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Date: Fri, 17 May 2002 10:33:26 -0400
From: Jeff Garzik <jgarzik@mandrakesoft.com>
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To: "David S. Miller" <davem@redhat.com>
CC: ink@jurassic.park.msu.ru, andrew.grover@intel.com, mochel@osdl.org,
        Greg@kroah.com, linux-kernel@vger.kernel.org
Subject: Re: pci segments/domains
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David S. Miller wrote:

>   From: Jeff Garzik <jgarzik@mandrakesoft.com>
>   Date: Fri, 17 May 2002 10:24:39 -0400
>
>   I know -- that's what I mean by being more explicit.  sysdata would 
>   become a pointer to struct pci_domain.
>   
>No thanks, I want to say what the layout is for
>this object.  What pci_domain will end up doing is
>making for one more dereference to "arch private"
>state and that stinks for performance :-)
>


See my previous message from the other day... this would be defined in 
each arch's asm/pci.h, which eliminates this problem you describe.  Each 
arch maintainer would indeed decide how to define it, though over time 
I'm sure it would grow commonly-named struct members.

My main want is cosmetic -- call a spade a spade, so to speak. 
 s/sysdata/pci_domain/  But doing so opens the door to increased 
flexibility.  Later steps can add common members needed by pci-to-pci 
IOMMU tricks which are common to most platforms.

    Jeff