RFR: 8281455: Change JVM options with small ranges from 64 to 32 bits, for gc_globals.hpp [v2]

[Afshin Zafari]

On Wed, 7 Jun 2023 09:30:46 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

>> Afshin Zafari has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   some more intx to int conversions.
>
> src/hotspot/share/gc/parallel/psAdaptiveSizePolicy.cpp line 352:
> 
>> 350:           "PSAdaptiveSizePolicy::compute_eden_space_size: gc time limit"
>> 351:           " gc_cost: %f "
>> 352:           " GCTimeLimit: " UINT32_FORMAT,
> 
> We use `%u` as format specifiers for uint.

`%u` is used.

> src/hotspot/share/gc/shared/gcOverheadChecker.cpp line 94:
> 
>> 92:   if (UseGCOverheadLimit) {
>> 93:     if (gc_overhead_limit_exceeded()) {
>> 94:       log_trace(gc, ergo)("GC is exceeding overhead limit of %d%%", GCTimeLimit);
> 
> Not sure why this place uses `%d` as format specifier compared to the `UINT32_FORMAT` the previous places did. Use `%u` ;)

`%u` is used.

> src/hotspot/share/gc/shared/gc_globals.hpp line 169:
> 
>> 167:           "(effective only when using concurrent collectors)")              \
>> 168:                                                                             \
>> 169:   product(uint, GCLockerEdenExpansionPercent, 5,                           \
> 
> The `` needs to be aligned back.

Fixed.

> src/hotspot/share/utilities/globalDefinitions.hpp line 442:
> 
>> 440: 
>> 441: typedef unsigned int uint;   NEEDS_CLEANUP
>> 442: const uint  max_uint  = (uint)-1;
> 
> The change should use the existing `UINT_MAX` instead of adding a new constant. Instead of a cast of `-1`, one should also use `~0` to get all-ones.

`UINT_MAX` is used. New definition of max_uint is removed.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14259#discussion_r1221420802
PR Review Comment: https://git.openjdk.org/jdk/pull/14259#discussion_r1221421539
PR Review Comment: https://git.openjdk.org/jdk/pull/14259#discussion_r1221421846
PR Review Comment: https://git.openjdk.org/jdk/pull/14259#discussion_r1221423013