On Mon, 15 Feb 2021 18:21:53 GMT, Lutz Schmidt <[email protected]> wrote:
>> This is a request for help. Could someone with SA knowledge please check if
>> my assumption is correct?
>>
>> In hotspot code, the field Method::_compiled_invocation_count is annotated
>> with a comment that it is used by SA. The field is also exposed via
>> vmStructs.cpp to enable such use. I have scanned SA code in OpenJDK11 and
>> OpenJDK head but found no evidence that this particular field is accessed.
>> Is this finding/assumption correct?
>>
>> If so, I could just stop exposing the field, making my life easier. Thanks!
>
> Looks like I have completely messed up my pull request. Please disregard for
> now. I'm trying to find a way how to clean up. Maybe I'll just start over.
OK, my pull request is back in a reviewable state. Here is what changed:
1) Honouring review comments from @TobiHartmann and @veresov
Trusting my own code research, I removed _compiled_invocation_count from
vmStructs.cpp. Builds are ok and all tests we run in-house (including the jtreg
suite) did not show any issue. The updated pull request has
_compiled_invocation_count widened to 64-bit and all those *64 suffixes are
removed.
2) Dealing with counter updates in {v|i}table stubs
While waiting for a response from SA experts, I took the time and had a closer
look at the last remaining 32-bit counter (_nof_megamorphic_calls). It turned
out the required changes to code generation were trivial. So I took the
opportunity and made it a 64-bit counter. Call stats look even nicer now!
In summary: All global invocation counters are 64-bit now. From those counters
that register method-individual calls, only _compiled_invocation_count and
_nof_megamorphic_calls were widened to 64-bit. The three remaining
method-individual counters (invocation_count, interpreter_invocation_count. and
backedge_count) remain untouched.
I appreciate your feedback!
Here is how stats look like now:
Invocations summary for 28214 methods:
41055191904 (100%) total
4818528940 (11.7%) |- interpreted
36236662964 (88.3%) |- compiled
9065026571 (22.1%) |- special methods (interpreted and compiled)
607128840 ( 1.5%) |- synchronized
2107652419 ( 5.1%) |- final
6347934023 (15.5%) |- static
1122857 ( 0.0%) |- native
1188432 ( 0.0%) |- accessor
Calls from compiled code:
27011733837 (100%) total non-inlined
14500960686 (53.7%) |- virtual calls
124325246564 ( 857%) | |- inlined
0 ( 0%) | |- optimized
8890453008 ( 61%) | |- monomorphic
5610507678 ( 39%) | |- megamorphic
4529160753 (16.8%) |- interface calls
8905052200 ( 197%) | |- inlined
0 ( 0%) | |- optimized
4529160753 ( 100%) | |- monomorphic
0 ( 0%) | |- megamorphic
7981612398 (29.5%) |- static/special calls
73886243527 ( 926%) | |- inlined
-------------
PR: https://git.openjdk.java.net/jdk/pull/2511
