Re: 2.3.6-pre1 posted

On 2008-07-22, Frantisek Hrbata <[email protected]> wrote:
> generally it is a bad idea to use GFP_ATOMIC for all allocations
> like dazuko did.  GFP_ATOMIC should be used only when it is really
> necessary, like in the irq where you can not block. With GFP_ATOMIC
> kernel has limited possibilities how to get memory(pages) for your
> allocation. So there is much bigger possibility that the allocation
> fails.

I've been reworking the locking to avoid mallocs while having a
lock. In many places, this is not proving to be easy.

But quite frankly, I was not aware that spinlocks were being used for
SMP. There is no reason that spinlocks are needed in *any* portion of
the Dazuko code. Dazuko uses locking primarily for inter-process
communication and very rarely for protecting critical sections.

I need to see what kinds of locks I am *supposed* to be using. Any
tips would be greatly appreciated. (ie. what types of locks may be
held while performing GFP_KERNEL memory allocation?)

John Ogness

-- 
Dazuko Maintainer