RFR JDK-8059510 Compact symbol table layout inside shared archive

[Jiangli Zhou]

Hi Aleksey,

On 10/13/2014 11:46 AM, Aleksey Shipilev wrote:
> Hi Jiangli,
>
> On 13.10.2014 18:26, Jiangli Zhou wrote:
>> On 10/13/2014 03:18 AM, Aleksey Shipilev wrote:
>>> On 13.10.2014 03:32, David Holmes wrote:
>>>> On 11/10/2014 1:47 PM, Jiangli Zhou wrote:
>>>> Also is the benchmarking being done on dedicated systems?
>>> Also, specjvm98 is meaningless to estimate the classloading costs.
>>> Please try specjvm2008:startup.* tests?
>> The specjvm run was for Gerard's question about standard benchmarks.
> SPECjvm2008 is a standard benchmark. In fact, it is a benchmark that
> deprecates SPECjvm98.
>
>> These are not benchmarks specifically for classloading.
> There are benchmarks that try to estimate the startup costs.
> SPECjvm2008:startup.* tests are one of them.
>
>> However, I agree it's a good idea to run standard benchmarks to
>> confirm there is no overall performance degradation. From all the
>> benchmarks including classloading measurements, we have confirmed
>> that this specific change does not have negative impact on
>> classloading itself and the overall performance.
> Excellent. What are those benchmarks? May we see those? Because I have a
> counter-example in this thread that this change *does* negatively impact
> classloading.

The classloading measurements that I done used a test that loads 17436 
classes from the boot classpath with -Xshare:on. Please see my other 
email for detailed data on both x86 and ARMv7. The test is not publicly 
available. I can send it to you in a separate email.

BTW, could you please let me know who many sample you collected in your 
measurements, since I found the classloading speed can fluctuate even 
for the same binary and on a quiet machine.

Thanks,
Jiangli

>
> -Aleksey.
>