Speakers
Ira Weiny
Jonathan Cameron
(Huawei Technologies R&D (UK))
Navneet singh
(Intel)
Description
CXL - Dynamic Capacity Devices (DCD)
CXL introduced Dynamic capacity device support in CXL 3.0 and 3.1. The feature
promises a lightweight memory hotplug feature which was designed to optimize
memory usage within data centers. The details of use cases for DCDs are still
playing out. Generally the use case is to reduce the cost of unused memory by
allowing for the dynamic allocation of memory.
Specific topics may include:
- The current status of the patch set as of the conference
- Use case discussion
- QoS support
- Interleaving support
- Including ndctl repercussions
(ignore different DC partition support for now) - Ideas for how to group extents
- By region tag
(does not work currently as regions are created in a
linear fashion with respect to the DPA of the device) - By dax device tag
(by assigning a tag value to dax devices which restrict
them to using only those extents with the same tag
value) - Shared memory challenges
- RDMA parallels
- kernel responsibilities
- flushing issues
- memfd to replace dax devices