On Fri, 30 Aug 2024 07:27:45 GMT, Stefan Karlsson <stef...@openjdk.org> wrote:
>> src/hotspot/share/gc/shared/gcForwarding.cpp line 37:
>>
>>> 35: size_t max_narrow_heap_size = right_n_bits(NumLowBitsNarrow - Shift);
>>> 36: if (UseCompactObjectHeaders && max_heap_size > max_narrow_heap_size *
>>> HeapWordSize) {
>>> 37: FLAG_SET_DEFAULT(UseCompactObjectHeaders, false);
>>
>> Maybe a log-info/warning would be nice.
>
> Yes. This silent setting of UseCompactObjectHeaders ended up hiding why we
> got CDS failures. I would also suggest that we change this to FLAG_SET_ERGO.
Seems we run all into the same thoughts :)
I added
Suggestion:
FLAG_SET_DEFAULT(UseCompactObjectHeaders, false);
warning("Compact object headers require a java heap size smaller than %zu
(given: %zu). "
"Disabling compact object headers.", max_narrow_heap_size *
HeapWordSize, max_heap_size);
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/20677#discussion_r1738127194
