Cooperative memory resource management via application-level balloon

A method for managing memory in a host having virtualization software that supports execution of a virtual machine (VM), having a guest operating system that manages allocation of guest physical memory, a balloon driver installed in the guest operating system, and a Java Virtual Machine (JVM) executing as an application on top of the guest operating system and having a heap memory allocated from the guest physical memory, the method comprising:

• at the balloon driver, receiving a request from the virtualization software for memory pages and communicating a target number of memory pages to a Java balloon agent;
• allocating, by the Java balloon agent, a Java balloon object in the heap memory of the JVM, the Java balloon agent executing as a Java thread in the JVM, the Java balloon object being allocated a number of memory pages equal to the target number of memory pages;
• obtaining, by the Java balloon agent, a virtual address of the Java object;
• identifying a physical page number corresponding to the virtual address;
• sending the physical page number to the virtualization software;
• and
• reclaiming a machine physical memory page associated with the physical page number by the virtualization software.

A system for managing memory in a host that supports execution of virtual machines (VMs), the system comprising:

• one or more VMs, at least one of the VMs including,
• a guest operating system that manages allocation of guest physical memory;
• a balloon driver installed in the guest operating system that receives a request from the virtualization software for memory pages and communicates a target number of memory pages to a Java balloon agent;
• a Java virtual machine (JVM) executing as an application on top of the guest operating system and having a heap memory allocated from the guest physical memory, and
• a Java balloon agent executing as a Java thread in the JVM, wherein the Java balloon agent receives a target number of memory pages from the balloon driver and allocates a Java balloon object in the heap memory of the JVM, the Java balloon object being allocated a number of memory pages equal to the target number of memory pages, the Java balloon agent loading the Java balloon object with a first value;
• and
• virtualization software to reclaim machine physical memory pages associated with the Java ballon object when the machine physical memory pages have the first value.

A non-transitory computer readable storage medium comprising instructions that, when executed, cause a machine to at least:

• manage memory in a host having virtualization software that supports execution of a virtual machine (VM) having guest operating system that manages allocation of guest physical memory, a balloon driver installed in the guest operating system, a Java virtual machine (JVM) executing as an application on top of the guest operating system and having a heap memory allocated from the guest physical memory, and a Java balloon agent to execute as a Java thread in the JVM;
• receive at the balloon driver a request from the virtualization software for memory pages and communicate a target number of memory pages to the Java balloon agent;
• allocate a Java balloon object in the heap memory of the JVM by the Java balloon agent, the Java balloon object being allocated a number of memory pages equal to a target number of memory pages;
• load a first value into each of the memory pages of the Java balloon object, the loading being performed by the Java balloon agent;
• detect by the virtualization software machine physical memory pages having the first value;
• and
• reclaim the detected machine physical memory pages by the virtualization software.