[PATCH] examples/l3fwd: fix Tx performance deteriorate

[Stephen Hemminger]

On Fri, 22 Nov 2024 15:13:36 +0800
Jie Hai <haijie1 at huawei.com> wrote:

> The application send packets only when the buffer is full, or the
> buffer is empty and the number of packets to be sent extends half
> of the buffer.
> 
> The change of MAX_PKT_BURST increases TX buffer size, while the
> default size of local cache on each lcore is 256, which not greater
> than the limit of transmitting. That would make the mbuf not on the
> local cache be frequently used and the performance deteriorates.
> 
> This problem can be solved by making the TX threshold smaller than
> the local cache size. For example, use the '--mbcache' parameter to
> make the local cache greater. This patch optimizes the default
> performance by lowering TX threshold.
> 
> Fixes: d5c4897ecfb2 ("examples/l3fwd: add option to set Rx burst size")
> 
> Signed-off-by: Jie Hai <haijie1 at huawei.com>

Do the other variants of l3fwd have the same problem?