Speaker
Pratyush Yadav
Description
Applications with large in-memory caches like databases or storage nodes suffer
heavily from downtime when upgrading the kernel. They need to go out of
commission not only for the reboot time, but also for the time it takes to warm
up the caches again. This talk proposes a mechanism that allows handing over
userspace memory to the next kernel after a kexec. This allows such applications
to persist their caches to achieve fast kernel upgrades with minimal downtime.
It can also be used with CRIU to avoid the need for modifying the applications
to use this mechanism. Other use cases include doing a "live update" for
container hosts, allowing kernel upgrades with low downtime for the container
workloads.