[Bitcoin-development] RPC and signals - processing priority

[grarpamp]

While happily processing these:
received block ...
SetBestChain: new best=...  height=...  work=...
ProcessBlock: ACCEPTED

bitcoind very often refuses to answer rpc queries such as getinfo/stop,
or signals such as kill/ctrl-c. It even registers:
 ThreadRPCServer method=getinfo/stop
in the debug log. But the action doesn't happen as expected.

Shouldn't it be checking and processing all user interrupts like
once per block and doing the chain in the background?

How do busy commerce servers deal with this poor rpc handling?

Is there a way to increase the priority of user scheduled tasks?
What's going on? Thanks.