The mlx5 Tx datapath compiles 42 variants of the burst function, each a specialization of mlx5_tx_burst_tmpl() with a different combination of offload flags. The compiler must instantiate and optimize the entire 3800+ line template for every variant, which dominates build time for all the code base.
When MLX5_MINIMAL_TX is defined, only 11 variants are compiled instead of 42. Two new "full without inline" superset variants (full_noi and full_noi_empw) are introduced to satisfy the selection algorithm constraint that the INLINE bit must match exactly between request and variant. The remaining 9 variants are existing ones that already cover all reachable combinations of the EMPW, MPW, INLINE and TXPP flags. The selection function is unchanged. At runtime, it picks the best matching variant from whatever is available. With the minimal set, each selected variant may include a few unnecessary offload checks compared to the precisely-tailored original, which has negligible impact on performance since modern branch predictors handle static never-taken branches well. Compilation times (MM:SS) measured on Intel Core Ultra 7 165U with GCC 16.0.1: FILE BUILD BEFORE AFTER DELTA ================= ============== ======== ======= =============== mlx5_tx_mpw.c debug 00:31 00:22 -00:09 (-29.0%) mlx5_tx_txpp.c 00:39 00:25 -00:14 (-35.9%) mlx5_tx_empw.c 01:11 00:19 -00:52 (-73.2%) mlx5_tx_nompw.c 01:13 00:16 -00:57 (-78.1%) ----------------- -------------- -------- ------- --------------- mlx5_tx_mpw.c debug+asan 03:15 02:45 -00:30 (-15.4%) mlx5_tx_txpp.c *06:28* 03:13 -03:15 (-50.3%) mlx5_tx_empw.c *12:07* 01:55 -10:12 (-84.2%) mlx5_tx_nompw.c *12:54* 01:45 -11:09 (-86.4%) ----------------- -------------- -------- ------- --------------- mlx5_tx_mpw.c release 00:12 00:09 -00:03 (-25.0%) mlx5_tx_txpp.c 00:31 00:24 -00:07 (-22.6%) mlx5_tx_empw.c 00:32 00:18 -00:14 (-43.8%) mlx5_tx_nompw.c 00:34 00:16 -00:18 (-52.9%) ----------------- -------------- -------- ------- --------------- mlx5_tx_mpw.c release+asan 00:25 00:23 -00:02 (-8.0%) mlx5_tx_empw.c 01:24 00:42 -00:42 (-50.0%) mlx5_tx_txpp.c 01:32 00:59 -00:33 (-35.9%) mlx5_tx_nompw.c 01:38 00:37 -01:01 (-62.2%) To enable, pass -DMLX5_MINIMAL_TX via c_args: meson setup build -Dc_args='-DMLX5_MINIMAL_TX' Signed-off-by: Robin Jarry <[email protected]> --- drivers/net/mlx5/mlx5_tx.c | 23 +++++++++++++++++++++++ drivers/net/mlx5/mlx5_tx.h | 12 ++++++++++++ drivers/net/mlx5/mlx5_tx_empw.c | 10 ++++++++++ drivers/net/mlx5/mlx5_tx_mpw.c | 2 ++ drivers/net/mlx5/mlx5_tx_nompw.c | 9 +++++++++ drivers/net/mlx5/mlx5_tx_txpp.c | 2 ++ 6 files changed, 58 insertions(+) diff --git a/drivers/net/mlx5/mlx5_tx.c b/drivers/net/mlx5/mlx5_tx.c index 94644bc3b9e2..a395577bb7e6 100644 --- a/drivers/net/mlx5/mlx5_tx.c +++ b/drivers/net/mlx5/mlx5_tx.c @@ -294,6 +294,14 @@ MLX5_TXOFF_INFO(full_empw, MLX5_TXOFF_CONFIG_INLINE | MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA | MLX5_TXOFF_CONFIG_EMPW) +#ifdef MLX5_MINIMAL_TX +MLX5_TXOFF_INFO(full_noi_empw, + MLX5_TXOFF_CONFIG_MULTI | MLX5_TXOFF_CONFIG_TSO | + MLX5_TXOFF_CONFIG_SWP | MLX5_TXOFF_CONFIG_CSUM | + MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA | + MLX5_TXOFF_CONFIG_EMPW) +#else + MLX5_TXOFF_INFO(none_empw, MLX5_TXOFF_CONFIG_NONE | MLX5_TXOFF_CONFIG_EMPW) @@ -355,6 +363,8 @@ MLX5_TXOFF_INFO(iv_empw, MLX5_TXOFF_CONFIG_INLINE | MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA | MLX5_TXOFF_CONFIG_EMPW) +#endif /* !MLX5_MINIMAL_TX */ + MLX5_TXOFF_INFO(full_ts_nompw, MLX5_TXOFF_CONFIG_FULL | MLX5_TXOFF_CONFIG_TXPP) @@ -374,6 +384,7 @@ MLX5_TXOFF_INFO(full_ts_noi, MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA | MLX5_TXOFF_CONFIG_TXPP | MLX5_TXOFF_CONFIG_EMPW) +#ifndef MLX5_MINIMAL_TX MLX5_TXOFF_INFO(none_ts, MLX5_TXOFF_CONFIG_NONE | MLX5_TXOFF_CONFIG_TXPP | MLX5_TXOFF_CONFIG_EMPW) @@ -392,6 +403,7 @@ MLX5_TXOFF_INFO(mtiv_ts, MLX5_TXOFF_CONFIG_INLINE | MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA | MLX5_TXOFF_CONFIG_TXPP | MLX5_TXOFF_CONFIG_EMPW) +#endif MLX5_TXOFF_INFO(full, MLX5_TXOFF_CONFIG_MULTI | MLX5_TXOFF_CONFIG_TSO | @@ -399,6 +411,13 @@ MLX5_TXOFF_INFO(full, MLX5_TXOFF_CONFIG_INLINE | MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA) +#ifdef MLX5_MINIMAL_TX +MLX5_TXOFF_INFO(full_noi, + MLX5_TXOFF_CONFIG_MULTI | MLX5_TXOFF_CONFIG_TSO | + MLX5_TXOFF_CONFIG_SWP | MLX5_TXOFF_CONFIG_CSUM | + MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA) +#else + MLX5_TXOFF_INFO(none, MLX5_TXOFF_CONFIG_NONE) @@ -460,6 +479,8 @@ MLX5_TXOFF_INFO(iv, MLX5_TXOFF_CONFIG_INLINE | MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA) +#endif /* !MLX5_MINIMAL_TX */ + MLX5_TXOFF_INFO(none_mpw, MLX5_TXOFF_CONFIG_NONE | MLX5_TXOFF_CONFIG_EMPW | MLX5_TXOFF_CONFIG_MPW) @@ -473,9 +494,11 @@ MLX5_TXOFF_INFO(mc_mpw, MLX5_TXOFF_CONFIG_MULTI | MLX5_TXOFF_CONFIG_CSUM | MLX5_TXOFF_CONFIG_EMPW | MLX5_TXOFF_CONFIG_MPW) +#ifndef MLX5_MINIMAL_TX MLX5_TXOFF_INFO(i_mpw, MLX5_TXOFF_CONFIG_INLINE | MLX5_TXOFF_CONFIG_EMPW | MLX5_TXOFF_CONFIG_MPW) +#endif }; /** diff --git a/drivers/net/mlx5/mlx5_tx.h b/drivers/net/mlx5/mlx5_tx.h index 016dba0b03c6..db55355abdd9 100644 --- a/drivers/net/mlx5/mlx5_tx.h +++ b/drivers/net/mlx5/mlx5_tx.h @@ -244,6 +244,9 @@ int mlx5_tx_burst_mode_get(struct rte_eth_dev *dev, uint16_t tx_queue_id, /* mlx5_tx_empw.c */ MLX5_TXOFF_PRE_DECL(full_empw); +#ifdef MLX5_MINIMAL_TX +MLX5_TXOFF_PRE_DECL(full_noi_empw); +#else MLX5_TXOFF_PRE_DECL(none_empw); MLX5_TXOFF_PRE_DECL(md_empw); MLX5_TXOFF_PRE_DECL(mt_empw); @@ -258,10 +261,14 @@ MLX5_TXOFF_PRE_DECL(sciv_empw); MLX5_TXOFF_PRE_DECL(i_empw); MLX5_TXOFF_PRE_DECL(v_empw); MLX5_TXOFF_PRE_DECL(iv_empw); +#endif /* mlx5_tx_nompw.c */ MLX5_TXOFF_PRE_DECL(full); +#ifdef MLX5_MINIMAL_TX +MLX5_TXOFF_PRE_DECL(full_noi); +#else MLX5_TXOFF_PRE_DECL(none); MLX5_TXOFF_PRE_DECL(md); MLX5_TXOFF_PRE_DECL(mt); @@ -276,6 +283,7 @@ MLX5_TXOFF_PRE_DECL(sciv); MLX5_TXOFF_PRE_DECL(i); MLX5_TXOFF_PRE_DECL(v); MLX5_TXOFF_PRE_DECL(iv); +#endif /* mlx5_tx_txpp.c */ @@ -283,17 +291,21 @@ MLX5_TXOFF_PRE_DECL(full_ts_nompw); MLX5_TXOFF_PRE_DECL(full_ts_nompwi); MLX5_TXOFF_PRE_DECL(full_ts); MLX5_TXOFF_PRE_DECL(full_ts_noi); +#ifndef