Re: [dpdk-dev] [PATCH v1 1/1] test/distributor: prevent return buffer overload

[David Hunt <david.hunt@intel.com>]

Hi Lukasz,

On 19/1/2021 3:59 AM, Lukasz Wojciechowski wrote:
> The distributor library implementation uses a cyclic queue to store
> packets returned from workers. These packets can be later collected
> with rte_distributor_returned_pkts() call.
> However the queue has limited capacity. It is able to contain only
> 127 packets (RTE_DISTRIB_RETURNS_MASK).
>
> Big burst tests sent 1024 packets in 32 packets bursts without waiting
> until they are processed by the distributor. In case when tests were
> run with big number of worker threads, it happened that more than
> 127 packets were returned from workers and put into cyclic queue.
> This caused packets to be dropped by the queue, making them impossible
> to be collected later with rte_distributor_returned_pkts() calls.
> However the test waited for all packets to be returned infinitely.
>
> This patch fixes the big burst test by not allowing more than
> queue capacity packets to be processed at the same time, making
> impossible to drop any packets.
> It also cleans up duplicated code in the same test.
>
> Bugzilla ID: 612
> Fixes: c0de0eb82e40 ("distributor: switch over to new API")
> Cc: david.hunt@intel.com
> Cc: stable@dpdk.org
>
> Signed-off-by: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>
> ---


This patch cleans up the code nicely, and it makes sense to return 
packets in the do..while. LGTM.


Reviewed-by: David Hunt <david.hunt@intel.com>