On Thu, 2007-08-23 at 14:13 +0200, Ingo Molnar wrote: > * Ingo Molnar <[EMAIL PROTECTED]> wrote: > > > [...] So how about the patch below instead? > > the right patch attached. > > --------------------------------> > Subject: sched: fix broken SMT/MC optimizations > From: "Siddha, Suresh B" <[EMAIL PROTECTED]> > > On a four package system with HT - HT load balancing optimizations were > broken. For example, if two tasks end up running on two logical threads > of one of the packages, scheduler is not able to pull one of the tasks > to a completely idle package. > > In this scenario, for nice-0 tasks, imbalance calculated by scheduler > will be 512 and find_busiest_queue() will return 0 (as each cpu's load > is 1024 > imbalance and has only one task running).
Is there an upper bound on the number of tasks that can migrate during a new idle balance? The reason that I'm asking is because I've been seeing some large latency in the new idle path into load_balance().. I'm not sure if lots of tasks are getting migrated or if it's just the iteration over tasks in the rb-tree .. Daniel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
