Not a fan of JSON per se for this type of messaging, but I don't think binary parser+validator combinations are that much faster. Plus, this forces C(++) developers to actually validate the data they're exchanging rather than casting raw structs from data buffers, which solves a huge vulnerability. Then again, the lack of 64 bit integers makes the protocol design comically unsuited.
I don't think the serialization/deserialisation overhead matters much when also taking into account the bus connection overhead. I would've preferred a better data exchange format but out of all problems I have with Linux IPC, the performance of JSON is the least of my worries.
I don't think the serialization/deserialisation overhead matters much when also taking into account the bus connection overhead. I would've preferred a better data exchange format but out of all problems I have with Linux IPC, the performance of JSON is the least of my worries.