Hi,
struct pid is a drop in replacement for a pid_t (except for the need for reference counting. Found this here http://lwn.net/Articles/257054/ On Tue, Jul 20, 2010 at 8:26 AM, Aiolia Lea <[email protected]> wrote: > Hi, All > > From linux kernel (2.6.30.4), I found two data structures, as follow: > > typedef __kernel_pid_t pid_t; > > struct pid > { > atomic_t count; > unsigned int level; > /* lists of tasks that use this pid */ > struct hlist_head tasks[PIDTYPE_MAX]; > struct rcu_head rcu; > struct upid numbers[1]; > }; > > According to my understanding, the pid_t is the frequent item we know, such > as in getpid() function, ps command and also. > > Then, what's the pid structure used for? and what's the relationship > between pid structure and pid_t? > > Why the kernel required to involved pid this structure? > > Hope you could give me some explanation or some links. > > Thank you very much~ > -- > Best Regards! > Aiolia Lea > -- Tushar Dadlani Manipal Institute of Technology +919986292434
