RE: [PATCH net-next] bnx2x: dont use netdev_alloc_skb()

Vladislav Zolotarov
2010-10-12T09:12:54Z

> -----Original Message-----
> From: netdev-owner@vger.kernel.org [mailto:netdev-
> owner@vger.kernel.org] On Behalf Of Eric Dumazet
> Sent: Tuesday, October 12, 2010 7:16 AM
> To: Tom Herbert
> Cc: David Miller; netdev; Michael Chan; Eilon Greenstein
> Subject: Re: [PATCH net-next] bnx2x: dont use netdev_alloc_skb()
>
> Le lundi 11 octobre 2010 à 22:03 -0700, Tom Herbert a écrit :
> > On Mon, Oct 11, 2010 at 4:22 PM, Eric Dumazet
> <eric.dumazet@gmail.com> wrote:
> > > Le mardi 12 octobre 2010 à 01:03 +0200, Eric Dumazet a écrit :
> > >> netdev_alloc_skb() is a very wrong interface, really.
> > >>
> > >> We should remove/deprecate it.
> > >>
> > >> For multi queue devices, it makes more sense to allocate skb on
> local
> > >> node of the cpu handling RX interrupts. This allow each cpu to
> > >> manipulate its own slub/slab queues/structures without doing
> expensive
> > >> cross-node business.
> > >>
> > >> For non multi queue devices, IRQ affinity should be set so that a
> cpu
> > >> close to the device services interrupts. Even if not set, using
> > >> dev_alloc_skb() is faster.
> > >>
> > >> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> > >
> > > Or maybe revert :
> > >
> > > commit b30973f877fea1a3fb84e05599890fcc082a88e5
> > > Author: Christoph Hellwig <hch@lst.de>
> > > Date: Wed Dec 6 20:32:36 2006 -0800
> > >
> >
> > I second this revert. Node aware allocation by device's node makes
> > little sense on a multi-queue device and leads to mediocre
> > performance.
>
> Yes, I said this several time in the past, I believe time has come to
> get rid of it.
>
> I posted a patch some minutes ago, so you can review it and ack it ;)
>
> Thanks !

Eric, very nice patch, thanks. However Eilon is on vacation till tomorrow
and he is a responsible maintainer of the bnx2x, thus the final ACK should
be his.

Dave, if it can wait till tomorrow, I'd like to ask u to wait for Eilon's
final ACK.

Thanks,
vlad

>
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