Java 64 bit consumes excessive native memory (c-heap) due to JIT Compilation

[Vitaly Davidovich]

Reserving a 64mb private heap sounds fine on 64bit, but it sounds like that
memory is being committed since RSS goes up?

Sent from my phone
On Aug 22, 2012 12:34 PM, "Andrew Haley" <aph at redhat.com> wrote:

> On 08/22/2012 05:26 PM, Ashish Saxena wrote:
> > I doubt if this is thread local memory area, for this disappears when
> > moving to interpreted mode(-Xint) or static compilation mode (-Xcomp).
> > Moreover, this occurs when JIT Compiler tries to do optimizations
> > related to inlining. On disabling the inling optimizations using
> > -XX:-Inline   the 64 MB blocks disappears.
>
> Point taken.  I would expect to see those 64M blocks on 64-bit systems,
> and I would expect to see about ten of them, but it's unconnected with
> JIT compilation.
>
> > Moreover, why would thread local area be so large ... 64 MB when
> > thread stack size is usually 1 MB. Any thoughts ?
>
> That's because address space is almost free on 64-bit systems: the C
> heap might as well allocate a block of address space to make malloc()
> extra fast.
>
> Andrew.
>
>
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