Current heap layout of generational mark-sweep GC

[Jon Masamitsu]

Regarding "PrintMallocFree" it is broken in the sense that not
all malloc()/free() calls are wrapped inside the corresponding
AllocateHeap()/FreeHeap().  I've used it maybe once.   I don't
know what to say about why it's gone stale.

Neo Jia wrote:

> On 5/14/07, Jon Masamitsu <Jon.Masamitsu at sun.com> wrote:
>
>> Neo,
>>
>> If by "generational mark-sweep GC" you mean the UseSerialGC
>> or UseParNewGC,
>
>
> I mean the UseSerialGC.
>
>  yes the storage you listed are the major
>
>> pieces that we allocate in the CHeap.   There are many smaller
>> data structures that are allocated out of the CHeap.  For example,
>> performance counters are CHeap allocated.  Or just the storage
>> for various subclasses of Generation that the GC uses.
>>
>> I believe the largest piece of the CHeap that the compilers
>> use is the CodeCache and it is allocated before the Java
>> heap is allocated.
>
>
> The current "PrintMallocFree" seems broken already. Do you still use
> this to check the
> CHeap usage?
>
> Thanks,
> Neo
>
>>
>> Jon
>>
>> Neo Jia wrote:
>>
>> > On 5/14/07, Jon Masamitsu <Jon.Masamitsu at sun.com> wrote:
>> >
>> >> Neo,
>> >>
>> >> Are you asking specifically about CHeap usage by the
>> >> garbage collector (i.e., you're not interested in the
>> >> compiler's use CHeap space)?
>> >
>> >
>> > Jon,
>> >
>> > Although my question is about the CHeap usage by GC, I am also 
>> interested
>> > in knowing the CHeap space usage of compiler.
>> >
>> > Thanks,
>> > Neo
>> >
>> >>
>> >> Jon
>> >>
>> >>
>> >> Neo Jia wrote:
>> >>
>> >> > hi,
>> >> >
>> >> > I am wondering that for the generational mark-sweep GC, if the 
>> block
>> >> > offset shared array is the last allocated object on the CHeap.
>> >> >
>> >> > The following is my understanding of the current heap layout:
>> >> >
>> >> > 1. The nursery space is on the lowest address
>> >> > 2. The mature space is following the nursery address.
>> >> > 3. The permanent space is following the nursery address at a higher
>> >> > address.
>> >> > 4. The card table is allocated from the end of the permanent space,
>> >> > the regions inside it will be mapped to these previous three spaces
>> >> > sequentially, from lower address to higher address.
>> >> > 5. The block offset shared array used by the mature space will be
>> >> > allocated at the end of the card table area, which is used by 
>> mature
>> >> > space. And the virtual space size of this area will be set 
>> according
>> >> > to the mature space and word bits.
>> >> >
>> >> > So, is there any space allocated following?
>> >> >
>> >> > Thanks,
>> >> > Neo
>> >>
>> >>
>> >
>> >
>>
>
>