RFR(S): 8025227: Add -XX: flag to print code cache sweeper statistics
tobi.hartmann at gmail.com
Fri Sep 27 07:39:49 PDT 2013
Chris, Vladimir, thank you for your reviews.
I followed your suggestions and added other useful statistics. The output
now looks like this:
Method flushing statistics:
Total sweep time: 152.649ms
Peak sweep time: 15.979ms
Peak sweep fraction time: 3.209ms
Total number of stack traversals: 25
Total number of flushed methods: 1320
Total size of flushed methods: 7188Kb
I did not include the other values, because as Vladimir already said, they
are removed by 8020151.
Here is the new webrev:
Thanks again for your review.
2013/9/27 Vladimir Kozlov <vladimir.kozlov at oracle.com>
> I agree with Chris, we are collecting those counters anyway. I also like
> Chris's idea about collecting freed sizes. Note, some counters will be
> removed by 8020151 changes:
> On 9/26/13 2:13 PM, Chris Plummer wrote:
>> Hi Tobias,
>> The one comment I would have is that the statistics you produce are all
>> timing related, but the option name implies you would get a bit more
>> than this. For example, maybe something like a count of the number of
>> methods flushed (and maybe total size). So I would suggest either rename
>> to PrintMethodFlushingTimingStati**stics (and also rename the print
>> method), or add some other useful statistics to the output. Probably all
>> the counters located below the " Stat counters" comment are good
>> best regards,
>> On 9/25/13 12:20 AM, Tobias Hartmann wrote:
>>> Please review the following small patch.
>>> I added the diagnostic VM option�**PrintMethodFlushingStatistics to
>>> print statistics about the NMethodSweeper (sweep times) on exit. This
>>> is useful to determine performance bottlenecks of applications that
>>> heavily compile code (e.g. nashorn).
>>> Thanks in advance!
>>> Best regards,
>>> By the way, I'm Tobias Hartmann, a student from Switzerland currently
>>> working on my Master Thesis "Code Cache Optimizations for Dynamically
>>> Compiled Languages" on supervision of Albert Noll.
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