US Patent 11630774 Preventing overwriting of shared memory line segments

Techniques are disclosed for preventing overwriting of shared line segments. The techniques include sending a data unit from a first processor to second processor using an augmented hardware cache coherency protocol, the augmented hardware cache coherency protocol being augmented to maintain dirty bits information during an exchange of the data unit within a cache coherency domain. A size of the data unit is a fraction of a size of any shared line of a shared memory, and writing the data unit to a segment of a shared line of a shared memory includes using another protocol, without overwriting another segment of the shared line. The writing is based at least in part on the dirty bits information, and the other protocol does not support hardware coherency and maintains the dirty bits information.