3 ms·
Is this one of those things that hypothetically could happen in the future or are there kernels that actually do this right now?
by dataflow 6y ago
Is this one of those things that hypothetically could happen in the future or are there kernels that actually do this right now?
- wiml 6y agoReordering disk io requests to minimize seek time and rotational latency has been a standard OS behavior since the 1970s, at least. Whether it's still effective in an SSD+io_uring world I don't know but I'm curious.
- astrange 6y agoIf you can issue multiple requests at once then they can go into the SSD controller's queues where it can reorder them, so it is beneficial. As usual with parallelism, it's hard to find if you look for it bottom-up, so running multiple processes is a better way to take advantage of it.
- doctor_eval 6y agoI learned about “elevator algorithms” in CS in the early 90s, well before Linux was a thing... I think it was common even then.