Did you know...? LWN.net is a subscriber-supported publication; we rely on subscribers to keep the entire operation going. Please help out by buying a subscription and keeping LWN on the net. The restartable sequences feature, which was added to the 4.18 kernel in 2018, exists to enable better performance in certain types of threaded applications. While there are users for restartable sequences, they tend to be relatively specialized code; this is not a tool that most application developers re...