Messages in this thread Patch in this message | | | Date | Tue, 3 Jul 2001 16:17:43 -0400 (EDT) | From | "Richard B. Johnson" <> | Subject | wait_event() problems <patch> |
| |
I have been trying to get the following to work:
atomic_t stop; struct wait_queue wait_queue_stuff, another_wait_queue; /* Initialized before use with init_wait_queue() */
kernel_thread() { for(;;) { if(atomic_read(stop)) interruptible_sleep_on(&wait_queue_stuff); do_regular_stuff(); } }
ioctl_start() { if(waitqueue_active(&wait_queue_stuff)) { atomic_set(&stop, 0); wake_up_interruptible(&wait_queue_stuff); } } ioctl_stop() { if(!waitqueue_active(&wait_queue_stuff)) { atomic_set(&stop, 1); wait_event(another_wait_queue, waitqueue_active(&wait_queue_stuff)); } }
The problem is that when ioctl_stop() is executed, the kernel thread never gets any CPU time so it remains stuck in "D" state forever.
Maybe I'm doing something wrong, but something seems to be broken. The following patch 'fixes' it.
--- linux-2.4.1/include/linux/sched.h.orig Tue Jul 3 15:14:07 2001 +++ linux-2.4.1/include/linux/sched.h Tue Jul 3 15:16:27 2001 @@ -763,6 +763,7 @@ set_current_state(TASK_UNINTERRUPTIBLE); \ if (condition) \ break; \ + current->policy = SCHED_YIELD; \ schedule(); \ } \ current->state = TASK_RUNNING; \
Cheers, Dick Johnson
Penguin : Linux version 2.4.1 on an i686 machine (799.53 BogoMips).
I was going to compile a list of innovations that could be attributed to Microsoft. Once I realized that Ctrl-Alt-Del was handled in the BIOS, I found that there aren't any.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |