[10] RFR: 8179040: Avoid Ticks::now calls when EventClassLoad is not enabled

[Erik Helin]

Hey Claes,

On 04/25/2017 03:21 PM, Claes Redestad wrote:
> Hi,
>
> this patch removes calling Ticks::now when EventClassLoad isn't enabled,
> which
> has an effect on class loading performance:
>
> http://cr.openjdk.java.net/~redestad/8179040/hotspot.01/

looks good, Reviewed.

> 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.

Sounds great, thanks for fixing this.

Erik

> Thanks!
>
> /Claes