Hi Vivek, On 2017/3/4 3:53, Vivek Goyal wrote: > On Fri, Mar 03, 2017 at 09:20:44PM +0800, Hou Tao wrote: > > [..] >>> Frankly, vdisktime is in fixed-point precision shifted by >>> CFQ_SERVICE_SHIFT so using CFQ_IDLE_DELAY does not make much sense in any >>> case and just adding 1 to maximum vdisktime should be fine in all the >>> cases. But that would require more testing whether I did not miss anything >>> subtle. > > I think even 1 will work. But in the beginning IIRC I took the idea > from cpu scheduler. Adding a value bigger than 1 will allow you to add > some other group later before this group. (If you want to give that group > higher priority). I still don't understand why using a value bigger than 1 will allow a later added group to have a vdisktime less than the firstly added group. Could you explain it in more detail ? Regards, Tao > Thanks > Vivek > > . >
