[dpdk-dev] [PATCH] net/vmxnet3: fix queue size changes

[Charles (Chas) Williams]

On 03/14/2017 12:11 PM, Jan Blunck wrote:
> On Mon, Mar 13, 2017 at 11:41 PM, Charles (Chas) Williams
> <ciwillia at brocade.com> wrote:
>> If the user reconfigures the queues size, then the previosly allocated
>> memzone may potentially be too small.  Instead, always free the old
>> memzone and allocate a new one.
>>
>> Fixes: dfaff37fc46d ("vmxnet3: import new vmxnet3 poll mode driver implementation")
>>
>> Signed-off-by: Chas Williams <ciwillia at brocade.com>
>> ---
>>  drivers/net/vmxnet3/vmxnet3_rxtx.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/vmxnet3/vmxnet3_rxtx.c b/drivers/net/vmxnet3/vmxnet3_rxtx.c
>> index 6649c3f..104e040 100644
>> --- a/drivers/net/vmxnet3/vmxnet3_rxtx.c
>> +++ b/drivers/net/vmxnet3/vmxnet3_rxtx.c
>> @@ -893,8 +893,8 @@ vmxnet3_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
>>
>>  /*
>>   * Create memzone for device rings. malloc can't be used as the physical address is
>> - * needed. If the memzone is already created, then this function returns a ptr
>> - * to the old one.
>> + * needed. If the memzone already exists, we free it since it may have been created
>> + * with a different size.
>>   */
>>  static const struct rte_memzone *
>>  ring_dma_zone_reserve(struct rte_eth_dev *dev, const char *ring_name,
>> @@ -909,7 +909,7 @@ ring_dma_zone_reserve(struct rte_eth_dev *dev, const char *ring_name,
>>
>>         mz = rte_memzone_lookup(z_name);
>>         if (mz)
>> -               return mz;
>> +               rte_memzone_free(mz);
>>
>>         return rte_memzone_reserve_aligned(z_name, ring_size,
>>                                            socket_id, 0, VMXNET3_RING_BA_ALIGN);
>
> Chas,
>
> Thanks for hunting this one down. Wouldn't the rte_memzone_free()
> better fit into vmxnet3_cmd_ring_release() ?

I don't care which way it goes.  I just did what is basically done in
gpa_zone_reserve() to match the "style".  Tracking the current ring size
and avoiding reallocating a potentially large chunk of memory seems like
a better idea.

> Also the ring_dma_zone_reserve() could get replaced by
> rte_eth_dma_zone_reserve() (see also

Yes, it probably should get changed to that along with tracking the size.