RFR: Verifier should avoid pushing on

[Zhengyu Gu]

Okay.

-Zhengyu


On 08/01/2017 01:34 PM, Aleksey Shipilev wrote:
> This little change cuts down testing time for about 30%:
>
> $ hg diff
> diff -r b514d97e3d24 src/share/vm/gc/shenandoah/shenandoahVerifier.cpp
> --- a/src/share/vm/gc/shenandoah/shenandoahVerifier.cpp	Tue Aug 01 17:33:56 2017 +0200
> +++ b/src/share/vm/gc/shenandoah/shenandoahVerifier.cpp	Tue Aug 01 19:26:00 2017 +0200
> @@ -607,12 +607,15 @@
>      oop obj = oop(addr);
>      cl.verify_oop_standalone(obj);
>
> -    // Verify everything reachable from that object too:
> -    stack.push(obj);
> +    // Verify everything reachable from that object too, hopefully realizing
> +    // everything was already marked, and never touching further:
> +    cl.verify_oops_from(obj);
> +    (*processed)++;
> +
>      while (!stack.is_empty()) {
> -      (*processed)++;
>        ShenandoahVerifierTask task = stack.pop();
>        cl.verify_oops_from(task.obj());
> +      (*processed)++;
>      }
>    }
>  };
>
> The reason is, doing the initial Stack.push() is costly when stack is empty, which it almost always is.
>
> Thanks,
> -Aleksey
>