Re: [PATCH] Introduce nodemask_t ADT [0/7]

From: Zwane Mwaikambo
Date: Thu Mar 18 2004 - 20:37:12 EST


On Thu, 18 Mar 2004, Jesse Barnes wrote:

> On Thursday 18 March 2004 4:58 pm, Zwane Mwaikambo wrote:
> > > It probably shouldn't have anything to do with PCI directly either,
> > > so .... ;-) My former thought was that you might just want the most
> > > local memory for DMAing into.
> >
> > That knowledge should be in the dma api thing shouldn't it? But in it's
> > current incarnation i don't see how that's possible.
>
> Couldn't we mostly hide it under the covers (though obviously not in
> the intentionally remote case I mentioned earlier):

How about honouring DMA masks? Would this work with a 32bit DMA mask on a
node with memory above the 4G mark. This is for the more impaired systems
out there of course =)

> ===== arch/ia64/sn/io/machvec/pci_dma.c 1.28 vs edited =====
> --- 1.28/arch/ia64/sn/io/machvec/pci_dma.c Sun Mar 14 11:17:06 2004
> +++ edited/arch/ia64/sn/io/machvec/pci_dma.c Thu Mar 18 17:08:13 2004
> @@ -130,13 +130,11 @@
> device_sysdata = SN_DEVICE_SYSDATA(hwdev);
> vhdl = device_sysdata->vhdl;
>
> - /*
> - * Allocate the memory.
> - * FIXME: We should be doing alloc_pages_node for the node closest
> - * to the PCI device.
> - */
> - if (!(cpuaddr = (void *)__get_free_pages(GFP_ATOMIC, get_order(size))))
> + cpuaddr = alloc_pages_node(pci_to_node(hwdev), GFP_ATOMIC, (get_order(size)));
> + if (!cpuaddr)
> return NULL;
> +
> + cpuaddr = page_to_virt(cpuaddr);
>
> memset(cpuaddr, 0x0, size);
-
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