That's low utilization. If your ram was fully used and stuff was being frequently stopped, that's when I would be concerned (and when you would experience wear on your SSD).

Right now you have less than a quarter used, and a couple things the kernel decided to swap out. Perfectly normal.

I disagree with most here.

You need to reduce swappiness even more, and tweak some other variables (like the memory “threshold” Linux starts to swap, and disk cache aggressiveness) to stop Linux from swapping so opportunistically under such a light load.

IMO, Linux is configured for “old” systems by default: slow HDDs, and constrained RAM pools, where disk IO really, really needs caching, and where idle background processes take a large fraction of RAM.

You have superfluous RAM for your workload. And very fast disk IO that isn’t such a hindrance to apps anyway. And a disk you don’t want to wear. This is the opposite scenario: you don’t want Linux to swap unless it absolutely has to.

For reference, this is part of my config. It’s rather niche and you probably shouldn’t use it, but you should consider looking up the variables:

'''

Keep min reserve reasonable for 8GB usable space

vm.min_free_kbytes = 262144 # Lower absolute minimum to 256MB

vm.watermark_scale_factor = 10 # Lower to 0.1% (which is ~128MB on 128GB)

Disable watermark boosting completely

vm.watermark_boost_factor = 0

Normal-ish metadata pressure so desktop doesn't stutter on disk reads

vm.vfs_cache_pressure = 120

Allow reasonable swapping of inactive anonymous desktop pages, could be lower

vm.swappiness = 10

Dirty bytes limits to limit caching

vm.dirty_background_bytes = 67108864 vm.dirty_bytes = 268435456

Disable compaction & proactive scans to stop freezing with large portions of RAM blocked

vm.compaction_proactiveness = 0 vm.compact_unevictable_allowed = 0

vm.page-cluster = 0 # 4kb pages for SSD '''

It makes a night-and-day difference for some workloads on my system, that would otherwise swap pointlessly, just tank performance and even de-stabilize the system.

The amount of swap used is not a good indicative, you need to check if there is a big exchange of data per second/minute. This is the only indicative of an out of memory system.

Sometimes, some regions of data memory "age" in ram without any access for a long periods of time, the the kernel here has two options, it could destroy the region knowing it could recreate it when needed (with some cpu overhead) or moved this to a swap file when the ram structure already in the swap file and release than section.

Which regions are good candidates for this? Buffers, specially in the fs, code region used for processes or even data sections of a long sleeping process...

Checking your data, if those 5gb are created over a long period of time I would not care a lot about it. Remeber how big the swap is, isn't that important vs real traffic (in or out) to it

You can enable zram and remove your on disk swap file if you prefer to spare the SSD write cycles....

Yeah that's completely normal, looks absolutely fine to me. For more info on how linux uses memory I suggest reading https://www.linuxatemyram.com/

To add: that link suggests looking if your swap usage is changing. Linux is quite happy to stuff some memory that isn't actually used in swap. If it was right about it not being used you should see the swap usage not changing much, so your SSD isn't really being used either apart from the initial swap-out. If your swap usage keeps fluctuating wildly there is more going on which might warrant further investigation.

Huh....

  System load:  1.26                Temperature:           57.0 C
  Usage of /:   20.4% of 454.86GB   Processes:             527
  Memory usage: 44%                 Users logged in:       1
  Swap usage:   0%                  IPv4 address for eno1: 192.168.1.190

Ubuntu 22.04.5 - 32 GB RAM - 53 total containers

cat /proc/sys/vm/swappiness: 60 (pretty much default)

cat /proc/pressure/cpu: some avg10=0.68 avg60=0.62 avg300=0.67 total=960097774
full avg10=0.00 avg60=0.00 avg300=0.00 total=0
cat /proc/pressure/memory: some avg10=0.00 avg60=0.00 avg300=0.00 total=0
full avg10=0.00 avg60=0.00 avg300=0.00 total=0
cat /proc/pressure/io: some avg10=1.16 avg60=4.88 avg300=3.85 total=2831425045
full avg10=1.11 avg60=4.54 avg300=3.58 total=2653626377