Hi... On Fri, Jul 18, 2008 at 10:43 AM, Xiaolan Zhang <zhang.xiaolan@xxxxxxx> wrote: > Hi, > I just wonder how 2.6 linux kernel schedule realtime jobs on a SMP > environment. Will try to answer based purely on my guess... >If two RT jobs are started on the same CPU and a low priority > job is started on another CPU, will linux move the second RT job to the > other CPU to preempt the low priority job? well, depends on the affinity setting. But assuming none of them are being "held" on certain core/processor, then yes...at the first moment preemption happen, one of the RT job will move to the other core and preempt that low priority job. However, load balancing between core is not something that happen very frequently. And scheduler should avoid cache invalidation due to job relocation as many as possible. So, to conclude, yes in the end RT job should preempt that low prio job..but I am not sure how fast it would happen. regards, Mulyadi. -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
