What is GOMAXPROCS? Can an application use more cores than specified?
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Answer from AI
GOMAXPROCS is an environment variable or setting in Go that determines the maximum number of operating system threads (CPU cores) that the Go scheduler can use simultaneously to run goroutines.
By default, GOMAXPROCS is set to the number of available CPU cores, but it can be changed programmatically:
import "runtime"
runtime.GOMAXPROCS(4) // set maximum to 4 cores
If GOMAXPROCS is set to N, then the Go scheduler will use no more than N OS threads to run goroutines in parallel.
Can an application use more cores than specified?
No, within a single Go process, it will not use more cores than specified in GOMAXPROCS. However, if multiple processes are running, each with its own GOMAXPROCS, the total core usage can exceed the value in one process.
Thus, GOMAXPROCS limits parallelism within a Go process but does not restrict the system's overall core usage.