RFR: 8066444: Add CMS+ParNew support for promotion event

[Staffan Friberg]

Hi Marcus,

Not a Reviewer, but change looks good.

parNewGeneration.cpp
     255         if (obj != NULL && 
gc_tracer->should_report_promotion_in_new_plab_event()) {

     You could skip the NULL check as the allocated buffer should be 
large enough, but might be good to keep for clarity.


//Staffan

On 04/20/2015 05:51 AM, Marcus Larsson wrote:
> Hi,
>
> Please review the following patch to add PLAB tracing support for 
> CMS+ParNew GC. The patch is a slightly modified version of the 
> CMS+ParNew parts of Staffan Friberg's patch for JDK-8055845 [0]. With 
> the modifications, the GCTracer no longer needs to be passed around as 
> an argument, and can be fetched when the events are reported.
>
> I tried refactoring the change to avoid the need for the other two 
> added arguments as well, but since this code is part of a hot path I 
> found no way of doing this without introducing a performance regression.
>
> Webrev:
> http://cr.openjdk.java.net/~mlarsson/8066444/webrev.00/
>
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8066444
>
> Testing:
> local jtreg
>
> Thanks,
> Marcus
>
> [0]: 
> http://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2014-December/011477.html 
>