MLX5_MINIMAL_TX MLX5_TXOFF_PRE_DECL(none_ts); MLX5_TXOFF_PRE_DECL(mdi_ts); MLX5_TXOFF_PRE_DECL(mti_ts); MLX5_TXOFF_PRE_DECL(mtiv_ts); +#endif /* mlx5_tx_mpw.c */ MLX5_TXOFF_PRE_DECL(none_mpw); MLX5_TXOFF_PRE_DECL(mci_mpw); MLX5_TXOFF_PRE_DECL(mc_mpw); +#ifndef MLX5_MINIMAL_TX MLX5_TXOFF_PRE_DECL(i_mpw); +#endif static __rte_always_inline struct mlx5_uar_data * mlx5_tx_bfreg(struct mlx5_txq_data *txq) diff --git a/drivers/net/mlx5/mlx5_tx_empw.c b/drivers/net/mlx5/mlx5_tx_empw.c index 81c2dc451b14..4cb9965956c5 100644 --- a/drivers/net/mlx5/mlx5_tx_empw.c +++ b/drivers/net/mlx5/mlx5_tx_empw.c @@ -9,6 +9,14 @@ MLX5_TXOFF_DECL(full_empw, MLX5_TXOFF_CONFIG_FULL | MLX5_TXOFF_CONFIG_EMPW) +#ifdef MLX5_MINIMAL_TX +MLX5_TXOFF_DECL(full_noi_empw, + MLX5_TXOFF_CONFIG_MULTI | MLX5_TXOFF_CONFIG_TSO | + MLX5_TXOFF_CONFIG_SWP | MLX5_TXOFF_CONFIG_CSUM | + MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA | + MLX5_TXOFF_CONFIG_EMPW) +#else + MLX5_TXOFF_DECL(none_empw, MLX5_TXOFF_CONFIG_NONE | MLX5_TXOFF_CONFIG_EMPW) @@ -69,3 +77,5 @@ MLX5_TXOFF_DECL(v_empw, MLX5_TXOFF_DECL(iv_empw, MLX5_TXOFF_CONFIG_INLINE | MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA | MLX5_TXOFF_CONFIG_EMPW) + +#endif /* !MLX5_MINIMAL_TX */ diff --git a/drivers/net/mlx5/mlx5_tx_mpw.c b/drivers/net/mlx5/mlx5_tx_mpw.c index bd7d5d2e533f..15061cde5bb1 100644 --- a/drivers/net/mlx5/mlx5_tx_mpw.c +++ b/drivers/net/mlx5/mlx5_tx_mpw.c @@ -29,6 +29,8 @@ MLX5_TXOFF_DECL(mc_mpw, MLX5_TXOFF_CONFIG_MULTI | MLX5_TXOFF_CONFIG_CSUM | MLX5_TXOFF_CONFIG_EMPW | MLX5_TXOFF_CONFIG_MPW) +#ifndef MLX5_MINIMAL_TX MLX5_TXOFF_DECL(i_mpw, MLX5_TXOFF_CONFIG_INLINE | MLX5_TXOFF_CONFIG_EMPW | MLX5_TXOFF_CONFIG_MPW) +#endif diff --git a/drivers/net/mlx5/mlx5_tx_nompw.c b/drivers/net/mlx5/mlx5_tx_nompw.c index ad23aab5d37b..a4d9ac8c576a 100644 --- a/drivers/net/mlx5/mlx5_tx_nompw.c +++ b/drivers/net/mlx5/mlx5_tx_nompw.c @@ -9,6 +9,13 @@ MLX5_TXOFF_DECL(full, MLX5_TXOFF_CONFIG_FULL) +#ifdef MLX5_MINIMAL_TX +MLX5_TXOFF_DECL(full_noi, + MLX5_TXOFF_CONFIG_MULTI | MLX5_TXOFF_CONFIG_TSO | + MLX5_TXOFF_CONFIG_SWP | MLX5_TXOFF_CONFIG_CSUM | + MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA) +#else + MLX5_TXOFF_DECL(none, MLX5_TXOFF_CONFIG_NONE) @@ -69,3 +76,5 @@ MLX5_TXOFF_DECL(v, MLX5_TXOFF_DECL(iv, MLX5_TXOFF_CONFIG_INLINE | MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA) + +#endif /* !MLX5_MINIMAL_TX */ diff --git a/drivers/net/mlx5/mlx5_tx_txpp.c b/drivers/net/mlx5/mlx5_tx_txpp.c index 4d2a4c65f752..3e48a2bbe23c 100644 --- a/drivers/net/mlx5/mlx5_tx_txpp.c +++ b/drivers/net/mlx5/mlx5_tx_txpp.c @@ -25,6 +25,7 @@ MLX5_TXOFF_DECL(full_ts_noi, MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA | MLX5_TXOFF_CONFIG_TXPP | MLX5_TXOFF_CONFIG_EMPW) +#ifndef MLX5_MINIMAL_TX MLX5_TXOFF_DECL(none_ts, MLX5_TXOFF_CONFIG_NONE | MLX5_TXOFF_CONFIG_TXPP | MLX5_TXOFF_CONFIG_EMPW) @@ -43,3 +44,4 @@ MLX5_TXOFF_DECL(mtiv_ts, MLX5_TXOFF_CONFIG_INLINE | MLX5_TXOFF_CONFIG_VLAN | MLX5_TXOFF_CONFIG_METADATA | MLX5_TXOFF_CONFIG_TXPP | MLX5_TXOFF_CONFIG_EMPW) +#endif /* !MLX5_MINIMAL_TX */ -- 2.53.0
