Request for review (S): 7161545: G1: Minor cleanups to the G1 logging
john.cuthbertson at oracle.com
Thu Apr 26 14:47:32 PDT 2012
Thanks for making the changes - looks good to me. And converting
no_of_workers etc to an unsigned as a separate CR is fine.
On 04/25/12 05:42, Bengt Rutisson wrote:
> Hi John,
> Thanks for looking at this!
> Here's an updated webrev based on your comments:
> 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!
>> On 04/16/12 02:32, Bengt Rutisson wrote:
>>> Hi all,
>>> Could I have a couple of reviews for this?
>>> 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:
>>> [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:
>>> [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]
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