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<p class="MsoNormal">Hello all,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">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.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Details:<o:p></o:p></p>
<p class="MsoNormal">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.<o:p></o:p></p>
<p class="MsoNormal">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.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The description of the feature can be found at <a href="https://bugs.openjdk.java.net/browse/JDK-8153327">
https://bugs.openjdk.java.net/browse/JDK-8153327</a><o:p></o:p></p>
<p class="MsoNormal">and the webrev is uploaded at <a href="http://cr.openjdk.java.net/~vdeshpande/8153327/webrev.00/">
http://cr.openjdk.java.net/~vdeshpande/8153327/webrev.00/</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">References:<o:p></o:p></p>
<p class="MsoNormal">[1] <a href="https://www.kernel.org/doc/Documentation/filesystems/dax.txt">
https://www.kernel.org/doc/Documentation/filesystems/dax.txt</a><o:p></o:p></p>
<p class="MsoNormal">[2] <a href="https://www.kernel.org/doc/Documentation/filesystems/ext4.txt">
https://www.kernel.org/doc/Documentation/filesystems/ext4.txt</a><o:p></o:p></p>
<p class="MsoNormal">[3] https://newsroom.intel.com/press-kits/introducing-intel-optane-technology-bringing-3d-xpoint-memory-to-storage-and-memory-products/<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Much appreciated!<o:p></o:p></p>
<p class="MsoNormal">Thanks you.<o:p></o:p></p>
<p class="MsoNormal">Kishor Kharbas<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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