golang程序内存不断增长，但只有很小的inuse_space

Question

我有一个golang程序，定期运行一些例程。它的内存(顶部结果中的RSS)在一些服务器上持续增长，但在一些服务器上却没有增长。奇怪的是，RSS增长实例的pprof结果显示该进程只占用很少的inuse_space内存。

这是否意味着内存正在等待golang进行GC？但是48小时后，内存从26000kb增长到74000kb，我想golang自己应该已经做了好几次GC了。

我已经使用sync.Pool来避免频繁使用新的()对象。如何减少内存使用量？

下面是详细的数据，提前谢谢！

48小时内的RSS使用量(单位: kb)：

​

inuse_space：

(pprof) top
Showing nodes accounting for 1040.73kB, 100% of 1040.73kB total
      flat  flat%   sum%        cum   cum%
  524.09kB 50.36% 50.36%   524.09kB 50.36%  sp/audit.Coll
  516.64kB 49.64%   100%   516.64kB 49.64%  sp/audit.Coll.func2
         0     0%   100%   524.09kB 50.36%  sa/core.(*pr).run
         0     0%   100%   516.64kB 49.64%  sa/fw.(*Group).Go.func1
         0     0%   100%   516.64kB 49.64%  sp/audit/dis.(*Relay).Relay
         0     0%   100%   516.64kB 49.64%  sync.(*Pool).Get
(pprof) top -cum
Showing nodes accounting for 1040.73kB, 100% of 1040.73kB total
      flat  flat%   sum%        cum   cum%
         0     0%     0%   524.09kB 50.36%  sa/core.(*pr).run
  524.09kB 50.36% 50.36%   524.09kB 50.36%  sp/audit.Coll
         0     0% 50.36%   516.64kB 49.64%  sa/fw.(*Group).Go.func1
  516.64kB 49.64%   100%   516.64kB 49.64%  sp/audit.Coll.func2
         0     0%   100%   516.64kB 49.64%  sp/audit/dis.(*Relay).Relay
         0     0%   100%   516.64kB 49.64%  sync.(*Pool).Get

alloc_space：

Showing top 10 nodes out of 181
      flat  flat%   sum%        cum   cum%
 3306.19MB 25.83% 25.83%  3306.71MB 25.84%  io.copyBuffer
 1294.76MB 10.12% 35.95%  1386.15MB 10.83%  os.(*File).readdirnames
 1121.62MB  8.76% 44.71%  1121.62MB  8.76%  syscall.anyToSockaddr
  471.56MB  3.68% 48.40%   471.56MB  3.68%  net.newFD
  413.74MB  3.23% 51.63%   413.74MB  3.23%  bytes.makeSlice
  356.52MB  2.79% 54.41%   356.52MB  2.79%  github.com/go-xorm/xorm.(*Statement).Init
  261.55MB  2.04% 56.46%   309.05MB  2.41%  os.lstatNolog
  241.03MB  1.88% 58.34%   275.03MB  2.15%  os.Readlink
  236.51MB  1.85% 60.19%   236.51MB  1.85%  reflect.packEface
  230.51MB  1.80% 61.99%   230.51MB  1.80%  net.sockaddrToUnix
(pprof) top -cum
Showing nodes accounting for 3328.69MB, 26.01% of 12798.76MB total
Dropped 439 nodes (cum <= 63.99MB)
Showing top 10 nodes out of 181
      flat  flat%   sum%        cum   cum%
    6.50MB 0.051% 0.051%  6244.66MB 48.79%  sp/filesystem.walk
         0     0% 0.051%  6244.66MB 48.79%  sp/filesystem.walkProxy
         0     0% 0.051%  6088.14MB 47.57%  sa/fw.(*WorkerPool).StartWorker.func1
         0     0% 0.051%  5073.21MB 39.64%  sa/core.(*procRuntime).run
       1MB 0.0078% 0.059%  3446.69MB 26.93%  sp/filesystem.buildFileStat
       4MB 0.031%  0.09%  3431.67MB 26.81%  sp/filesystem.Chksum
         0     0%  0.09%  3334.15MB 26.05%  io.CopyN
         0     0%  0.09%  3306.71MB 25.84%  io.Copy
 3306.19MB 25.83% 25.92%  3306.71MB 25.84%  io.copyBuffer
      11MB 0.086% 26.01%  2659.24MB 20.78%  sa/fw.(*DBO).insertKeepOld

Answer 1

从1.12开始，go开始使用mode的无延迟MADV_FREE模式向操作系统释放内存。这不会在RSS中显示，除非系统上存在内存压力。要获得真正的用法，您必须查看RSS - LazyFree。这是在/proc中报告的。