Re: [patch] Real-Time Preemption, -RT-2.6.9-rc4-mm1-U8

[Ingo Molnar]

* Alexander Batyrshin <abatyrshin@xxxxxxxxxxxxx> wrote:

> used i386/defconfig

> BUG: semaphore recursion deadlock detected!
> .. current task khpsbpkt/723 is already holding c04610c0.

ok, this should be fixed in -U9.2.

> 2.
> if execute
> ``for i in `seq 1 9999`; do nohup bash >/dev/null 2>&1 & done'',
> then you'll get something like:
> [...skip...]
> Warning: dev (pts0) tty->count(16) != #fd's(8) in tty_open
> Warning: dev (pts0) tty->count(16) != #fd's(11) in tty_open

> I'v tested it against linux-2.6.9-rc4-mm1 => all was ok

i have trouble reproducing this myself. Can you still trigger it under
-U9.2? If yes then could you check whether this still happens with a the
same .config but with CONFIG_SMP turned off? This smells like a locking
bug/breakage in the tty layer that we dont detect. You have all the
relevant debug options turned on, correct? (DEBUG_PREEMPT and
RWSEM_DEADLOCK_DETECT)

	Ingo
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