On Wed, 22 Dec 2021 19:14:39 +0800 Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> wrote: > 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. This is interesting. I think it would be helpful if we could have some example scenarios in this changelog, help people understand how to use DAMOS_DEMOTE and what effects it has. Documentation/admin-guide/mm/damon/usage.rst would like an update? And the DAMON user space tool?
