Request for review (S): 7161545: G1: Minor cleanups to the G1 logging

[Bengt Rutisson]

Hi everyone,

John had a look at this (Thanks!) but I still need one more review. Any 
takers?

http://cr.openjdk.java.net/~brutisso/7161545/webrev.01/

Bengt

On 2012-04-25 14:42, Bengt Rutisson wrote:
>
> Hi John,
>
> Thanks for looking at this!
>
> Here's an updated webrev based on your comments:
> http://cr.openjdk.java.net/~brutisso/7161545/webrev.01/
>
> I did not fix all of your comment. See my comments inline.
>
> On 2012-04-24 01:36, John Cuthbertson wrote:
>> Hi Bengt,
>>
>> This looks good to me. A couple of suggestions for your consideration:
>>
>> * Looking at the code, it occurred to me that 
>> G1CollectorPolicy::print_par_stats() and 
>> G1CollectorPolicy::print_par_sizes()  are very similar. If you passed 
>> the format string in as a parameter and permitted the order in 
>> print_par_sizes() to match that in print_par_stats() (which it 
>> probably should) then they could be coalesced into a single routine 
>> (or a base routine and two callers).
>
> It is not really enough to just pass the format string since we also 
> need to cast the values. Also, it is kind of strange to me to have the 
> format string specified in one place and passing values to it in 
> another place.
>
> However, you are definitely correct about the code duplication. I 
> tried a different solution and added a parameter to the 
> print_par_stats() to allow it to choose between the two format 
> strings. What do you think about that?
>
>> * Did you consider extending the current version of 
>> G1CollectorPolicy::print_stats() to take an additional, optional 
>> (with a default value of NULL) extra_info parameter?
>
> Don't think this adds much value. The print_stats() methods are one 
> liners so I don't think the code would be much simpler by doing this.
>
>> * Shouldn't 'workers' be an unsigned? Simlarly for no_of_gc_threads 
>> (parameter and field of G1CollectorPolicy), and active_workers at the 
>> call site of G1CollectorPolicy::record_collection_pause_end()?
>
> You are right, but g1CollectorPolicy is full of "int workers" so I 
> don't think we should change that as part of this checkin. Should I 
> file a separate CR to change all occurrences of "int workers" to "uint 
> workers" in g1CollectorPolicy?
>
>> * Did you consider templatizing bytesize_in_proper_unit()?
>
> Good idea! I did that.
>
> Thanks again for looking at this!
> Bengt
>
>
>>
>> JohnC
>>
>> On 04/16/12 02:32, Bengt Rutisson wrote:
>>>
>>> Hi all,
>>>
>>> Could I have a couple of reviews for this?
>>> http://cr.openjdk.java.net/~brutisso/7161545/webrev.00
>>>
>>> This includes four minor cleanups of the G1 logging:
>>>
>>> * Rename "to-space-overflow" to "to-space-exhausted"
>>> * Introduce one decimal point in the size format
>>> * Add Sum to the aggregate and re-order the entries
>>> * Add number of GC workers to the log output
>>>
>>> I also added gigabyte conversion to proper_unit_for_byte_size() and 
>>> byte_size_in_proper_unit(). I hope that makes sense. It is not 
>>> strictly necessary for this change, but I think it makes sense. I'm 
>>> fine with leaving it out or pushing it as a separate change.
>>>
>>>
>>> After the change logging on the finest level will look like this:
>>>
>>> [GC pause (young), 0.00447433 secs]
>>>    [Parallel Time: 3.3 ms, GC Workers: 4]
>>>       [GC Worker Start (ms):  31098.2  31098.2  31098.3  31098.3
>>>        Min: 31098.2, Avg: 31098.2, Max: 31098.3, Diff: 0.1, Sum: 
>>> 124392.9]
>>>       [Ext Root Scanning (ms):  2.2  2.4  2.0  2.5
>>>        Min: 2.0, Avg: 2.3, Max: 2.5, Diff: 0.6, Sum: 9.1]
>>>       [Update RS (ms):  0.2  0.0  0.3  0.0
>>>        Min: 0.0, Avg: 0.1, Max: 0.3, Diff: 0.3, Sum: 0.5]
>>>          [Processed Buffers : 1 0 4 0
>>>           Sum: 5, Avg: 1, Min: 0, Max: 4, Diff: 4]
>>>       [Scan RS (ms):  0.1  0.1  0.2  0.0
>>>        Min: 0.0, Avg: 0.1, Max: 0.2, Diff: 0.2, Sum: 0.3]
>>>       [Object Copy (ms):  0.7  0.7  0.6  0.5
>>>        Min: 0.5, Avg: 0.6, Max: 0.7, Diff: 0.2, Sum: 2.5]
>>>       [Termination (ms):  0.0  0.0  0.0  0.0
>>>        Min: 0.0, Avg: 0.0, Max: 0.0, Diff: 0.0, Sum: 0.0]
>>>          [Termination Attempts : 1 1 1 1
>>>           Sum: 4, Avg: 1, Min: 1, Max: 1, Diff: 0]
>>>       [GC Worker Other (ms):  0.1  0.0  0.1  0.1
>>>        Min: 0.0, Avg: 0.1, Max: 0.1, Diff: 0.0, Sum: 0.2]
>>>       [GC Worker Total (ms):  3.2  3.2  3.2  3.1
>>>        Min: 3.1, Avg: 3.2, Max: 3.2, Diff: 0.1, Sum: 12.7]
>>>       [GC Worker End (ms):  31101.4  31101.4  31101.4  31101.4
>>>        Min: 31101.4, Avg: 31101.4, Max: 31101.4, Diff: 0.0, Sum: 
>>> 124405.6]
>>>    [Code Root Fixup: 0.0 ms]
>>>    [Clear CT: 0.1 ms]
>>>    [Cur Clear CC: 0.0 ms]
>>>    [Cum Clear CC: 0.1 ms]
>>>    [Min Clear CC: 0.0 ms]
>>>    [Max Clear CC: 0.0 ms]
>>>    [Avg Clear CC: 0.0 ms]
>>>    [Other: 1.1 ms]
>>>       [Choose CSet: 0.0 ms]
>>>       [Ref Proc: 0.1 ms]
>>>       [Ref Enq: 0.0 ms]
>>>       [Free CSet: 0.6 ms]
>>>    [Eden: 79.0M(79.0M)->0.0B(79.0M) Survivors: 1024.0K->1024.0K 
>>> Heap: 80.2M(100.0M)->1261.0K(100.0M)]
>>>  [Times: user=0.06 sys=0.00, real=0.04 secs]
>>>
>>>
>>> Thanks,
>>> Bengt
>>
>