Conveners
Kernel Memory Management MC
- Matthew Wilcox (Oracle)
- David Hildenbrand (Red Hat)
Description
Memory management keeps on being exciting. With a lot of activity on all different kinds of projects, some more controversial subjects that might be worth discussing this year:
- Making Transparent Huge Pages more ... transparent (toggles, policies, khugepaged, ...)
- Making (m)THP/large folios a first-class citizen in MM
- What other improvements might we see from mTHP?
- Where to use eBPF in MM, and where not
- Ongoing challenges with memdescs (e.g., allocation/freeing/walking)
- How might we make allocations guaranteed to not fail?
- Which CXL use cases do we want to support, and how far should we go?
- Challenges with hypervisor live-update, and the integration into other subsystems (MM, drivers, etc)
- guest_memfd and the interaction with other MM subsystems (hugetlb, GUP, ...)
- Making hugetlb less weird
The "zombie memory cgroup" problem is a long-standing issue in the Linux Kernel. It occurs when a memory cgroup is destroyed by users, but kernel metadata cannot be freed because its Least Recently Used (LRU) pages, particularly shared file pages, remain charged to it. These pages can outlive the cgroup that originally owned them, acting as a permanent pin. In environments where cgroups are...
When device drivers reserve big blocks of MIGRATE_CMA pages, the underutilized MIGRATE_CMA can be used for MIGRATE_MOVABLE requests and these pages can be short-term pin for DMA, so if we require MIGRATE_CMA pages, the allocations might fail.
This topic has been discussed...
ABSTRACT
Enabling cgroup-level control over swap devices
PROPOSAL
In certain restricted environments, there is a technical requirement to use otherwise idle devices as extended swap memory - including remote storage systems accessible over the network. A motivating scenario is to configure background processes to use these slower network-backed swap devices, while foreground...