Code and Design Feedback request: 7114376: tune system dictionary size

[Dean Long]

It is probably out of the scope of this CR, but is it possible that the 
internal data structure might one day change from monolithic hash table 
to something more hierarchical?  For example having a separate data 
structure per package or per classloader.  I was reading online about 
something called a HAT-trie that deals with shared prefixes and was 
designed with cache locality in mind.

dl

On 1/21/2012 11:04 AM, Karen Kinnear wrote:
> David,
>
> Thank you for asking, my mistake. Here is an accessible webrev.
>
> Webrev: http://cr.openjdk.java.net/~acorn/7114376/webrev/
>
> An alternative possibility for supplying a single flag might be: -XX:LoadedClasses=#
>
> This could be an anticipated count of expected total classes, which we could use
> internally to set the initial SystemDictionary size. This might outlast any internal changes
> in data structures.
>
> Tests run:
> vmsqe: nsk.quick.testlist: solaris-sparc, fastdbg - this includes sa testing
> jck: vm,lang,api: solaris-sparc, fastdbg
> JPRT - this includes CDS testing
> performance runs in progress, including frequency of checking need to resize
>
> thanks,
> Karen
>
> On Jan 21, 2012, at 12:04 PM, David Schlosnagle wrote:
>
>> On Fri, Jan 20, 2012 at 6:06 PM, Karen Kinnear<karen.kinnear at oracle.com>  wrote:
>>> Please review initial proposal for: 7114376: tune system dictionary size
>>>
>>> http://oklahoma.us.oracle.com/~kmkinnea/webrev/sdresize/webrev/
>> Karen,
>>
>> Is there a URL where this webrev is accessible outside of Oracle?
>>
>> Thanks,
>> Dave