Join GitHub today
GitHub is home to over 28 million developers working together to host and review code, manage projects, and build software together.Sign up
os/bluestore: tune deferred_batch_ops separately for hdd and ssd #14435
On HDD with NVMe WAL/DB and QD1, I'm seeing improvements even up to to 512 batched ops (though in reality the writes currently don't coalesce that well at the blk layer). I'd be tempted to bump the default HDD batched ops up to 128 (or higher) depending on the side effects.
They coalesce nicely for sequential IO but it will be a big batch of random IOs to throw at the disk for other workloads. We should verify that it is a win for random writes too. I suspect we'll want to have something that explicitly identifies sequential (coalesced) ios before turning the value up too high...