RFR(XS): 8193521: glibc wastes memory with default configuration

[Severin Gehwolf]

On Thu, 2017-12-14 at 19:06 +0000, Andrew Haley wrote:
> On 14/12/17 18:51, Doerr, Martin wrote:
> > And I also assume that most JVM users don't know that the JVM has
> > own arena implementation etc. which makes glibc arenas under the
> > hood useless for these kind of allocations. 
> > So I think it would be nice if we could help these people.
> 
> So, here's a radical thought: why are we using malloc() at all?
> Shouldn't we be calling mmap() and then basing our arena in that?

Failing that it would make sense to limit the max arenas based on the
cpu share's a container gets (OSContainer::active_processor_count()).
I.e. it could be part of JEP 8182070, Container aware Java. Thoughts?

Thanks,
Severin