RFR: 8290966: G1: Record number of PLAB filled and number of direct allocations

[Kim Barrett]

On Mon, 25 Jul 2022 14:11:24 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

> Hi all,
> 
>   for evaluation in [JDK-8288966](https://bugs.openjdk.org/browse/JDK-8288966) I added statistics output that show the amount of PLAB fills and direct allocations; I think this is useful for similar evaluations in the future, so I kept and split it out from that change. Adds these values to the existing JFR event too.
> 
> Testing: PLAB related tests, gha
> 
> Thanks,
>   Thomas

Looks good.  Just a couple whitespace comments.

src/hotspot/share/gc/shared/gcHeapSummary.hpp line 194:

> 192:   G1EvacSummary(size_t allocated, size_t wasted, size_t undo_wasted, size_t unused,
> 193:     size_t used, size_t region_end_waste, uint regions_filled, size_t num_plab_filled,
> 194:     size_t direct_allocated, size_t num_direct_allocated, size_t failure_used, size_t failure_waste) :

[pre-existing] Shouldn't these parameters be indented to the parameter list start?  As it is, it's hard to spot where the parameters end and the initializers start.

src/hotspot/share/gc/shared/gcHeapSummary.hpp line 197:

> 195:     _allocated(allocated), _wasted(wasted), _undo_wasted(undo_wasted), _unused(unused),
> 196:     _used(used),  _region_end_waste(region_end_waste), _regions_filled(regions_filled),
> 197:     _num_plab_filled(num_plab_filled), _direct_allocated(direct_allocated), _num_direct_allocated(num_direct_allocated),

Maybe another line break in this line, to keep it's length a bit more reasonable?

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Marked as reviewed by kbarrett (Reviewer).

PR: https://git.openjdk.org/jdk/pull/9626