Re: CFQ + 2.6.13-rc4-RT-V0.7.52-02 = BUG: scheduling with irqs disabled

Jens Axboe
2005-08-24T17:47:09Z

On Wed, Aug 24 2005, Lee Revell wrote:
> Just found this in dmesg.
>
> BUG: scheduling with irqs disabled: libc6.postinst/0x20000000/13229
> caller is ___down_mutex+0xe9/0x1a0
> [<c029c1f9>] schedule+0x59/0xf0 (8)
> [<c029ced9>] ___down_mutex+0xe9/0x1a0 (28)
> [<c0221832>] cfq_exit_single_io_context+0x22/0xa0 (84)
> [<c02218ea>] cfq_exit_io_context+0x3a/0x50 (16)
> [<c021db84>] exit_io_context+0x64/0x70 (16)
> [<c011efda>] do_exit+0x5a/0x3e0 (20)
> [<c011f3ca>] do_group_exit+0x2a/0xb0 (24)
> [<c0103039>] syscall_call+0x7/0xb (20)

Hmm, Ingo I seem to remember you saying that the following construct:

local_irq_save(flags);
spin_lock(lock);

which is equivelant to spin_lock_irqsave() in mainline being illegal in
-RT, is that correct? This is what cfq uses right now for an exiting
task, as the above trace indicates.

--
Jens Axboe