[dpdk-dev] [PATCH v2 4/4] net/i40e: enable deferred queue setup

[Bruce Richardson]

On Fri, Mar 16, 2018 at 09:54:03AM +0000, Ananyev, Konstantin wrote:
> 
> 
> > -----Original Message-----
> > From: Zhang, Qi Z
> > Sent: Friday, March 16, 2018 12:52 AM
> > To: Ananyev, Konstantin <konstantin.ananyev at intel.com>; thomas at monjalon.net
> > Cc: dev at dpdk.org; Xing, Beilei <beilei.xing at intel.com>; Wu, Jingjing <jingjing.wu at intel.com>; Lu, Wenzhuo <wenzhuo.lu at intel.com>
> > Subject: RE: [dpdk-dev] [PATCH v2 4/4] net/i40e: enable deferred queue setup
> > 
> > 
> > 
> > > -----Original Message-----
> > > From: Ananyev, Konstantin
> > > Sent: Thursday, March 15, 2018 11:22 PM
> > > To: Zhang, Qi Z <qi.z.zhang at intel.com>; thomas at monjalon.net
> > > Cc: dev at dpdk.org; Xing, Beilei <beilei.xing at intel.com>; Wu, Jingjing
> > > <jingjing.wu at intel.com>; Lu, Wenzhuo <wenzhuo.lu at intel.com>
> > > Subject: RE: [dpdk-dev] [PATCH v2 4/4] net/i40e: enable deferred queue
> > > setup
> > >
> > >
> > >
> > > > -----Original Message-----
> > > > From: Zhang, Qi Z
> > > > Sent: Thursday, March 15, 2018 2:30 PM
> > > > To: Ananyev, Konstantin <konstantin.ananyev at intel.com>;
> > > > thomas at monjalon.net
> > > > Cc: dev at dpdk.org; Xing, Beilei <beilei.xing at intel.com>; Wu, Jingjing
> > > > <jingjing.wu at intel.com>; Lu, Wenzhuo <wenzhuo.lu at intel.com>
> > > > Subject: RE: [dpdk-dev] [PATCH v2 4/4] net/i40e: enable deferred queue
> > > > setup
> > > >
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: Ananyev, Konstantin
> > > > > Sent: Thursday, March 15, 2018 9:23 PM
> > > > > To: Zhang, Qi Z <qi.z.zhang at intel.com>; thomas at monjalon.net
> > > > > Cc: dev at dpdk.org; Xing, Beilei <beilei.xing at intel.com>; Wu, Jingjing
> > > > > <jingjing.wu at intel.com>; Lu, Wenzhuo <wenzhuo.lu at intel.com>
> > > > > Subject: RE: [dpdk-dev] [PATCH v2 4/4] net/i40e: enable deferred
> > > > > queue setup
> > > > >
> > > > >
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Zhang, Qi Z
> > > > > > Sent: Thursday, March 15, 2018 3:22 AM
> > > > > > To: Ananyev, Konstantin <konstantin.ananyev at intel.com>;
> > > > > > thomas at monjalon.net
> > > > > > Cc: dev at dpdk.org; Xing, Beilei <beilei.xing at intel.com>; Wu,
> > > > > > Jingjing <jingjing.wu at intel.com>; Lu, Wenzhuo
> > > > > > <wenzhuo.lu at intel.com>
> > > > > > Subject: RE: [dpdk-dev] [PATCH v2 4/4] net/i40e: enable deferred
> > > > > > queue setup
> > > > > >
> > > > > >
> > > > > >
> > > > > > > -----Original Message-----
> > > > > > > From: Ananyev, Konstantin
> > > > > > > Sent: Wednesday, March 14, 2018 8:36 PM
> > > > > > > To: Zhang, Qi Z <qi.z.zhang at intel.com>; thomas at monjalon.net
> > > > > > > Cc: dev at dpdk.org; Xing, Beilei <beilei.xing at intel.com>; Wu,
> > > > > > > Jingjing <jingjing.wu at intel.com>; Lu, Wenzhuo
> > > > > > > <wenzhuo.lu at intel.com>; Zhang, Qi Z <qi.z.zhang at intel.com>
> > > > > > > Subject: RE: [dpdk-dev] [PATCH v2 4/4] net/i40e: enable deferred
> > > > > > > queue setup
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > > -----Original Message-----
> > > > > > > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Qi Zhang
> > > > > > > > Sent: Friday, March 2, 2018 4:13 AM
> > > > > > > > To: thomas at monjalon.net
> > > > > > > > Cc: dev at dpdk.org; Xing, Beilei <beilei.xing at intel.com>; Wu,
> > > > > > > > Jingjing <jingjing.wu at intel.com>; Lu, Wenzhuo
> > > > > > > > <wenzhuo.lu at intel.com>; Zhang,
> > > > > > > Qi
> > > > > > > > Z <qi.z.zhang at intel.com>
> > > > > > > > Subject: [dpdk-dev] [PATCH v2 4/4] net/i40e: enable deferred
> > > > > > > > queue setup
> > > > > > > >
> > > > > > > > Expose the deferred queue configuration capability and enhance
> > > > > > > > i40e_dev_[rx|tx]_queue_[setup|release] to handle the situation
> > > > > > > > when device already started.
