Re: [PATCH] irq: Add node_affinity CPU masks for smarter irqbalance hints

From: Andi Kleen
Date: Tue Nov 24 2009 - 15:35:47 EST


Eric Dumazet <eric.dumazet@xxxxxxxxx> writes:

> David Miller a écrit :
>> From: Eric Dumazet <eric.dumazet@xxxxxxxxx>
>> Date: Tue, 24 Nov 2009 19:26:15 +0100
>>
>>> It seems complex to me, maybe optimal thing would be to use a NUMA policy to
>>> spread vmalloc() allocations to all nodes to get a good bandwidth...
>>
>> vmalloc() and sk_buff's don't currently mix and I really don't see us
>> every allowing them to :-)
>
> I think Peter was referring to tx/rx rings buffers, not sk_buffs.
>
> They (ring buffers) are allocated with vmalloc() at driver init time.

They are typically allocated with dma_alloc_coherent(), which does
allocate a continuous area. In theory you could do interleaving
with IOMMus, but just putting it on the same node as the device
is probably better.

-Andi
--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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