Causes for process going into D state

Hi

What are the causes for process going in to D state. (which is
interruptible).

One reason i got is, due to 'deadlock' the process may go in to dead
lock.

in my program i am using down(struct semaphore *) function which
places process to uninterruptible state. so I am seeing Process in D
state.

i am trying to copy kernel souce code but for 4 threads , after 1.1GB
all are going to D state.

is there any other causes for this?.

Thanks & Regards
Gururaja

guru <guru.naveen.TakeThisOut@gmail.com> writes:
> What are the causes for process going in to D state. (which is
> interruptible).

The process is doing an uninterruptible sleep in the kernel. The most
common cause of this is that it is waiting for a disk I/O-request to
complete.

> in my program i am using down(struct semaphore *) function which
> places process to uninterruptible state. so I am seeing Process in D
> state.

You could use down_interruptible instead, although that likely
wouldn't solve your problem.