The disclosure provides an approach for testing if a cache line of a cache has been flushed to non-volatile memory (NVM). The approach generally includes reading, by a central processing unit (CPU), data from the NVM. The approach further includes storing, by the CPU, a copy of the data in the cache as a cache line. The approach further includes modifying, by the CPU, at least a portion of the copy of the data in the cache. The approach further includes requesting, by the CPU, the cache line be flushed to the NVM. The approach further includes performing, by the CPU, one or more instructions in parallel to the cache line being flushed to the NVM. The approach further includes requesting, by the CPU, a state of the cache line and determining if the cache line has been persisted in the NVM based on the state of the cache line.