RFR: 8306843: JVMTI tag map extremely slow after JDK-8292741 [v2]

[Coleen Phillimore]

On Mon, 8 May 2023 04:20:21 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Remove return variable from remove lambda, fix formatting.
>
> src/hotspot/share/classfile/stringTable.cpp line 638:
> 
>> 636:  public:
>> 637:   size_t _errors;
>> 638:   VerifyCompStrings() : _table(unsigned(_items_count / 8) + 1, 0 /* do not resize */), _errors(0) {}
> 
> Shouldn't this use a regular ResourceHashtable instead?

It didn't trivially compile and I didn't want to change the code for this unrelated table to fix this bug.  I will file a new RFE to fix this.

> src/hotspot/share/utilities/resizeableResourceHash.hpp line 91:
> 
>> 89:   // Calculate next "good" hashtable size based on requested count
>> 90:   int calculate_resize(bool use_large_table_sizes) const {
>> 91:     const int resize_factor = 2;     // by how much we will resize using current number of entries
> 
> Does this function depend on the template parameters? If not, I think it can be made a static function -- you may need to pass `BASE::number_of_entries()` in as a parameter.

I don't see the reason to do that.  It makes the caller noisier.

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PR Review Comment: https://git.openjdk.org/jdk/pull/13818#discussion_r1187480076
PR Review Comment: https://git.openjdk.org/jdk/pull/13818#discussion_r1187483036