On 10/29/2020 4:43 AM, Dharmik Thakkar wrote:

<...>

On Oct 27, 2020, at 1:42 AM, Zhou Zhenghua <zhenghuax.z...@intel.com> wrote:

When changing the number of forwarding cores in runtime, two issues may be
encountered:

  - If the setting nbcore little than current nbcore, the forwarding
    thread will still running on the extra cores. Therefore, trying to
    stop forwarding will hang testpmd, since it will wait for the extra
    cores to stop.

  - If the setting nbcore greate than actual nbcore, the newly added
    cores are not allocated resources.

This will face the problem of dynamic resource allocation, so it's not
allow to changes nbcore number when forwarding is running.

Fixes: 0c0db76f42ed ("app/testpmd: separate forward config setup from display")
Cc: bernard.iremon...@intel.com
Cc: sta...@dpdk.org

Signed-off-by: Zhou Zhenghua <zhenghuax.z...@intel.com>

> Hi Zhou,
>
> Although, I see that a few of the configuration options are checking for ’test_done’, I am wondering if it is truly required.
> Since, as per the documentation guidelines:
> 'Configuration changes only become active when forwarding is 
started/restarted.’
>
Yes documentation has it and I think that is what happens in below bullet 2 (increase core count).

But it is easy to reproduce the hung mentioned in the first bullet, I am for having this fix. And this won't contradict with the above document, the config options you can set will be taken account when forwarding is started/restarted, but this one won't be set because of added check, hence:
Acked-by: Ferruh Yigit <ferruh.yi...@intel.com>

@Zhou,
do you have any objection to remove bullet 2 while merging?

Reply via email to