Re: [RFC] i386: per-cpu mmconfig map

From: OGAWA Hirofumi
Date: Sun Dec 24 2006 - 12:47:07 EST


Hi,

Arjan van de Ven <arjan@xxxxxxxxxxxxx> writes:

>> [ Alternatively, we could make a per-cpu mapping area or something. Not
>> that it's probably worth it, but if we wanted to avoid all locking and
>> instead just disable preemption, that would be the way to go. --Linus ]
>>
>> This patch is a draft of Linus's suggestion. This seems work for me.
>> And this removes pci_config_lock in mmconfig access path, I think we
>> don't need lock on this path, although we need to disable IRQ.
>>
>> Comment?
>
> I like the idea and the implementation, I have just one concern:
> Does your schema still work if the Non-Maskable-Interrupt code uses
> config space? It may do that I suspect to deal with ECC memory errors ;(

I didn't notice the problem of NMI at all. However if NMI path use it,
pci_config_lock would be deadlock already. So I think NMI can't access
to PCI config... Hm...
--
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
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