On Wed, Aug 10, 2016 at 08:14:45AM +0800, Yuyang Du wrote: > Hi Peter, > > I should have sent out my flat util hierarchy implementation long time ago, > actually code was there but not rebased. I finally have time to do this, > so here it is. There are also other proposals to solve migrated tasks' util > mobility problem, such as the ones from Dietmar and Vincent. > > The sched avgs computation optimization was initiated for the flat util thing, > so I send them out together. > > According to Morten and Ben's feedback, I removed 32-bit as a period's upper > bound limit. So, thanks a lot to them. >
To compare the effectiveness of the flat util hierarchy, a simple experiment was done: rt-app to generate a 50% duty-cycling workload (100us/200us), and in the meantime a script to set the CPU affinity of the task, alternating to taskset the task to run on CPU x and CPU y every 0.3 sec, so forcing the task to ping-pong migrate. By auto-group and ssh itself, the task under test is at the third level task group. So compare the top cfs_rq's util_avg (group_hierarchy.jpg) vs. the rq's util_avg (flat_hierarchy.jpg) Thanks, Yuyang
