On Thu, Jun 22, 2023 at 03:55:52AM +0100, Matthew Wilcox wrote: > Latency is important for reads, but why is it important for writes? > There's such a thing as a dependent read, but writes are usually buffered > and we can wait as long as we like for a write to complete. That was exactly my reasoning on why I did always defer the write completions in the initial iomap direct I/O code, and until now no one has complained. I could see why people care either about synchronous writes, or polled io_uring writes, for which we might be able to do the work in the completion thread context, but for aio writes this feels a bit odd.