RT doesn't necessarily improve latency, it gives it a fixed upper bound for some operations. But the work needed to allow RT can definitely improve latency in

RT doesn't necessarily improve latency, it gives it a fixed upper bound for some operations. But the work needed to allow RT can definitely improve latency in the general case -- the example of avoiding synchronous printk() calls is a case in point. It should improve latency under load even when RT isn't even enabled. I think I'm right in asserting that a fully-upstreamed RT kernel won't actually do anything different from a normal one unless you're actually running RT processes on it. The reason it's taken so long to upstream has been the trade-offs that have been needed to enable RT, and (per the article) there aren't many of those left.