Re: Fatal Oops on boot with 2.4.0testX and recent GCC snapshots

From: Andreas Franck (
Date: Mon Dec 25 2000 - 07:29:20 EST

Hello Mike, hello linux-kernel hackers,

Mike Galbraith wrote:
> I wouldn't (not going to here;) spend a lot of time on it. The compiler
> has problems. It won't build glibc-2.2, and chokes horribly on ipchains.

Maybe, but after having spent several hours debugging now, I think it was
worth it: I am almost sure this is not a gcc bug, but a nasty race condition
involving the semaphore handling bdflush_init.

I figured out by spilling some printk's around in bdflush_init, which made
the bug magically disappear, what wasn't what I intended - but which gave me
a clearer impression of what's going on.

It seems that whyever, the cause for this failure is actually the down(sem)
call on a not yet up()'ed semaphore, and this is where it starts to get ugly.

->>>----------------------- Andreas Franck --------<<<-
---<<<---- --->>>---
->>>---- Keep smiling! ----------------------------<<<-
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