On Tue, Oct 18, 2016 at 2:49 PM, Ilya Maximets <i.maximets at samsung.com>
wrote:
> On 18.10.2016 15:28, Jan Blunck wrote:
>> If the application already configured queues the PMD should not
>> silently claim ownership and reset them.
>>
>> What exactly is the problem when changing MTU? This works fine from
>> what I can tell.
>
> Following scenario leads to APP PANIC:
>
> 1. mempool_1 = rte_mempool_create()
> 2. rte_eth_rx_queue_setup(bond0, ..., mempool_1);
> 3. rte_eth_dev_start(bond0);
> 4. mempool_2 = rte_mempool_create();
> 5. rte_eth_dev_stop(bond0);
> 6. rte_eth_rx_queue_setup(bond0, ..., mempool_2);
> 7. rte_eth_dev_start(bond0);
> * RX queues still use 'mempool_1' because reconfiguration doesn't
> affect them. *
> 8. rte_mempool_free(mempool_1);
> 9. On any rx operation we'll get PANIC because of using freed
> 'mempool_1':
> PANIC in rte_mempool_get_ops():
> assert "(ops_index >= 0) && (ops_index < RTE_MEMPOOL_MAX_OPS_IDX)"
> failed
>
> You may just start OVS 2.6 with DPDK bonding device and attempt to change MTU
> via 'mtu_request'.
> Bug is easily reproducible.
>
I see. I'm not 100% that this is expected to work without leaking the
driver's queues though. The driver is allowed to do allocations in
its rx_queue_setup() function that are being freed via
rx_queue_release() later. But rx_queue_release() is only called if you
reconfigure the
device with 0 queues. From what I understand there is no other way to
reconfigure a device to use another mempool.
But ... even that wouldn't work with the bonding driver right now: the
bonding master only configures the slaves during startup. I can put
that on my todo list.
Coming back to your original problem: changing the MTU for the bond
does work through rte_eth_dev_set_mtu() for slaves supporting that. In
any other case you could (re-)configure rxmode.max_rx_pkt_len (and
jumbo_frame / enable_scatter accordingly). This does work without a
call to rte_eth_rx_queue_setup().
Hope this helps,
Jan
> Best regards, Ilya Maximets.
>
>>
>> On Wed, Sep 7, 2016 at 2:28 PM, Ilya Maximets <i.maximets at samsung.com>
>> 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 at dpdk.org>
>>> Signed-off-by: Ilya Maximets <i.maximets at 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
>>>
>>
>>
>>
