Alexey Avramov

Info: Switching off a swapspace (on HDD if it was not empty) can cause a significant increasing PSI value (I've seen `some avg10` = 70 when ran `swapoff -a`).

The maximum PSI values depend on the type of swapspace. 99 for slow HDD, 60-70 for zram and SSD. Not very long-term exceedances are normal. Only long-term threshold exceedances are...

@rfjakob see https://www.kernel.org/doc/html/latest/accounting/psi.html#monitoring-for-pressure-thresholds and https://www.kernel.org/doc/html/latest/accounting/psi.html#userspace-monitor-usage-example (using poll() since Linux 5.2) >Users can register triggers and use poll() to be woken up when resource pressure exceeds certain thresholds

>PSI is such a headache Only on desktops. But don't worry, rfjakob-sensei: PSI should be very useful for servers. Disable PSI by default, add warnings to the documentation, and PSI...

>muqss is interacting badly with PSI No. >Do you use also btrfs? See https://bugzilla.kernel.org/show_bug.cgi?id=196729 https://github.com/hakavlad/nohang/issues/25#issuecomment-523226166 >Yes, I do. Seems like this problem was with swap on btrfs.

>users with other filesystems other than BTRFS claiming they are experiencing the same/similar problems. Could you provide links, please?

>PSI relies on cgroups support PSI is not directly dependent on сgroups. PSI provides metrics for each group with cgroup_v2. Without cgroup_v2 PSI works well and provides files only in...

It's time to use PSI metrics to improve interactivity. In this post I want to tell you about psi2log and psi-top scripts from nohang package. These simple tools can help...

I offer you to add optional PSI support. For example, earlyoom --psi some,40. What this should mean? If -m threshold exceeded, we can shoot if memory some avg10 > 40....

nohang with PSI: no problem: https://www.youtube.com/watch?v=Y6GJqFE_ke4