From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [net-next-2.6 PATCH 3/3] ixgbe: Do not allocate too many
 netdev txqueues
Date: Fri, 26 Feb 2010 15:04:14 +0100
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	 <20100226091519.19796.82441.stgit@localhost.localdomain>
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Cc: davem@davemloft.net, netdev@vger.kernel.org, gospo@redhat.com,
	John Fastabend <john.r.fastabend@intel.com>
To: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
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Le vendredi 26 f=C3=A9vrier 2010 =C3=A0 01:15 -0800, Jeff Kirsher a =C3=
=A9crit :
> From: John Fastabend <john.r.fastabend@intel.com>
>=20
> Instead of allocating 128 struct netdev_queue per device, use the
> minimum value between 128 and the number of possible txq's, to
> reduce ram usage and "tc -s -d class shod dev .." output.
>=20
> This patch fixes Eric Dumazet's patch to set the TX queues to
> the correct minimum.
>=20
> Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> ---
>=20
>  drivers/net/ixgbe/ixgbe_main.c |   14 +++++++++++++-
>  1 files changed, 13 insertions(+), 1 deletions(-)
>=20
> diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe=
_main.c
> index 4a01022..a961da2 100644
> --- a/drivers/net/ixgbe/ixgbe_main.c
> +++ b/drivers/net/ixgbe/ixgbe_main.c
> @@ -5996,6 +5996,7 @@ static int __devinit ixgbe_probe(struct pci_dev=
 *pdev,
>  	const struct ixgbe_info *ii =3D ixgbe_info_tbl[ent->driver_data];
>  	static int cards_found;
>  	int i, err, pci_using_dac;
> +	unsigned int indices =3D num_possible_cpus();
>  #ifdef IXGBE_FCOE
>  	u16 device_caps;
>  #endif
> @@ -6034,7 +6035,18 @@ static int __devinit ixgbe_probe(struct pci_de=
v *pdev,
>  	pci_set_master(pdev);
>  	pci_save_state(pdev);
> =20
> -	netdev =3D alloc_etherdev_mq(sizeof(struct ixgbe_adapter), MAX_TX_Q=
UEUES);
> +	if (ii->mac =3D=3D ixgbe_mac_82598EB)
> +		indices =3D min_t(unsigned int, indices, IXGBE_MAX_RSS_INDICES);
> +	else
> +		indices =3D min_t(unsigned int, indices, IXGBE_MAX_FDIR_INDICES);
> +
> +	indices =3D max_t(unsigned int, indices, IXGBE_MAX_DCB_INDICES);
> +#ifdef IXGBE_FCOE
> +	indices +=3D min_t(unsigned int, num_possible_cpus(),
> +			 IXGBE_MAX_FCOE_INDICES);
> +#endif
> +	indices =3D min_t(unsigned int, indices, MAX_TX_QUEUES);
> +	netdev =3D alloc_etherdev_mq(sizeof(struct ixgbe_adapter), indices)=
;
>  	if (!netdev) {
>  		err =3D -ENOMEM;
>  		goto err_alloc_etherdev;
>=20

Thanks Jeff, but what is the reason for limiting to MAX_TX_QUEUES ?
Is it a hardware issue ?