Question

过多指针导致垃圾回收太慢。

package main

import (
	"runtime"
)

func main() {
	a := make([]*int, 1e9)

	for i := 0; i < 10; i++ {
		runtime.GC()
	}

	runtime.KeepAlive(a)
}

$ go build -o test && GODEBUG=gctrace=1 ./test

gc 1 @0.916s 21%: 0.014+5293+0.003 ms clock, 0.059+0/5293/15864+0.012 ms cpu, 7629->7629->7629 MB, 7630 MB goal, 4 P (forced)
gc 2 @6.210s 23%: 0.009+7394+0.047 ms clock, 0.038+0/7394/22174+0.18 ms cpu, 7629->7629->7629 MB, 15258 MB goal, 4 P (forced)

换成 uintptr 会将 GC 占比从 20% 回落到 0.1%。