Very nice write up.

Go’s focus on simplicity means that there is only a single parameter, SetGCPercent, which controls how much larger the heap is than the live objects within it.

FWIW, there is a new proposal from a member of the core Go team to add a second GC knob in the form of a soft limit on total memory:

https://github.com/golang/proposal/blob/master/design/48409-...

It includes some provisions to make sure that the application can keep making progress and avoid death spirals (part of the reason why it is a "soft" limit), and also includes some new GC-related telemetry.

From the blog write up, a second GC knob with a soft limit might have only been a minor help here, with the bigger wins coming from the code changes they described in the blog.