Using non-volatile random access memory as volatile random access memory

A non-transitory computer readable storage medium having stored thereon program code executable by a computer system, the program code embodying a method comprising:

• detecting, by a computer system, that an amount of free space in a volatile random access memory (RAM) pool of the computer system has become low;
• in response to detecting that the amount of free space in the volatile RAM pool has become low, determining whether there is sufficient free space in a non-volatile random access memory (NVM) of the computer system to grow the volatile RAM pool by a chunk size of C memory pages;
• if there is insufficient free space in the NVM to grow the volatile RAM pool by the chunk size of C memory pages, freeing one or more memory pages in the volatile RAM pool using page swapping;
• and
• if there is sufficient free space in the NVM to grow the volatile RAM pool by the chunk size of C memory pages:
• creating a volatile RAM region in the NVM comprising C NVM memory pages;
• updating one or more internal data structures of a memory scheduler of the computer system to recognize the volatile RAM region in the NVM as being part of the volatile RAM pool;
• subsequently to the updating, detecting that an amount of free space in the NVM has become low;
• and
• in response to detecting that the amount of free space in the NVM has become low:
• selecting S NVM memory pages from the volatile RAM region in the NVM, wherein S is different from C;
• and
• for each of the selected S NVM memory pages:
• identifying a process of the computer system that is currently using the NVM memory page;
• and
• if there is sufficient free space in the volatile RAM pool, remapping contents of the NVM memory page from the volatile RAM region in the NVM to the volatile RAM pool.

A computer system comprising:

• a volatile random access memory (RAM) pool;
• a non-volatile random access memory (NVM) that allows for byte-addressable access to data in a manner similar to volatile RAM;
• a processor;
• and
• a non-transitory computer readable medium having stored thereon program code that, when executed, causes the processor to:
• detect that an amount of free space in the volatile RAM pool has become low;
• in response to detecting that the amount of free space in the volatile RAM pool has become low, determine whether there is sufficient free space in the NVM to grow the volatile RAM pool by a chunk size of C memory pages;
• if there is insufficient free space in the NVM to grow the volatile RAM pool by the chunk size of C memory pages, free one or more memory pages in the volatile RAM pool using page swapping;
• and
• if there is sufficient free space in the NVM to grow the volatile RAM pool by the chunk size of C memory pages:
• create a volatile RAM region in the NVM comprising C NVM memory pages;
• update one or more internal data structures of a memory scheduler of the computer system to recognize the volatile RAM region in the NVM as being part of the volatile RAM pool;
• subsequently to the updating, detect that an amount of free space in the NVM has become low;
• and
• in response to detecting that the amount of free space in the NVM has become low:
• select S NVM memory pages from the volatile RAM region in the NVM, wherein S is different from C;
• and
• for each of the selected S NVM memory pages:
• identify a process of the computer system that is currently using the NVM memory page;
• and
• if there is sufficient free space in the volatile RAM pool, remap contents of the NVM memory page from the volatile RAM region in the NVM to the volatile RAM pool.