Re: [dpdk-stable] [dpdk-dev] [PATCH] Revert "bonding: use existing enslaved device queues"

[Bruce Richardson <bruce.richardson@intel.com>]

On Wed, Oct 12, 2016 at 04:24:54PM +0300, Ilya Maximets wrote:
> On 07.10.2016 05:02, Eric Kinzie wrote:
> > On Wed Sep 07 15:28:10 +0300 2016, Ilya Maximets wrote:
> >> This reverts commit 5b7bb2bda5519b7800f814df64d4e015282140e5.
> >>
> >> It is necessary to reconfigure all queues every time because configuration
> >> can be changed.
> >>
> >> For example, if we're reconfiguring bonding device with new memory pool,
> >> already configured queues will still use the old one. And if the old
> >> mempool be freed, application likely will panic in attempt to use
> >> freed mempool.
> >>
> >> This happens when we use the bonding device with OVS 2.6 while MTU
> >> reconfiguration:
> >>
> >> PANIC in rte_mempool_get_ops():
> >> assert "(ops_index >= 0) && (ops_index < RTE_MEMPOOL_MAX_OPS_IDX)" failed
> >>
> >> Cc: <stable@dpdk.org>
> >> Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
> >> ---
> >>  drivers/net/bonding/rte_eth_bond_pmd.c | 10 ++--------
> >>  1 file changed, 2 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/drivers/net/bonding/rte_eth_bond_pmd.c b/drivers/net/bonding/rte_eth_bond_pmd.c
> >> index b20a272..eb5b6d1 100644
> >> --- a/drivers/net/bonding/rte_eth_bond_pmd.c
> >> +++ b/drivers/net/bonding/rte_eth_bond_pmd.c
> >> @@ -1305,8 +1305,6 @@ slave_configure(struct rte_eth_dev *bonded_eth_dev,
> >>  	struct bond_rx_queue *bd_rx_q;
> >>  	struct bond_tx_queue *bd_tx_q;
> >>  
> >> -	uint16_t old_nb_tx_queues = slave_eth_dev->data->nb_tx_queues;
> >> -	uint16_t old_nb_rx_queues = slave_eth_dev->data->nb_rx_queues;
> >>  	int errval;
> >>  	uint16_t q_id;
> >>  
> >> @@ -1347,9 +1345,7 @@ slave_configure(struct rte_eth_dev *bonded_eth_dev,
> >>  	}
> >>  
> >>  	/* Setup Rx Queues */
> >> -	/* Use existing queues, if any */
> >> -	for (q_id = old_nb_rx_queues;
> >> -	     q_id < bonded_eth_dev->data->nb_rx_queues; q_id++) {
> >> +	for (q_id = 0; q_id < bonded_eth_dev->data->nb_rx_queues; q_id++) {
> >>  		bd_rx_q = (struct bond_rx_queue *)bonded_eth_dev->data->rx_queues[q_id];
> >>  
> >>  		errval = rte_eth_rx_queue_setup(slave_eth_dev->data->port_id, q_id,
> >> @@ -1365,9 +1361,7 @@ slave_configure(struct rte_eth_dev *bonded_eth_dev,
> >>  	}
> >>  
> >>  	/* Setup Tx Queues */
> >> -	/* Use existing queues, if any */
> >> -	for (q_id = old_nb_tx_queues;
> >> -	     q_id < bonded_eth_dev->data->nb_tx_queues; q_id++) {
> >> +	for (q_id = 0; q_id < bonded_eth_dev->data->nb_tx_queues; q_id++) {
> >>  		bd_tx_q = (struct bond_tx_queue *)bonded_eth_dev->data->tx_queues[q_id];
> >>  
> >>  		errval = rte_eth_tx_queue_setup(slave_eth_dev->data->port_id, q_id,
> >> -- 
> >> 2.7.4
> >>
> > 
> > NAK
> > 
> > There are still some users of this code.  Let's give them a chance to
> > comment before removing it.
> 
> Hi Eric,
> 
> Are these users in CC-list? If not, could you, please, add them?
> This patch awaits in mail-list already more than a month. I think, it's enough
> time period for all who wants to say something. Patch fixes a real bug that
> prevent using of DPDK bonding in all applications that reconfigures devices
> in runtime including OVS.
> 
Agreed.

Eric, does reverting this patch cause you problems directly, or is your concern
just with regards to potential impact to others?

Thanks,
/Bruce