Re: [PATCH] NUMA aware allocation of transmit and receive buffersfor e1000

From: Andrew Morton
Date: Wed May 18 2005 - 00:03:42 EST


Christoph Lameter <christoph@xxxxxxxxxxx> wrote:
>
> On Tue, 17 May 2005, David S. Miller wrote:
>
> > > Because physically contiguous memory is usually better than virtually
> > > contiguous memory? Any reason that physically contiguous memory will
> > > break the driver?
> >
> > The issue is whether size can end up being too large for
> > kmalloc() to satisfy, whereas vmalloc() would be able to
> > handle it.
>
> Oww.. We need a NUMA aware vmalloc for this?

I think the e1000 driver is being a bit insane there. I figure that
sizeof(struct e1000_buffer) is 28 on 64-bit, so even with 4k pagesize we'll
always succeed in being able to support a 32k/32 = 1024-entry Tx ring.

Is there any real-world reason for wanting larger ring sizes than that?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/