Question

任何人都可以解释一下，G1收藏家如何确定年轻地区的数量？ G1论文指出，＆＃34;我们通过历史平均跟踪完全年轻收藏的固定和每个地区的成本，并使用这些估计来确定在完全年轻的疏散停顿之间分配的年轻地区的数量＆＃34;但没有细节。

例如，给定以下GC日志，预测的年轻区域时间意味着什么以及如何计算？伊甸园和幸存者如何计算？

    2015-12-30T08:04:21.124+0000: 10.424: [GC pause (young) 10.424: [G1Ergonomics (CSet Construction) start choosing CSet, _pending_cards: 281, predicted base time: 17.05 ms, remaining time: 182.95 ms, target pause time: 200.00 ms]
 10.424: [G1Ergonomics (CSet Construction) add young regions to CSet, eden: 155 regions, survivors: 5 regions, predicted young region time: 7335.19 ms]
 10.424: [G1Ergonomics (CSet Construction) finish choosing CSet, eden: 155 regions, survivors: 5 regions, old: 0 regions, predicted pause time: 7352.24 ms, target pause time: 200.00 ms]
2015-12-30T08:04:21.171+0000: 10.472: [SoftReference, 0 refs, 0.0000490 secs]2015-12-30T08:04:21.172+0000: 10.472: [WeakReference, 617 refs, 0.0000780 secs]2015-12-30T08:04:21.172+0000: 10.472: [FinalReference, 360 refs, 0.0004730 secs]2015-12-30T08:04:21.172+0000: 10.472: [PhantomReference, 1 refs, 45 refs, 0.0000210 secs]2015-12-30T08:04:21.172+0000: 10.472: [JNI Weak Reference, 0.0000120 secs], 0.0494460 secs]
   [Parallel Time: 47.1 ms, GC Workers: 13]
      [GC Worker Start (ms): Min: 10424.3, Avg: 10424.4, Max: 10424.5, Diff: 0.2]
      [Ext Root Scanning (ms): Min: 1.2, Avg: 1.6, Max: 2.0, Diff: 0.8, Sum: 21.2]
      [Update RS (ms): Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.0]
         [Processed Buffers: Min: 0, Avg: 0.6, Max: 8, Diff: 8, Sum: 8]
      [Scan RS (ms): Min: 0.0, Avg: 0.0, Max: 0.3, Diff: 0.2, Sum: 0.5]
      [Code Root Scanning (ms): Min: 0.0, Avg: 0.0, Max: 0.3, Diff: 0.3, Sum: 0.3]
      [Object Copy (ms): Min: 44.4, Avg: 44.7, Max: 45.0, Diff: 0.6, Sum: 581.5]
      [Termination (ms): Min: 0.0, Avg: 0.2, Max: 0.3, Diff: 0.3, Sum: 3.0]
      [GC Worker Other (ms): Min: 0.0, Avg: 0.0, Max: 0.1, Diff: 0.1, Sum: 0.4]
      [GC Worker Total (ms): Min: 46.5, Avg: 46.7, Max: 46.8, Diff: 0.2, Sum: 606.9]
      [GC Worker End (ms): Min: 10471.1, Avg: 10471.1, Max: 10471.1, Diff: 0.1]
   [Code Root Fixup: 0.1 ms]
   [Code Root Migration: 0.3 ms]
   [Clear CT: 0.5 ms]
   [Other: 1.5 ms]
      [Choose CSet: 0.0 ms]
      [Ref Proc: 1.1 ms]
      [Ref Enq: 0.0 ms]
      [Free CSet: 0.3 ms]
   [Eden: 4960.0M(4960.0M)->0.0B(4800.0M) Survivors: 160.0M->320.0M Heap: 5142.0M(100.0G)->345.4M(100.0G)]
 [Times: user=0.60 sys=0.01, real=0.05 secs]

如何通过G1确定年轻地区的数量？

0 个答案: