for now. This patchset add a new type of ZONE_DEVICE memory (DEVICE_PUBLIC) that is use to represent CDM memory. This patchset build on top of the HMM patchset that already introduce a new type of ZONE_DEVICE memory for private device memory (see HMM patchset). The end result is that with this patch if a device is in use in a process you might have private anonymous memory or file back page memory using ZONE_DEVICE (MEMORY_PUBLIC). Thus care must be taken to not overwritte lru fields of such pages. Hence all core mm changes are done to address assumption that any process memory is back by a regular struct page that is part of the lru. ZONE_DEVICE page are not on the lru and the lru pointer of struct page are use to store device specific informations. Thus this patch update all code path that would make assumptions about lruness of a process page. patch 01 - consolidate naming of different device memory type patch 02 - deals with all the core mm functions patch 03 - add an helper to HMM for hotplug of CDM memory patch 04 - preparatory patch for memory controller changes patch 05 - update memory controller to properly handle ZONE_DEVICE pages when uncharging Previous posting: v1 https://lkml.org/lkml/2017/4/7/638 v2 https://lwn.net/Articles/725412/ Jérôme Glisse (5): mm/persistent-memory: match IORES_DESC name and enum memory_type one mm/device-public-memory: device memory cache coherent with CPU v2 mm/hmm: add new helper to hotplug CDM memory region mm/memcontrol: allow to uncharge page without using page->lru field mm/memcontrol: support MEMORY_DEVICE_PRIVATE and MEMORY_DEVICE_PUBLIC fs/proc/task_mmu.c | 2 +- include/linux/hmm.h | 7 +- include/linux/ioport.h | 1 + include/linux/memremap.h | 25 +++++- include/linux/mm.h | 16 ++-- kernel/memremap.c | 15 +++- mm/Kconfig | 11 +++ mm/gup.c | 7 ++ mm/hmm.c | 89 +++++++++++++++++-- mm/madvise.c | 2 +- mm/memcontrol.c | 226 ++++++++++++++++++++++++++++++----------------- mm/memory.c | 46 ++++++++-- mm/migrate.c | 60 ++++++++----- mm/swap.c | 11 +++ 14 files changed, 389 insertions(+), 129 deletions(-) -- 2.13.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
