util/ring: TestRingBuffer takes unreasonably long time

[yuzefovich]

From #65045 (comment):

TestRingBuffer - 55.76s

We should investigate why it is so and make it faster. Also see #63388 - hopefully we can revert that change too.

[XuanYang-cn]

t.Parallel will help a bit.

On my machine, the test takes 11.41s, ok example.com/ring 11.241s

If add t.Parallel

 func TestRingBufferA(t *testing.T) {                                                                             
     t.Parallel()                                                                                                 
      for count := 1; count <= maxCount; count++ {                                                                 
         t.Run("Parallel", func(t *testing.T) {                                                                   
             t.Parallel()                                                                                         
             testRingBuffer(t, count)                                                                                        
         })                                                                                                       
      }                                                                                                            
  }  

The test takes 7.89s, ok example.com/ring 7.897s, about 30% speedup.

[yuzefovich]

@XuanYang-cn thanks for looking into this! I agree, running the subtests in parallel is a good idea. I think it'd be reasonable to reduce the number of runs (i.e. maxCount) from 1000 maybe to 100. Do you wanna open a PR for these two ideas? I'll assign the issue to you for now.

[XuanYang-cn]

@yuzefovich OK，I'll open a pr