netdev - [net-next 05/14] net/mlx5: DR, Allocate ste_arr on stack instead of dynamically

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Message-Id: <20221024135734.69673-6-saeed@kernel.org>
Date:   Mon, 24 Oct 2022 14:57:25 +0100
From:   Saeed Mahameed <saeed@...nel.org>
To:     "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Eric Dumazet <edumazet@...gle.com>
Cc:     Saeed Mahameed <saeedm@...dia.com>, netdev@...r.kernel.org,
        Tariq Toukan <tariqt@...dia.com>,
        Yevgeny Kliteynik <kliteyn@...dia.com>,
        Alex Vesker <valex@...dia.com>
Subject: [net-next 05/14] net/mlx5: DR, Allocate ste_arr on stack instead of dynamically

From: Yevgeny Kliteynik <kliteyn@...dia.com>

While creting rule, ste_arr is a short array that is allocated in
the beginning of the function and freed at the end.
To avoid memory allocation "hiccups" that sometimes take up to 10ms,
allocate it on stack.

Signed-off-by: Yevgeny Kliteynik <kliteyn@...dia.com>
Reviewed-by: Alex Vesker <valex@...dia.com>
Signed-off-by: Saeed Mahameed <saeedm@...dia.com>
---
 .../net/ethernet/mellanox/mlx5/core/steering/dr_rule.c   | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_rule.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_rule.c
index ddfaf7891188..cd90f0a02434 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_rule.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_rule.c
@@ -1089,6 +1089,7 @@ dr_rule_create_rule_nic(struct mlx5dr_rule *rule,
 			size_t num_actions,
 			struct mlx5dr_action *actions[])
 {
+	u8 hw_ste_arr[DR_RULE_MAX_STE_CHAIN * DR_STE_SIZE] = {};
 	struct mlx5dr_ste_send_info *ste_info, *tmp_ste_info;
 	struct mlx5dr_matcher *matcher = rule->matcher;
 	struct mlx5dr_domain *dmn = matcher->tbl->dmn;
@@ -1098,7 +1099,6 @@ dr_rule_create_rule_nic(struct mlx5dr_rule *rule,
 	struct mlx5dr_ste_htbl *cur_htbl;
 	struct mlx5dr_ste *ste = NULL;
 	LIST_HEAD(send_ste_list);
-	u8 *hw_ste_arr = NULL;
 	u32 new_hw_ste_arr_sz;
 	int ret, i;
 
@@ -1109,10 +1109,6 @@ dr_rule_create_rule_nic(struct mlx5dr_rule *rule,
 			 rule->flow_source))
 		return 0;
 
-	hw_ste_arr = kzalloc(DR_RULE_MAX_STE_CHAIN * DR_STE_SIZE, GFP_KERNEL);
-	if (!hw_ste_arr)
-		return -ENOMEM;
-
 	mlx5dr_domain_nic_lock(nic_dmn);
 
 	ret = mlx5dr_matcher_add_to_tbl_nic(dmn, nic_matcher);
@@ -1187,8 +1183,6 @@ dr_rule_create_rule_nic(struct mlx5dr_rule *rule,
 
 	mlx5dr_domain_nic_unlock(nic_dmn);
 
-	kfree(hw_ste_arr);
-
 	return 0;
 
 free_rule:
@@ -1204,7 +1198,6 @@ dr_rule_create_rule_nic(struct mlx5dr_rule *rule,
 
 free_hw_ste:
 	mlx5dr_domain_nic_unlock(nic_dmn);
-	kfree(hw_ste_arr);
 	return ret;
 }
 
-- 
2.37.3