Is there a way to manage and tune the stop-the-world garbage collector in Go?

In Go, the garbage collector (GC) is stop-the-world, meaning all goroutines are paused for a short time during its operation. You can control and configure the GC using an environment variable or programmatically through the runtime package.

The main parameter for configuration is GOGC, which determines the heap growth threshold in percentage, after which garbage collection is triggered. By default, GOGC=100, which means GC runs when the heap size doubles.

Example of changing the GC threshold in code:

import "runtime"

func main() {
    // Set GC threshold to 200% (i.e., GC runs when heap size increases by 2 times)
    runtime.GOMAXPROCS(4) // for example, number of threads
    debug.SetGCPercent(200)
}

You can also use the runtime/debug package for more fine-tuned control:

import "runtime/debug"

func main() {
    debug.SetGCPercent(150) // change the GC trigger threshold
}

Additionally, you can manually trigger garbage collection via runtime.GC(), but this is rarely recommended.

Thus, the main way to control stop-the-world GC is by setting the GOGC threshold, which helps balance between collection frequency and pause times.