Re: [PATCH dpdk] net/mlx5: add option to reduce Tx datapath compilation time

["Robin Jarry" <rjarry@redhat.com>]

Bruce Richardson, Apr 22, 2026 at 09:27:
> Out of interest, do you have any numbers for the performance delta between
> the release builds with and without the new flag? I'm just wondering if the
> flag can be the default to speed up builds generally?

The raw performance will depend on which offload features are enabled.
I have tested with the hardware I have at hand and these 3 TX offload
combinations:

0x10000: FAST_FREE
0x10020: FAST_FREE TCP_TSO
0x1008f: FAST_FREE TCP_TSO UDP_TSO UDP_CKSUM TCP_CKSUM IPV4_CKSUM VLAN_INSERT

MINIMAL_TX   TX_OFFLOADS    TX_FUNC                      NON_DROP_RATE
============ ============== ============================ ==============
off          0x10000        mlx5_tx_burst_none_empw      42.4M
off          0x10020        mlx5_tx_burst_mt_empw        39.4M
off          0x1008f        mlx5_tx_burst_sciv_empw      30.2M
on           0x10000        mlx5_tx_burst_full_noi_empw  36.2M
on           0x10020        mlx5_tx_burst_full_noi_empw  36.2M
on           0x1008f        mlx5_tx_burst_full_empw      30.2M

There is obviously something wrong with my patch. I need to make sure
the *no offload* case does not result in -15% of performance.

> [Not that it should affect me that much, I generally use
> -Denable_drivers flag when configuring my builds to only select the
> specific drivers I want]

I usually do this too but it turns out I *always* need mlx5 ;)