Hi,
I have the following piece of code which is written for a device read
file_operation, I want a process to block till a packet queue becomes
non-zero in length...
.
.
.
set_current_state (TASK_INTERRUPTIBLE);
for (;!skb_queue_len (&p->pkt_queue);) {
schedule ();
if (signal_pending (current)) {
/* ouch! another doubt */
rv = -ERESTARTSYS;
goto ret;
}
}
.
.
.
ret:
set_current_state (TASK_RUNNING);
schedule ();
return rv;
}
.
.
.
I want to know the following:
1. does schedule return immediately, or blocks by shifting
CPU attention to another process (because we are not TASK_RUNNING)
2. if not, does this mean a busy wait
3. when schedule returns, are we TASK_RUNNING
Please comment on the above code.
Since I ensure that only one process will be waiting on a particular
queue, I do not want to use a wait queue.
Thanks in advance
--
Sudeep
--
Kernelnewbies: Help each other learn about the Linux kernel.
Archive: http://mail.nl.linux.org/kernelnewbies/
FAQ: http://kernelnewbies.org/faq/
