On Friday 02 January 2009 09:22:30 Shyam Burkule wrote: > Thanks for your replay. > > On Fri, Jan 2, 2009 at 2:23 AM, Henrik Austad <henrik@xxxxxxxxx> wrote: > > On Tuesday 30 December 2008 23:25:39 Shyam Burkule wrote: > > > Hi All, > > > > Hi! > > > > > Linux kernel make use list_head to link process descriptor. I am > > > reading scheduler part of Linux kernel. There is structure *runqueue* > > > > that > > > > > contains list of all runnable process. The *runqueue* has pointer to > > > *prio_array_t* structre that have field *queue*(array of struct > > > prio_array_t) which list process according to priority. The scheduler > > > > gets > > > > > head_list from this queue. > > > > First, which version of the kernel are you working with? > > I am working with kernel version 2.6.27.6. ah, ok, see below :-) > > From what you ask, it > > sounds like you are working with the O(1) scheduler setup. > > > > as Peter said, there's a individual instance of the runqueue, > > (kernel/sched.c > > struct rq). In this rq, you will find a cfs_rq struct (the runqueue for > > normal tasks) as well as a rt_rq struct. In these runqueues are the tasks > > runnable on a given CPU. > > > > The only place you will find prio_array, will be in the rt_rq runqueue, > > which > > has been renamed to rt_prio_array (as normal tasks do not use prio-array > > but > > red-black trees nowadays). > > But in UTLK I read that prio_array_t is used for both real-time and normal > processes. Ah, ok. I get it. Your problem is that UTLK is a bit outdaten on the scheduling part. UTLK covers 2.6.10 (as stated in the preface I think), and CFS was introduced (together with a lot of other new features) in the scheduler in 2.6.23. I have made an attempt to explain the difference, and how CFS works in my specialization project (http://folk.ntnu.no/henrikau/sched/rt_sched_pro.pdf section 2.3) Hopefully this can clearify a few things. The rest of the container_of was answered brilliantly by Alexander, so I'll snip that part off. -- -> henrik -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