> > > > > > > >
> > > > > > > > Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
> > > > > > > > ---
> > > > > > > >  drivers/net/i40e/i40e_ethdev.c |  6 ++++
> > > > > > > >  drivers/net/i40e/i40e_rxtx.c   | 62
> > > > > > > ++++++++++++++++++++++++++++++++++++++++--
> > > > > > > >  2 files changed, 66 insertions(+), 2 deletions(-)
> > > > > > > >
> > > > > > > > diff --git a/drivers/net/i40e/i40e_ethdev.c
> > > > > > > > b/drivers/net/i40e/i40e_ethdev.c index 06b0f03a1..843a0c42a
> > > > > > > > 100644
> > > > > > > > --- a/drivers/net/i40e/i40e_ethdev.c
> > > > > > > > +++ b/drivers/net/i40e/i40e_ethdev.c
> > > > > > > > @@ -3195,6 +3195,12 @@ i40e_dev_info_get(struct rte_eth_dev
> > > > > *dev,
> > > > > > > struct rte_eth_dev_info *dev_info)
> > > > > > > >  		DEV_TX_OFFLOAD_GRE_TNL_TSO |
> > > > > > > >  		DEV_TX_OFFLOAD_IPIP_TNL_TSO |
> > > > > > > >  		DEV_TX_OFFLOAD_GENEVE_TNL_TSO;
> > > > > > > > +	dev_info->deferred_queue_config_capa =
> > > > > > > > +		DEV_DEFERRED_RX_QUEUE_SETUP |
> > > > > > > > +		DEV_DEFERRED_TX_QUEUE_SETUP |
> > > > > > > > +		DEV_DEFERRED_RX_QUEUE_RELEASE |
> > > > > > > > +		DEV_DEFERRED_TX_QUEUE_RELEASE;
> > > > > > > > +
> > > > > > > >  	dev_info->hash_key_size = (I40E_PFQF_HKEY_MAX_INDEX +
> > > 1) *
> > > > > > > >  						sizeof(uint32_t);
> > > > > > > >  	dev_info->reta_size = pf->hash_lut_size; diff --git
> > > > > > > > a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
> > > > > > > > index
> > > > > > > > 1217e5a61..e5f532cf7 100644
> > > > > > > > --- a/drivers/net/i40e/i40e_rxtx.c
> > > > > > > > +++ b/drivers/net/i40e/i40e_rxtx.c
> > > > > > > > @@ -1712,6 +1712,7 @@ i40e_dev_rx_queue_setup(struct
> > > > > rte_eth_dev
> > > > > > > *dev,
> > > > > > > >  	uint16_t len, i;
> > > > > > > >  	uint16_t reg_idx, base, bsf, tc_mapping;
> > > > > > > >  	int q_offset, use_def_burst_func = 1;
> > > > > > > > +	int ret = 0;
> > > > > > > >
> > > > > > > >  	if (hw->mac.type == I40E_MAC_VF || hw->mac.type ==
> > > > > > > I40E_MAC_X722_VF) {
> > > > > > > >  		vf =
> > > I40EVF_DEV_PRIVATE_TO_VF(dev->data->dev_private);
> > > > > > > > @@ -1841,6 +1842,25 @@ i40e_dev_rx_queue_setup(struct
> > > > > rte_eth_dev
> > > > > > > *dev,
> > > > > > > >  			rxq->dcb_tc = i;
> > > > > > > >  	}
> > > > > > > >
> > > > > > > > +	if (dev->data->dev_started) {
> > > > > > > > +		ret = i40e_rx_queue_init(rxq);
> > > > > > > > +		if (ret != I40E_SUCCESS) {
> > > > > > > > +			PMD_DRV_LOG(ERR,
> > > > > > > > +				    "Failed to do RX queue initialization");
> > > > > > > > +			return ret;
> > > > > > > > +		}
> > > > > > > > +		if (ad->rx_vec_allowed)
> > > > > > >
> > > > > > > Better to check what rx function is installed right now.
> > > > > > Yes, it should be fixed, need to return fail if any conflict
> > > > > > >
> > > > > > > > +			i40e_rxq_vec_setup(rxq);
> > > > > > > > +		if (!rxq->rx_deferred_start) {
> > > > > > > > +			ret = i40e_dev_rx_queue_start(dev, queue_idx);
> > > > > > >
> > > > > > > I don't think it is a good idea to start/stop queue inside
> > > > > > > queue_setup/queue_release.
> > > > > > > There is special API (queue_start/queue_stop) to do this.
> > > > > >
> > > > > > The idea is if dev already started, the queue is supposed to be
> > > > > > started
> > > > > automatically after queue_setup.
> > > > >
> > > > > Why is that?
> > > > Because device is already started, its like a running conveyor belt, anything
> > > you put or replace on it just moves automatically.
> > >
> > > Why is that? :)
> > > You do break existing behavior.
> > > Right now it possible to do:
> > > queue_setup(); queue_setup();
> > > for the same queue.
> > > With you patch is not any more
> > Why not?
> > I think with my patch,
> > It assumes we can run below scenario on the same queue.
> > (note, I assume queue_stop/start has been moved from i40e to ethedev layer already.)
> > queue_setup + queue_setup + dev_start + queue_setup + queue_setup,
> 
> Because you can't do queue_setup() on already started queue.
> So if you do start() inside setup() second setup() should fail.
> 
> > queue_stop/start are handled inside queue_setup automatically after dev_started?
> 
> Again - I don't see any advantages to change existing API behavior and introduce implicit
> start/stop inside setup.
> It only introduce extra confusion for the users.
> So I still think we better keep existing behavior.
> Konstantin
> 
+1 for keeping existing behaviour unless there is a compelling reason to
change.