Supporting allocation of Java object heap on NV-DIMMS

Kharbas, Kishor kishor.kharbas at
Sat Apr 2 01:13:48 UTC 2016

Hello all,

I would like to propose adding a capability in the JVM to allocate object heap on new kinds of heterogeneous memories which are exposed through a file system. This could be achieved by adding a command line option to specify a path in the filesystem which would be used for mmap() system call.

Linux kernel 4.0 onwards supports DAX mode[1] in Ext4 file system [2] which is designed to support new heterogeneous memory devices such as Intel's 3D XPoint memory [3]. DAX mode removes the need for page cache and provides a direct mapping of process virtual space to storage space.
We would like to add a command line option called "FSDirForHeap" which will - 1) Enable using a file system as backing store for Java object heap 2) Use the provided path to create a temporary file for mmap() system call.

The description of the feature can be found at
and the webrev is uploaded at


Much appreciated!
Thanks you.
Kishor Kharbas

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