Can io scheduling priority be set on a filehandle basis?

Can open filehandles in linux have an io scheduling priority set on them? ionice allows you to set io priority for processes as a whole. Is it possible for a process to have, for example, idle priority on one filehandle but normal priority on another? Or, in order to implement something like this, would I need to be changing the processes' io scheduling prio开发者_开发知识库rity as reads are made from each filehandle?

I don't think there is, directly.

The Unix V6 kernel (c. 1978) would set the wakeup priority to different values based on the characteristics of some device types, based on the length of delay. If that functionality has carried over to Linux, then maybe that could be exploited for your purposes.

Otherwise, you'd have to modify the kernel for your purposes. Perhaps extend ioctl() to set a new field with scheduling bias per file.