I did some searching & am a bit shocked: I couldn't find any way to adjust io priority other than by altering the entire processes io level. I would have though

I did some searching & am a bit shocked: I couldn't find any way to adjust io priority other than by altering the entire processes io level. I would have though this would be a semi-commonly used routine to make high/regulae/low priority QoS for io, but indeed, per your claims, I can't seem to find anything. Hypothetically one could maybe spawn a bunch of child processes and give them each their own io priority? Maybe io priority is sticky, and one can change io priority just before doing io work, and the io priority for that work would stay when one changes the io priority before the next operation? I feel like we have a bunch of possible things we could to better qos with what controls we have. Therw are also a variety of madvise hints we can provide, telling the kernel what we will need, what to drop, what we won't need, what will be random access (not benefit from lookahead) Vs sequential. These already are some pretty useful knobs. Which I'd guess are quite broadly underused.