Bug 1525983 Comment 12 Edit History

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(In reply to Paul Bone [:pbone] from comment #11)
> What do the last two columns measure, the time for nursery collections/major slices/elapsed time etc?  So I don't know which rows are good/bad.

The last two columns are average time per minor GC and total time spent in minor GC (note different units).

> Did you test with poisoning disabled?

Annoyingly I did not, so I've re-run the tests.  New results:

Path:               Major  Minor Average Average  Average  Total
                    Count  Count PR      nursery  time /uS time /mS
                                         size /MB
output-19-01-10.txt    117   266   21.6%       13     5123     1362
output-19-01-15.txt     56  3530    0.5%        1       51      180
output-19-01-20.txt     79  3451    0.6%        1       57      200
output-19-01-25.txt    103   253   21.1%       13     5551     1404
output-19-01-30.txt    111   268   22.1%       12     5038     1350
output-19-02-05.txt    140  3017    0.7%        1       61      185
output-19-02-10.txt    157  2735    0.6%        1       57      156
output-19-02-15.txt    149 14934    0.4%        1       20      312
output-19-02-20.txt    169   540    8.6%        6     1397      754
output-19-02-25.txt    155 13807    0.7%        1       21      298
output-19-02-28.txt    145 13355    0.3%        1       20      271

Observations:

1. It seems random whether or not it goes into the mode where we tenure more and use a larger nursery.  I don't think this is related to a change in the code -- in other words, it's still a problem.

2. Discounting runs where the above problem happened, builds from 19-02-15 with the smaller nursery size do ~4 times more minor GCs and spend ~50% more time in minor GC.
(In reply to Paul Bone [:pbone] from comment #11)
> What do the last two columns measure, the time for nursery collections/major slices/elapsed time etc?  So I don't know which rows are good/bad.

The last two columns are average time per minor GC and total time spent in minor GC (note different units).

> Did you test with poisoning disabled?

Annoyingly I did not, so I've re-run the tests.  New results:

```
Path:               Major  Minor Average Average  Average  Total
                    Count  Count PR      nursery  time /uS time /mS
                                         size /MB
output-19-01-10.txt    117   266   21.6%       13     5123     1362
output-19-01-15.txt     56  3530    0.5%        1       51      180
output-19-01-20.txt     79  3451    0.6%        1       57      200
output-19-01-25.txt    103   253   21.1%       13     5551     1404
output-19-01-30.txt    111   268   22.1%       12     5038     1350
output-19-02-05.txt    140  3017    0.7%        1       61      185
output-19-02-10.txt    157  2735    0.6%        1       57      156
output-19-02-15.txt    149 14934    0.4%        1       20      312
output-19-02-20.txt    169   540    8.6%        6     1397      754
output-19-02-25.txt    155 13807    0.7%        1       21      298
output-19-02-28.txt    145 13355    0.3%        1       20      271
```

Observations:

1. It seems random whether or not it goes into the mode where we tenure more and use a larger nursery.  I don't think this is related to a change in the code -- in other words, it's still a problem.

2. Discounting runs where the above problem happened, builds from 19-02-15 with the smaller nursery size do ~4 times more minor GCs and spend ~50% more time in minor GC.

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