Hello, On Fri, Nov 30, 2018 at 04:13:07PM -0800, Daniel Jordan wrote: > On Fri, Nov 30, 2018 at 11:18:19AM -0800, Tejun Heo wrote: > > Hello, > > > > On Mon, Nov 05, 2018 at 11:55:45AM -0500, Daniel Jordan wrote: > > > Michal, you mentioned that ktask should be sensitive to CPU utilization[1]. > > > ktask threads now run at the lowest priority on the system to avoid disturbing > > > busy CPUs (more details in patches 4 and 5). Does this address your concern? > > > The plan to address your other comments is explained below. > > > > Have you tested what kind of impact this has on bandwidth of a system > > in addition to latency? The thing is while this would make a better > > use of a system which has idle capacity, it does so by doing more > > total work. It'd be really interesting to see how this affects > > bandwidth of a system too. > > I guess you mean something like comparing aggregate CPU time across threads to > the base single thread time for some job or set of jobs? Then no, I haven't > measured that, but I can for next time. Yeah, I'm primarily curious how expensive this is on an already loaded system, so sth like loading up the system with a workload which can saturate the system and comparing the bw impacts of serial and parallel page clearings at the same frequency. Thanks. -- tejun