Abstract: A journal-based process to achieve atomicity in a device driver write operation includes committing a transaction associated with the operation to a journal that include a status indicating the target block is corrupted. Subsequent to committing the transaction, the data is written to the target block. If the write operation is successfully committed, the transaction can be deleted from the journal. If a system crash occurs (e.g., power failure) before the write operation is successfully committed, the transaction remains in the journal and can be used to update block metadata associated with the target block when the system reboots to indicate that it is corrupted; e.g., the target block is a torn write.

Abstract: A journal-based process to achieve atomicity in a device driver write operation includes committing a transaction associated with the operation to a journal that include a status indicating the target block is corrupted. Subsequent to committing the transaction, the data is written to the target block. If the write operation is successfully committed, the transaction can be deleted from the journal. If a system crash occurs (e.g., power failure) before the write operation is successfully committed, the transaction remains in the journal and can be used to update block metadata associated with the target block when the system reboots to indicate that it is corrupted; e.g., the target block is a torn write.

Abstract: Techniques for checking the compressibility of a memory page that is allocated to a virtual machine (VM) running on a host system are provided. In one embodiment, the host system can determine a compression ratio for the memory page by compressing the memory page using a first compression algorithm. The host system can then compare the compression ratio to a threshold. If the compression ratio does not exceed the threshold, the host system can predict that the memory page is compressible by a second compression algorithm that is distinct from the first compression algorithm. On average, the second compression algorithm can be slower, but achieve a lower compression ratio, than the first compression algorithm.

Abstract: Techniques for building a list of swap candidate pages for host swapping are provided. In one embodiment, a host system can determine a swap target virtual machine (VM) and a target number of swap candidate pages. The host system can further select a memory page from a memory space of the swap target VM and can check whether the memory page is sharable or compressible. If the memory page is sharable or compressible, the host system can add the memory page to the list of swap candidate pages.

Abstract: Techniques for building a list of swap candidate pages for host swapping are provided. In one embodiment, a host system can determine a swap target virtual machine (VM) and a target number of swap candidate pages. The host system can further select a memory page from a memory space of the swap target VM and can check whether the memory page is sharable or compressible. If the memory page is sharable or compressible, the host system can add the memory page to the list of swap candidate pages.

Abstract: Techniques for checking the compressibility of a memory page that is allocated to a virtual machine (VM) running on a host system are provided. In one embodiment, the host system can determine a compression ratio for the memory page by compressing the memory page using a first compression algorithm. The host system can then compare the compression ratio to a threshold. If the compression ratio does not exceed the threshold, the host system can predict that the memory page is compressible by a second compression algorithm that is distinct from the first compression algorithm. On average, the second compression algorithm can be slower, but achieve a lower compression ratio, than the first compression algorithm.