Open Source Summit + Embedded Linux Conference Europe 2020

When the hypervisor assigns memory to one virtual machine with pass-through devices, it needs to pin the memory first. As you know, "pin memory" is one time-consuming work which is directly proportional to the amount of memory. If you just assign 8GB RAM to VM, that might be not a case at all, but that must be one big problem if the RAM is 300GB, the only "pin memory" process need more than 60s. 300G is one common configuration in the cloud, and 60s impacts the user experience seriously. This topic will present one simple solution for accelerating the boot process with virtio-balloon, then the hypervisor can pin the memory asynchronously. This whole process runs in the background with little user perception what can bring very good user experience. This solution could reduce around 90 percents boot-time compared with one normal use case.