On Mon, Nov 10, 2008 at 10:48:54AM +0800, Li Zefan wrote: > Hi, Vivek > > Thanks for your work. :) > > A question below. > > > +For example, assume there are two cgroups A and B with weights 1024 and 2048 > > +in the system. Tasks in two cgroups A and B are doing IO to two disks sda and > > +sdb in the system. A user has enabled IO control on both sda and sdb. Now on > > +both sda and sdb, tasks in cgroup B will get to use 2/3 of disk BW and > > +tasks in cgroup A will get to use 1/3 of disk bandwidth, only in case of > > +contention. If tasks in any of the groups stop doing IO to a particular disk, > > +task in other group will get to use full disk BW for that duration. > > + > > So in this example, I can't assign 1/3 of sda's disk BW while 2/3 of sdb's > disk BW to A. Am I right? Hi, Yes you are right. Currently policies are global and not per disk. So in above example, cgroup A will get 1/3 of disk BW both on sda and sdb. And one can not configure in such a manner so that A gets 1/3 of BW on sda and 2/3 of BW on sdb. I think assigning cgroup weights per disk should be doable but personally I think it makes configuration complex and I am not sure if it really a very useful feature. Thanks Vivek _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
