RFR(M): 8166317: InterpreterCodeSize should be computed

[Volker Simonis]

Hi Vladimir,

that's a good suggestion! I've did so and prepared a new webrev:

http://cr.openjdk.java.net/~simonis/webrevs/2017/8166317.v4/

I've also verified that:

http://cr.openjdk.java.net/~simonis/webrevs/2017/8187091.v2/

still applies after 8166317.v4

Thank you and best regards,
Volker


On Tue, Oct 17, 2017 at 7:49 PM, Vladimir Kozlov
<vladimir.kozlov at oracle.com> wrote:
> Hi, Volker
>
> You can do a trick with NOT_SPARC() macro to avoid defining empty method on
> all platforms:
>
> +#if INCLUDE_ALL_GCS
> +void g1_barrier_stubs_init() NOT_SPARC( {} );  // depends on universe_init,
> must be before interpreter_init
> +#endif
>
> I thought we pushed 8187091 already. I will keep it in mind.
>
> Thanks,
> Vladimir
>
>
> On 10/10/17 10:17 AM, Volker Simonis wrote:
>>
>> On Tue, Oct 10, 2017 at 9:42 AM, Andrew Haley <aph at redhat.com> wrote:
>>>
>>> On 09/10/17 20:24, Volker Simonis wrote:
>>>>
>>>> Unfortunately we can't easily generate these stubs during
>>>> 'stubRoutines_init1()' because
>>>> 'generate_dirty_card_log_enqueue_if_necessary()' needs the byte map
>>>> base address which is only initialized in
>>>> 'CardTableModRefBS::initialize()' during 'univers_init()' which
>>>> happens after 'stubRoutines_init1()'.
>>>
>>>
>>> Yes you can, you can do something like we do for narrow_ptrs_base:
>>>
>>>      if (Universe::is_fully_initialized()) {
>>>        mov(rheapbase, Universe::narrow_ptrs_base());
>>>      } else {
>>>        lea(rheapbase,
>>> ExternalAddress((address)Universe::narrow_ptrs_base_addr()));
>>>        ldr(rheapbase, Address(rheapbase));
>>>      }
>>>
>>
>> Hi Andrew,
>>
>> thanks for your suggestion. Yes, I could do that, but that would
>> replace a constant load in the barrier with a constant load plus a
>> load from memory, because during stubRoutines_init1() heap won't be
>> initialized. Not sure about this, but I think we want to avoid this
>> overhead in the barriers.
>>
>> Also, Christian proposed in a previous mail to replace the G1 barrier
>> stubs on SPARC with simple runtime calls like on other platforms.
>> While I think that it is probably worthwhile thinking about such a
>> change, I don't know the exact history of these stubs and probably
>> some GC experts should decide if that's really a good idea. I'd be
>> happy to open an extra issue for following up on that path.
>>
>> But for the moments I've simply added a new initialization step
>> "g1_barrier_stubs_init()" between 'univers_init()' and
>> interpreter_init() which is empty on all platforms except SPARC where
>> it generates the corresponding stubs:
>>
>> http://cr.openjdk.java.net/~simonis/webrevs/2017/8166317.v3/
>>
>> I've built and smoke-tested the new change on Windows, MacOS,
>> Solaris/SPARC, AIX, Linux/x86_64/ppc64/ppc64le/s390. Unfortunately I
>> don't have access to ARM machines so I couldn't check arm,arm64 and
>> aarch64 although I don't expect any problems there (actually I've just
>> added an empty method there). But it would be great if somebody could
>> check that for any case.
>>
>> @Vladimir: I've also rebased the change for "8187091:
>> ReturnBlobToWrongHeapTest fails because of problems in
>> CodeHeap::contains_blob()":
>>
>> http://cr.openjdk.java.net/~simonis/webrevs/2017/8187091.v2/
>>
>> Because it changes the same files like 8166317 it should be applied
>> and pushed only after 8166317 was pushed.
>>
>> Thank you and best regards,
>> Volker
>>
>>> --
>>> Andrew Haley
>>> Java Platform Lead Engineer
>>> Red Hat UK Ltd. <https://www.redhat.com>
>>> EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671