[aarch64-port-dev ] AARCH64: 8064611: Changes to HotSpot shared code

[Vladimir Kozlov]

On 11/14/14 9:17 AM, Andrew Haley wrote:
> On 11/14/2014 05:06 PM, Vladimir Kozlov wrote:
>> Thank you Edward and Andrew for explanation.
>>
>> So defaults are next:
>>
>> aarch64(C1) ReservedCodeCacheSize = 32*M
>> aarch64(C2) ReservedCodeCacheSize = 48*M
>>
>> I understand that *5 will exceed 128MB limit. My concern here is
>> that our experience shows that TieredCompilation will eat 200MB very
>> easy. So with 128MB you may hit performance issues during long runs
>> (C1 does not stop compiling) because there will be not enough space
>> for code and we will start evicting old compiled code or stop
>> compiling.
>
> Perhaps there is something I am not understanding: isn't evicting old
> compiled code really a good thing to do, thus avoiding many
> indirections?  I suppose it's a matter of whether any application has
> a working set size of more than 128Mb for the code cache, although I
> can see that fragmentation might be an issue.
>
> Anyway, as I indicated, I'm quite willing to revisit this at a later
> date, if that's okay with you.

Yes, I am perfectly fine with that.

>
>> Okay, how about a constant (#define CODE_CACHE_SIZE_LIMIT
>> NOT_AARCH64(2*G) ARCH64_ONLY(138*M)) in this place so you can use it
>> in these 2 checks?
>
> Will do.

Thanks,
Vladimir

>
> Thanks,
> Andrew.
>