RFR: 8073545 - Use shorter and more descriptive names for GCworker threads

Bernd Eckenfels ecki at zusammenkunft.net
Thu Mar 5 11:45:24 UTC 2015


It would be good if all names contain "GC" maybe even have a Common prefix. (and a Common thread group in Java land, but that is I guess a different Topic)

-- 
http://bernd.eckenfels.net

----- Ursprüngliche Nachricht -----
Von: "Erik Helin" <erik.helin at oracle.com>
Gesendet: ‎05.‎03.‎2015 11:41
An: "Bengt Rutisson" <bengt.rutisson at oracle.com>
Cc: "hotspot-gc-dev at openjdk.java.net" <hotspot-gc-dev at openjdk.java.net>
Betreff: Re: RFR: 8073545 - Use shorter and more descriptive names for GCworker threads

On 2015-03-04, Bengt Rutisson wrote:
> 
> Hi David and everyone,
> 
> I don't have strong opinions on this, but here's what I'd suggest:
> 
> "CMSTask"
> "CMSMain"
> "G1ConcRefine#%d"
> "G1MarkTask"
> "G1ConcMark"
> "StringDedup"
> "ParGCTask"
> "GCParTask"
> 

These names looks good to me.

Thanks,
Erik

> 
> On 2015-03-04 15:11, David Lindholm wrote:
> >Hi Jesper,
> >
> >On 2015-03-04 14:52, Jesper Wilhelmsson wrote:
> >>Hi David,
> >>
> >>Thanks for fixing this!
> >>
> >>A couple of questions:
> >>
> >>-  set_name("G1 Concurrent Refinement Thread#%d", worker_id);
> >>+  set_name("G1 ConRefine#%d", worker_id);
> >>
> >>Is there any refinement threads that are not concurrent? If not, could
> >>we just call this "G1 Refine#%d" to simplify it slightly and remove an
> >>implementation detail that doesn't need to be exposed? This would also
> >>leave room for three digit numbers in case we have lots of these threads
> >>on some systems.
> >
> >I discussed this with Bengt, and his input was that Concurrent Refinement
> >is a well known concept in G1. I have no real opinion here, I'm fine with
> >both suggestions.
> >
> >>-  _parallel_workers = new FlexibleWorkGang("G1 Parallel Marking
> >>Threads",
> >>+  _parallel_workers = new FlexibleWorkGang("G1 Markers",
> >>
> >>Markers is cute, but could be misunderstood. Can we call it "G1 Mark
> >>Threads" instead?
> >
> >No, it is too long, the three last character with thread number won't fit
> >(#xx).
> >
> >>-  set_name("G1 Main Concurrent Mark GC Thread");
> >>+  set_name("G1 Main Marker");
> >>
> >>Again, "Marker" could be misunderstood. I don't have a good replacement
> >>though.
> >
> >I'm open for suggestions, but I think "G1 Main Marker" works.
> >
> >>-  set_name("GC task thread#%d (ParallelGC)", which);
> >>+  set_name("ParGC Thread#%d", which);
> >>
> >>I don't have a good suggestion for how to make this one character
> >>shorter, but currently there is only room for two digit numbers. Maybe
> >>just "GC Thread#%d". I don't think these threads will exist at the same
> >>time as any other GC threads anyway.
> >
> >With your suggestion these threads would be called the same thing as the
> >threads in sharedHeap. I think it is nice to quickly be able to see that
> >these threads indeed belongs to the ParallelGC.
> >
> >>-  set_name("Gang worker#%d (%s)", id, gang->name());
> >>+  set_name("%s#%d", gang->name(), id);
> >>
> >>Is there any limitation on the length of the name()? If it's too long
> >>the number won't show. Can we add an assert to make sure it isn't too
> >>long?
> >
> >I have gone through our current GangWorkers, and they fit. If you want I
> >can add an assert for <= 12 characters. OTOH it is not the end of the
> >world if we don't see the whole number in the debugger.
> >
> >
> >Thanks,
> >David
> >
> >>
> >>Thanks,
> >>/Jesper
> >>
> >>
> >>David Lindholm skrev den 4/3/15 13:48:
> >>>Hi,
> >>>
> >>>Please review this small fix which changes the names of the GC threads
> >>>to be
> >>>shorter and more descriptive. There is a limit on 16 characters
> >>>including the
> >>>terminating null byte for this name, since pthread_set_name_np() is
> >>>used. This
> >>>change will make it easier to debug, as these names shows up in the
> >>>debugger.
> >>>
> >>>Webrev: http://cr.openjdk.java.net/~brutisso/8073545/webrev.00/
> >>>Bug: https://bugs.openjdk.java.net/browse/JDK-8073545
> >>>
> >>>Testing: Passed JPRT.
> >>>
> >>>
> >>>Regards,
> >>>David
> >
> 
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