Re: [PATCH] x86/PCI: initialize PCI bus node numbers early

[Jesse Barnes]

On Fri, 10 Jul 2009 13:22:49 -0700
Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> wrote:

> On Fri, 10 Jul 2009 13:18:06 -0700
> Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> 
> > Jesse Barnes wrote:
> > > The current mp_bus_to_node array is initialized only by AMD
> > > specific code, since AMD platforms have registers that can be
> > > used for determining mode numbers.  On new Intel platforms it's
> > > necessary to initialize this array as well though, otherwise all
> > > PCI node numbers will be 0, when in fact they should be -1
> > > (indicating that I/O isn't tied to any particular node).
> > > 
> > > So move the mp_bus_to_node code into the common PCI code, and
> > > initialize it early with a default value of -1.  This may be
> > > overridden later by arch code (e.g. the AMD code).
> > > 
> > > With this change, PCI consistent memory and other node specific
> > > allocations (e.g. skbuff allocs) should occur on the "current"
> > > node. If, for performance reasons, applications want to be bound
> > > to specific nodes, they should open their devices only after being
> > > pinned to the CPU where they'll run, for maximum locality.
> > > 
> > > Any thoughts here Yinghai or Jesse?
> > > 
> > > 
> > >  include/asm/pci.h |    2 +
> > >  kernel/setup.c    |    2 +
> > >  pci/amd_bus.c     |   61
> > > +----------------------------------------- pci/common.c      |
> > > 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files
> > > changed, 83 insertions(+), 59 deletions(-)
> > > 
> > > Thanks,
> > 
> > could use
> > 
> > static int mp_bus_to_node[BUS_NR] = {
> >         [0 ... BUS_NR - 1] = -1
> > };
> > 
> > so we avoid to add pci_bus_to_node_init()
> 
> Ah yeah that would clean things up a bit...  Thanks.
> 

So something like this...

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