Coherence-based cache-line Copy-on-Write

A method of performing a copy-on-write on a shared memory page is carried out by a device communicating with a processor via a coherence interconnect. The method includes: adding a page table entry so that a request to read a first cache line of the shared memory page includes a cache-line address of the shared memory page and a request to write to a second cache line of the shared memory page includes a cache-line address of a new memory page; in response to the request to write to the second cache line, storing new data of the second cache line in a second memory and associating the second cache-line address with the new data stored in the second memory; and in response to a request to read the second cache line, reading the new data of the second cache line from the second memory.