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

[Andrew Haley]

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.

> 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,
Andrew.