> When I attempted to boot linux-2.5.8-pre1, I got a kernel
>BUG() for exit.c line 519.
>
That bug is hit when the schedule() returns. In the do_exit() case,
schedule is not supposed to return. After the current task is scheduled
out, it is destroyed. I guess that most of the freeing of the task's
resources is done in do_exit(), but I don't see where its kernel stack
is freed.
> The was a small change to to kernel/exit.c
>in 2.5.8-pre1 which deleted a kernel_lock() call. Restoring that line
>resulted in a kernel that booted fine.
>
I take it you don't have a copy of the BUG(). I was going to ask if
preemption was enabled, but I see that it was from another message. I
was guessing that preemption contributed to this, but now I know. The
lock_kernel() has 2 different effects here. It locks the kernel_flag,
AND it disables preemption. The correct fix here will probably be to
disable preemption, rather than readd the lock_kernel().
For the preemption gurus:
Is a preempt_disable() in do_exit() going to hurt anything? Shold we
selectively skip the preempt_disable() in schedule() if it was
schedule() called from do_exit()?
-- Dave Hansen haveblue@us.ibm.com- 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/