can someone please help me puzzle this out? 1. we know that "ps auxwf" will list out all the processes (including kernel threads) and their parent-child relationship. so each of these have a "current", ie, the global task-struct ptr value called "current", enabling them to be schedulable. 2. lsmod will list all the modules loaded. I printk() the "current", and each running module have its own task struct ptr value. But ps cannot see any of them. But I supposed they should be on the schedulable list of task-struct right? Or may be not? (btw...the module are just simple module, not using kthread_run() or any other APIs) not sure....someone has to go through fs/proc/*.c to see how /proc/[pid] are printed. ie, how are all the PIDs enumerated? are the kernel modules skipped? On Mon, Oct 6, 2008 at 10:48 PM, Mulyadi Santosa <mulyadi.santosa@xxxxxxxxx> wrote: > Hi... > > On Mon, Oct 6, 2008 at 7:51 PM, Lal <learner.kernel@xxxxxxxxx> wrote: >> On Mon, Oct 6, 2008 at 12:03 PM, Mitul Modi <mituld.modi@xxxxxxxxx> wrote: >>> hi Lal, >>> >>> thanks for the analysis and clearing the doubt. so, parent process returns >>> while child is added in to runqueue. right? >>> >> >> Depends. For example if CLONE_VM is not set, then kernel runs child >> process first in anticipation of an exec to avoid COW overhead. >> If CLONE_VM is set then kernel puts the child process at the end of >> runqueue. The parent process continues through ret_from_intr where >> kernel may again decide to schedule it out and run another process >> (may be child process or some other). > > Even though it's not using CLONE_VM, the tendency is to prefer running > child first. IMO it has relationship with the way most programmer > expect. Parent forks, child does something, parent waits 'til child > exits. By letting child runs first, you save one context switch.... > since if you do the otherwise, parent runs first just to find itself > go into waiting state. > > 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 > > -- Regards, Peter Teoh -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
