From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from na01-by2-obe.outbound.protection.outlook.com (mail-by2on0137.outbound.protection.outlook.com [207.46.100.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 5DC281A0286 for ; Thu, 3 Dec 2015 08:40:48 +1100 (AEDT) Message-ID: <1449092431.29246.156.camel@freescale.com> Subject: Re: [net-next v4 4/8] dpaa_eth: add driver's Tx queue selection From: Scott Wood To: , CC: , , , , , , , , , Date: Wed, 2 Dec 2015 15:40:31 -0600 In-Reply-To: <1446485500-9782-5-git-send-email-madalin.bucur@freescale.com> References: <1446485500-9782-1-git-send-email-madalin.bucur@freescale.com> <1446485500-9782-5-git-send-email-madalin.bucur@freescale.com> Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2015-11-02 at 19:31 +0200, Madalin Bucur wrote: > Allow the selection of the transmission queue based on the CPU id. Explain why. > > Signed-off-by: Madalin Bucur > --- > drivers/net/ethernet/freescale/dpaa/Kconfig | 10 ++++++++++ > drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 3 +++ > drivers/net/ethernet/freescale/dpaa/dpaa_eth.h | 6 ++++++ > drivers/net/ethernet/freescale/dpaa/dpaa_eth_common.c | 8 ++++++++ > drivers/net/ethernet/freescale/dpaa/dpaa_eth_common.h | 4 ++++ > 5 files changed, 31 insertions(+) > > diff --git a/drivers/net/ethernet/freescale/dpaa/Kconfig > b/drivers/net/ethernet/freescale/dpaa/Kconfig > index 022d5aa..2577aac 100644 > --- a/drivers/net/ethernet/freescale/dpaa/Kconfig > +++ b/drivers/net/ethernet/freescale/dpaa/Kconfig > @@ -11,6 +11,16 @@ menuconfig FSL_DPAA_ETH > > if FSL_DPAA_ETH > > +config FSL_DPAA_ETH_USE_NDO_SELECT_QUEUE > + bool "Use driver's Tx queue selection mechanism" > + default y > + ---help--- > + The DPAA Ethernet driver defines a ndo_select_queue() callback > for optimal selection > + of the egress FQ. That will override the XPS support for this > netdevice. > + If for whatever reason you want to be in control of the egress FQ > -to-CPU selection and mapping, > + or simply don't want to use the driver's ndo_select_queue() > callback, then unselect this > + and use the standard XPS support instead. Is there a use case for needing this to be configurable? > diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > index 31d55b4..894f1a7 100644 > --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c > @@ -390,6 +390,9 @@ static const struct net_device_ops dpa_private_ops = { > .ndo_get_stats64 = dpa_get_stats64, > .ndo_set_mac_address = dpa_set_mac_address, > .ndo_validate_addr = eth_validate_addr, > +#ifdef CONFIG_FSL_DPAA_ETH_USE_NDO_SELECT_QUEUE > + .ndo_select_queue = dpa_select_queue, > +#endif > .ndo_change_mtu = dpa_change_mtu, > .ndo_set_rx_mode = dpa_set_rx_mode, > .ndo_init = dpa_ndo_init, > diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.h > b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.h > index 1ba6617..87577cf 100644 > --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.h > +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.h > @@ -420,9 +420,15 @@ static inline void _dpa_assign_wq(struct dpa_fq *fq) > } > } > > +#ifdef CONFIG_FSL_DPAA_ETH_USE_NDO_SELECT_QUEUE > +/* Use in lieu of skb_get_queue_mapping() */ > +#define dpa_get_queue_mapping(skb) \ > + raw_smp_processor_id() > +#else > /* Use the queue selected by XPS */ > #define dpa_get_queue_mapping(skb) \ > skb_get_queue_mapping(skb) > +#endif Why is this necessary? Shouldn't providing a custom .ndo_select_queue() be sufficient to ensure that skb_get_queue_mapping() returns the same thing? And if this goes away, it's just a matter of a function pointer, so if it does need to be configurable it could be a runtime option. -Scott