Srinivasulu Thanneeru <sthanneeru.opensrc@xxxxxxxxxx> writes: > On 12/4/2023 9:13 PM, Michal Hocko wrote: >> CAUTION: EXTERNAL EMAIL. Do not click links or open attachments >> unless you recognize the sender and were expecting this message. >> On Fri 01-12-23 03:34:20, sthanneeru.opensrc@xxxxxxxxxx wrote: >>> From: Srinivasulu Thanneeru <sthanneeru.opensrc@xxxxxxxxxx> >>> >>> The memory tiers feature allows nodes with similar memory types >>> or performance characteristics to be grouped together in a >>> memory tier. However, there is currently no provision for >>> moving a node from one tier to another on demand. >> Could you expand on why this is really needed/necessary? What is the >> actual usecase? > > Hi Michal Hock, > > Following two use-cases we have observed. > 1. It is not accurate to group similar memory types in the same tier, > because even similar memory types may have different speed grades. > > 2. Some systems boots up with CXL devices and DRAM on the same > memory-tier, we need a way to move the CXL nodes to the correct tier > from the user space. I guess that you need to move all NUMA nodes with same performance metrics together? If so, That is why we previously proposed to place the knob in "memory_type". -- Best Regards, Huang, Ying