RFR(S): Merge GC thread pools

[Roman Kennke]

Am Montag, den 13.02.2017, 15:28 -0500 schrieb Zhengyu Gu:
> On 02/13/2017 03:20 PM, Roman Kennke wrote:
> 
> > For mark-compact, you setup workers once for marking and then again
> > for
> > the rest? Any specific reason for that? Else I think it should be
> > set
> > up once for everything in mark-compact.
> 
> The rest phases are proportional to live set size, which is obtained
> after marking.
> 
> Maybe I missed something, what other factors should be considered for
> phase 2, 3, and 4?

Maybe I don't understand all of it yet.

To me it looks like you calculate num-threads for init-marking, which
is meant for scanning roots real quick. But then it's used for marking
all the heap, which is, as you say, LDS-size dependend. I would throw a
generous number of threads on it. ;-)

Roman

> 
> Thanks,
> 
> -Zhengyu
> 
> 
> > Roman
> > 
> > Am Montag, den 13.02.2017, 15:05 -0500 schrieb Zhengyu Gu:
> > > This is the revised webrev that contains further clean up for
> > > UseDynamicNumberOfGCThreads support.
> > > 
> > > Now, the calculation of the number of workers for each GC phase
> > > is
> > > moved up to the top of the phase.
> > > Once setup, it expects all sub-routines are used active_workers
> > > for
> > > the GC tasks.
> > > 
> > > ConcGCThreads and ParallelGCThreads are still honored via.
> > > ShenandoahCollectorPolicy::calc_xxxx() methods.
> > > 
> > > 
> > > Webrev: http://cr.openjdk.java.net/~zgu/shenandoah/single-worker/
> > > webr
> > > ev.01/
> > > 
> > > 
> > > Thanks,
> > > 
> > > -Zhengyu
> > > 
> > > 
> > > 
> > > On 02/13/2017 10:22 AM, Zhengyu Gu wrote:
> > > > I intended to update workers calculation in followup patch.
> > > > 
> > > > You are right, without that changes, this messes up
> > > > conc/parallel
> > > > workers.
> > > > 
> > > > I will combine the two patches, and update the webrev later.
> > > > 
> > > > Thanks,
> > > > 
> > > > -Zhengyu
> > > > 
> > > > 
> > > > 
> > > > On 02/11/2017 02:55 AM, Aleksey Shipilev wrote:
> > > > > On 02/10/2017 09:37 PM, Zhengyu Gu wrote:
> > > > > > http://cr.openjdk.java.net/~zgu/shenandoah/single-worker/we
> > > > > > brev
> > > > > > .00/
> > > > > 
> > > > > I was thinking that after this merge, we can still use
> > > > > ParallelGCThreads and
> > > > > ConcCGThreads to limit parallelism of concurrent and parallel
> > > > > phases.
> > > > > Is this
> > > > > handled now?
> > > > > 
> > > > > Thanks,
> > > > > -Aleksey
> > > > > 
> 
>