RFR: 8179040: Avoid Ticks::now calls when EventClassLoad is not enabled
claes.redestad at oracle.com
Tue Apr 25 13:46:11 UTC 2017
thanks for reviewing and suggesting improvements offline!
On 04/25/2017 03:37 PM, Markus Gronlund wrote:
> Hi Claes,
> Looks good, thanks for fixing this.
> -----Original Message-----
> From: Claes Redestad
> Sent: den 25 april 2017 15:21
> To: hotspot-runtime-dev at openjdk.java.net
> Subject:  RFR: 8179040: Avoid Ticks::now calls when EventClassLoad is not enabled
> this patch removes calling Ticks::now when EventClassLoad isn't enabled, which has an effect on class loading performance:
> When tracing isn't enabled trace/tracing.hpp has dummy implementations which are easily optimized away by a compiler, which I've verified happens on linux OpenJDK builds with tracing disabled.
> On builds with tracing enabled then the changes means the call to get the time only happen if the event is enabled, which achieves the sought after startup optimization.
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