golang gc 这种情况是否是需要优化内存？

Time: Jan 13, 2018 at 11:14am (CST)
Duration: 30.11s, Total samples = 12.17s (40.41%)
Entering interactive mode (type "help" for commands, "o" for options)
(pprof) top
Showing nodes accounting for 6170ms, 50.70% of 12170ms total
Dropped 281 nodes (cum <= 60.85ms)
Showing top 10 nodes out of 170
      flat  flat%   sum%        cum   cum%
    1370ms 11.26% 11.26%     1370ms 11.26%  runtime.futex /usr/local/go/src/runtime/sys_linux_amd64.s
    1310ms 10.76% 22.02%     2960ms 24.32%  runtime.scanobject /usr/local/go/src/runtime/mgcmark.go
     880ms  7.23% 29.25%      880ms  7.23%  runtime.heapBitsForObject /usr/local/go/src/runtime/mbitmap.go
     480ms  3.94% 33.20%      480ms  3.94%  runtime.usleep /usr/local/go/src/runtime/sys_linux_amd64.s
     420ms  3.45% 36.65%      420ms  3.45%  runtime.greyobject /usr/local/go/src/runtime/mgcmark.go
     410ms  3.37% 40.02%      420ms  3.45%  runtime.mapiternext /usr/local/go/src/runtime/hashmap.go
     390ms  3.20% 43.22%     1330ms 10.93%  runtime.mapassign_faststr /usr/local/go/src/runtime/hashmap_fast.go
     330ms  2.71% 45.93%      660ms  5.42%  runtime.makemap /usr/local/go/src/runtime/hashmap.go
     300ms  2.47% 48.40%      310ms  2.55%  syscall.Syscall /usr/local/go/src/syscall/asm_linux_amd64.s
     280ms  2.30% 50.70%      500ms  4.11%  runtime.selectgo /usr/local/go/src/runtime/select.go

看着 cpu 最高的都是scanobject

请教下，谢谢