[PATCH v6 10/27] net/i40e: avoid rte malloc in RSS RETA operations

[Anatoly Burakov]

Currently, when updating or querying RSS redirection table (RETA), we
are using rte_zmalloc followed by an immediate rte_free. This memory does
not need to be stored in hugepage memory and the maximum LUT size is 512
bytes, so replace it with stack-based allocation.

Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
---
 drivers/net/intel/i40e/i40e_ethdev.c | 25 ++++---------------------
 1 file changed, 4 insertions(+), 21 deletions(-)

diff --git a/drivers/net/intel/i40e/i40e_ethdev.c 
b/drivers/net/intel/i40e/i40e_ethdev.c
index d3404d7720..d1f8e12689 100644
--- a/drivers/net/intel/i40e/i40e_ethdev.c
+++ b/drivers/net/intel/i40e/i40e_ethdev.c
@@ -4619,7 +4619,7 @@ i40e_dev_rss_reta_update(struct rte_eth_dev *dev,
        struct i40e_pf *pf = I40E_DEV_PRIVATE_TO_PF(dev->data->dev_private);
        uint16_t i, lut_size = pf->hash_lut_size;
        uint16_t idx, shift;
-       uint8_t *lut;
+       uint8_t lut[RTE_ETH_RSS_RETA_SIZE_512] = {0};
        int ret;
 
        if (reta_size != lut_size ||
@@ -4630,14 +4630,9 @@ i40e_dev_rss_reta_update(struct rte_eth_dev *dev,
                return -EINVAL;
        }
 
-       lut = rte_zmalloc("i40e_rss_lut", reta_size, 0);
-       if (!lut) {
-               PMD_DRV_LOG(ERR, "No memory can be allocated");
-               return -ENOMEM;
-       }
        ret = i40e_get_rss_lut(pf->main_vsi, lut, reta_size);
        if (ret)
-               goto out;
+               return ret;
        for (i = 0; i < reta_size; i++) {
                idx = i / RTE_ETH_RETA_GROUP_SIZE;
                shift = i % RTE_ETH_RETA_GROUP_SIZE;
@@ -4648,9 +4643,6 @@ i40e_dev_rss_reta_update(struct rte_eth_dev *dev,
 
        pf->adapter->rss_reta_updated = 1;
 
-out:
-       rte_free(lut);
-
        return ret;
 }
 
@@ -4662,7 +4654,7 @@ i40e_dev_rss_reta_query(struct rte_eth_dev *dev,
        struct i40e_pf *pf = I40E_DEV_PRIVATE_TO_PF(dev->data->dev_private);
        uint16_t i, lut_size = pf->hash_lut_size;
        uint16_t idx, shift;
-       uint8_t *lut;
+       uint8_t lut[RTE_ETH_RSS_RETA_SIZE_512] = {0};
        int ret;
 
        if (reta_size != lut_size ||
@@ -4673,15 +4665,9 @@ i40e_dev_rss_reta_query(struct rte_eth_dev *dev,
                return -EINVAL;
        }
 
-       lut = rte_zmalloc("i40e_rss_lut", reta_size, 0);
-       if (!lut) {
-               PMD_DRV_LOG(ERR, "No memory can be allocated");
-               return -ENOMEM;
-       }
-
        ret = i40e_get_rss_lut(pf->main_vsi, lut, reta_size);
        if (ret)
-               goto out;
+               return ret;
        for (i = 0; i < reta_size; i++) {
                idx = i / RTE_ETH_RETA_GROUP_SIZE;
                shift = i % RTE_ETH_RETA_GROUP_SIZE;
@@ -4689,9 +4675,6 @@ i40e_dev_rss_reta_query(struct rte_eth_dev *dev,
                        reta_conf[idx].reta[shift] = lut[i];
        }
 
-out:
-       rte_free(lut);
-
        return ret;
 }
 
-- 
2.47.3