On Thu, Mar 02, 2023 at 09:54:59PM -0500, Martin K. Petersen wrote: > > For example, most cloud storage devices are doing read-ahead to try to > > anticipate read requests from the VM. This can interfere with the > > read-ahead being done by the guest kernel. So being able to tell > > cloud storage device whether a particular read request is stemming > > from a read-ahead or not. > > Indeed. In our experience the hints that work best are the ones which > convey to the storage device why the I/O is being performed. This may be a pretty far-out-there idea, but I think SSD BPF injection has potentially higher payoff than mere hints. The below paper does it in kernel, but imagine doing it on the device! https://dl.acm.org/doi/pdf/10.1145/3458336.3465290