On Mon, Jun 1, 2020 at 2:55 PM Michael Hall <mike(a)mjhall.org> wrote:
I joined this list because I'm interested in learning more about the specific
requirements and features of cloud images.
So I'm wondering what ZRAM adds or what problem ZRAM solves for a cloud image?
Simplest answer: better utilization of a limited resource, memory.
It does this by making it possible for the kernel to evict anonymous
pages. Therefore avoiding repetitive reclaiming of file pages when
under any sort of memory pressure. And it's faster than swap to disk.
And since it doesn't require a preallocation, if the workload were to
never need swap, it has a nearly zero cost. If you aren't using some
swap, aren't you in a sense overprovisioning memory?