On Thu, Jul 01, 2004 at 14:47:01 -0400, Benoit Lefebvre wrote: > There are many type of lock and each of them have their own utility. If you > can sleep, semaphore is probably what you'll use. Example: > > static DECLARE_MUTEX(m); > > down(&m); > /* accessing your global structure */ > up(&m); It is correct, but not as a reply to the question below. The question below is specificaly targeted at task_structs and you need to aquite the existing lock. It follows from the nature of task_struct, that the lock is a spin_lock, not a semaphore. > On July 1, 2004 02:29 pm, Greg Nate wrote: > > Regarding acquiring a lock: I realize this may be a stupid question, > > but how does one go about doing this? Can you provide a short code > > example? > > > > Thanks > > > > -----Original Message----- > > From: kernelnewbies-bounce@nl.linux.org > > [mailto:kernelnewbies-bounce@nl.linux.org]On Behalf Of Dhiman, Gaurav > > Sent: Thursday, July 01, 2004 9:27 AM > > To: Anupam Kapoor; manish regmi > > Cc: so_usp@yahoo.com.br; kernelnewbies@nl.linux.org > > Subject: RE: List of Processes > > > > > > > > We need to acquire lock before accessing any common data structure of > > kernel. As the "task_struct" list is the common data structure of kernel > > which is accessed from different places in kernel. > > We need to acquire the lock for this task list before accessing it, so > > that when we are accessing the list no other process context or kernel > > thread should be able to access it. ------------------------------------------------------------------------------- Jan 'Bulb' Hudec <bulb@ucw.cz>
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