Re: slqb enables interrupts very early
From: Pekka Enberg
Date: Mon Jul 27 2009 - 03:44:33 EST
Sebastian Andrzej Siewior wrote:
I've checkout slab-2.6/linux-next and noticed that the interrupts are
enabled very early by accident. Please look at the following call stack:
start_kernel()
kmem_cache_init()
kmem_cache_open()
down_write(&slqb_lock);
__down_write()
__down_write_nested()
Now, __down_write_nested() protects its internal structure the follwing
way:
spin_lock_irq(&sem->wait_lock);
...
spin_unlock_irq(&sem->wait_lock);
so once we return, we return with interrupts on.
Indeed. Nick, do we need to take ->slqb_lock in kmem_cache_open()? A
quick read on the code suggests that we could just drop it.
Pekka
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