Re: [PATCH] BUG(): sched.c: Line 944

Robert Love
2002-09-18T04:39:53Z

On Tue, 2002-09-17 at 16:58, Steven Cole wrote:

> Sorry, it hung so badly that it didn't respond to that.

I fixed the hang. If you notice the problem, please do not laugh.

The attached patch, against 2.5.36, should work fine...

Robert Love

diff -urN linux-2.5.36/kernel/sched.c linux/kernel/sched.c
--- linux-2.5.36/kernel/sched.c Tue Sep 17 20:58:48 2002
+++ linux/kernel/sched.c Wed Sep 18 00:41:09 2002
@@ -940,9 +940,6 @@
struct list_head *queue;
int idx;

- if (unlikely(in_atomic()))
- BUG();
-
#if CONFIG_DEBUG_HIGHMEM
check_highmem_ptes();
#endif
@@ -950,8 +947,20 @@
preempt_disable();
prev = current;
rq = this_rq();
-
release_kernel_lock(prev);
+
+ /*
+ * Test if we are atomic. Since do_exit() needs to call into
+ * schedule() atomically, we ignore that for now. Otherwise,
+ * whine if we are scheduling when we should not be.
+ */
+ if (likely(current->state != TASK_ZOMBIE)) {
+ if (unlikely((preempt_count() & ~PREEMPT_ACTIVE) != 1)) {
+ printk(KERN_ERR "scheduling while non-atomic!\n");
+ dump_stack();
+ }
+ }
+
prev->sleep_timestamp = jiffies;
spin_lock_irq(&rq->lock);