RFR: JDK-8061259: ParNew promotion failed is serialized on a lock

[Kim Barrett]

On Nov 10, 2014, at 6:04 PM, Kim Barrett <kim.barrett at oracle.com> wrote:
> 
> The proposed change modifies that behavior. Since the calling code
> seems to be going to some effort to deal with par_promote() returning
> NULL (indicating promotion failure) and keep going, it's not clear to
> me whether this behavioral change is desirable. And if it *is*
> desirable, it seems like a better place to do the short circuiting
> might be higher up the call chain, and possibly simplifying the
> handling of par_promote() returning NULL. Note that I've not yet
> investigated where such a higher point in the call chain might be.

If the behavioral change associated with the check at line 1358 *is*
desirable, then it looks to me as if it could / should be hoisted out
into the callers of par_promote(), where there is already a
_promotion_failed flag with associated accessor.  I think that
existing flag tracks the same state as the proposed new flag.  So the
callers of par_promote() could be responsible for suppressing those
calls based on the existing flag, rather than introducing a new flag.