hang when using -XX:-UseCompilerSafepoints

[Aleksey Shipilev]

On 13.11.2014 02:38, Vladimir Kozlov wrote:
> On 11/12/14 12:13 PM, Aleksey Shipilev wrote:
>> Still not sure if this is a runtime bug: stripping safepoints from the
>> non-counted loop seems to be a recipe for disaster.
> 
> This flag does not affect compiled code - so it is not compiler issue.
> It is only used in runtime/safepoint.cpp and it guards the code which
> protects a polling page.
> 
> There are many bugs which shows current problem. For example:
> 
> https://bugs.openjdk.java.net/browse/JDK-6873333
> 
> I would say that we have to remove it or at least make it experimental
> flag if we want to do experiments with it.
> 
> We definitely should not allow to use it in production!

Yes, that's what I meant. By "runtime" I meant JRE as whole, not a
particular component. I am not sure why Tom played with this flag to
begin with, are there legitimate use cases that force users to mess with
safepoint internals? I sure hope there are no such use cases.

I agree that demoting this flag from "product" to "experimental" sets
the expectations about its impact right.

Thanks,
-Aleksey.