Hi, Now on tiered memory system with different memory types, the reclaim path in shrink_page_list() already support demoting pages to slow memory node instead of discarding the pages. However, at that time the fast memory node memory wartermark is already tense, which will increase the memory allocation latency during page demotion. So a new method from user space demoting cold pages proactively will be more helpful. We can rely on the DAMON in user space to help to monitor the cold memory on fast memory node, and demote the cold pages to slow memory node proactively to keep the fast memory node in a healthy state. This patch set introduces a new scheme named DAMOS_DEMOTE to support this feature, and works well from my testing. Any comments are welcome. Thanks. Baolin Wang (2): mm: Export the alloc_demote_page() function mm/damon: Add a new scheme to support demotion on tiered memory system include/linux/damon.h | 3 + mm/damon/dbgfs.c | 1 + mm/damon/vaddr.c | 156 ++++++++++++++++++++++++++++++++++++++++++++++++++ mm/internal.h | 1 + mm/vmscan.c | 2 +- 5 files changed, 162 insertions(+), 1 deletion(-) -- 1.8.3.1
