On Tue, 2004-10-12 at 01:50, Simon Derr wrote: > > One of the cool thing about using sched_domains as your partitioning > > element is that in reality, tasks run on *CPUs*, not *domains*. So if > > you have threads 'a1' & 'a2' running on CPUs 0 & 1 (small job 'a') and > > threads 'b1' & 'b2' running on CPUs 2 & 3 (small job 'b'), you can > > suspend threads a1, a2, b1 & b2 and remove the domains they were running > > in to allow job A (big job with threads A1, A2, A3, & A4) to run on the > > larger 4 CPU domain. When you then suspend A1-A4 again to allow the > > smaller jobs to proceed, you can pretty trivially create the 2 CPU > > domains underneath the 4 CPU domain and resume the jobs. Those jobs (a > > & b) have been suspended on the CPUs they were originally running on, > > and thus will resume on the same CPUs without any extra effort. They > > will simply run on those CPUs, and at load balance time, the domains > > attached to those CPUs will be consulted to determine where the tasks > > can be relocated to if there is a heavy load. The domains will tell the > > scheduler that the tasks cannot be relocated outside the 2 CPUs in each > > respective domain. Viola! (sorta ;) > Voilà ;-)
hehe... My French spelling obviously isn't quite up to par. ;) > I agree that this looks really smooth from a scheduler point of view. > > From a user point of view, remains the issue of suspending the tasks: > -find which tasks to suspend : how do you know that job 'a' consists > exactly of 'a1' and 'a2' > -suspend them (btw, how do you achieve this ? kill -STOP ?) > > > I've been away from my mail and still trying to catch up, nevermind if the > above does not makes sense to you. > > Simon. Paul didn't go into specifics about how to suspend the job, so neither did I. Sending SIGSTOP & SIGCONT should work, as you mention... Those are implementation details which really aren't *that* important to the discussion. We're still trying to figure out the overall framework and API to work with, so which method of suspending a thread we'll eventually use can be tackled down the road. :) -Matt ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ ckrm-tech mailing list https://lists.sourceforge.net/lists/listinfo/ckrm-tech
