RFR (S): Do more Full GC tries following the allocation failure

[Christine Flood]

I suppose three is the magic number...

This looks fine to me.

----- Original Message -----
> From: "Aleksey Shipilev" <shade at redhat.com>
> To: shenandoah-dev at openjdk.java.net
> Sent: Tuesday, December 13, 2016 8:23:19 AM
> Subject: RFR (S): Do more Full GC tries following the allocation failure
> 
> Hi,
> 
> There is another interesting race after full GC: if there are many threads
> alloc-failing and then requesting full GC, it might so happen that one of
> those
> threads unblocks after full GC, tries to allocate only to find other threads
> have claimed everything, fails, and that is OOME. While the better strategy
> should be another full GC.
> 
> See the change and the comment:
>   http://cr.openjdk.java.net/~shade/shenandoah/full-gc-retry/webrev.01/
> 
> Additionally, this gives us a tuning knob: with -XX:ShenandoahFullGCTries=0,
> we
> say that we would rather fail with OOME than accept the Full GC.
> 
> Testing: hotspot_gc_shenandoah, gc-bench alloc tests (where it OOMEd before)
> 
> Thanks,
> -Aleksey
> 
>