On Fri, Dec 15, 2023 at 10:40 AM Chris Li <chrisl@xxxxxxxxxx> wrote: > > On Thu, Dec 14, 2023 at 11:42 PM Fabian Deutsch <fdeutsch@xxxxxxxxxx> wrote:. > > > > > > Just to clarify, the "node" you mean the "node" in kubernetes sense, > > > which is the whole machine. In the Linux kernel MM context, the node > > > often refers to the NUMA memory node, that is not what you mean here, > > > right? > > > > Correct, I was referring to a kubernetes node, not numa node. > > > > > > > >> - With todays node level swap, and setting memory.swap.max=0 for all cgroups allows you toachieve a similar behavior (only opt-in cgroups will get swap). > > >> - the above approach however will still have a shared swap backend for all cgroups. > > > > > > Yes, the "memory.swap.tires" idea is trying to allow cgroups to select > > > a subset of the swap backend in a specific order. It is still in the > > > early stage of discussion. If you have any suggestion or feedback in > > > that direction, I am looking forward to hearing that. > > > > Interesting. There have been concerns to leak confidential data accidentally when it's getting written to a swap device. > > One common solution is to encrypt the data written to the device. If > someone gets hold of the swapped outed device without the key, they > can't get to the memory data without the key. Yes - I guess like writing it onto a dmcrypt device with some random key. Nevertheless, this was one of the topics. > > > > The other less discussed item was QoS for swap io traffic. > > > > At a first glance it seems like tires could help with the second use-case. > > The idea is that you can select the swap tiers list for each cgroup. > That way you can assign different swap QoS to different cgroup. Yes, it sounds like a fit. What use-cases did you have in mind for the tiers feature?
