Trim support is standard. Any kernel released in the past 15 years or so will have trim support built in. So that’s not something you should worry about.
How trimming is triggered is another matter, and is distro dependent. On Arch and Debian at least there is a weekly systemd timer that runs the fstrim command on all trimmable filesystems. You can check it if’s enabled with: systemctl list-unit-files fstrim.timer. I can’t tell how other distributions handle that. On Debian derived ones, I imagine it’s similar, on something like Slackware, which is systemd-less and more hands-off in its approach, you may have to schedule fstrim yourself, or run it manually occasionally.
There is also the discard mount option that you can add in /etc/fstab, which enables automatic synchronous trimming every time blocks are deleted, but its use is discouraged because it carries a performance penalty.
Hope that answers your question.
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