Request for reviews (S): 6916062: assert(_inserts <= _insert_limit, "hash table overflow") in NodeHash::hash_insert

[Tom Rodriguez]

That seems fine for a backport.  Maybe we should consider some product level code to bailout if we do too many rounds of IGVN?

tom

On Sep 28, 2010, at 7:08 PM, Vladimir Kozlov wrote:

> http://cr.openjdk.java.net/~kvn/6916062/webrev.02
> 
> Fixed 6916062: assert(_inserts <= _insert_limit,"hash table overflow") in NodeHash::hash_insert
> 
> Changes for 6711117 put a memory node back on IGVN
> worklist if address type does not match cached type
> in a hope that address nodes will be processed and
> the type will be updated. But it does not check that
> there are nodes on worklist which will trigger address
> processing. As result the memory node is pulled from
> and pushed on IGVN worklist infinitely.
> On each iteration NodeHash::_inserts value is incremented
> forcing hash table grow until integer value NodeHash::_max
> is overflow (became 0) which triggers bug's assert.
> 
> I decided to go with simplest fix which is easy to backport
> and leave fixing address type inconsistency for later
> (I have bug 6715629).
> I also added asserts to catch such situations.
> 
> Tested with failing case, CTW, JPRT.