[dpdk-dev] [PATCH v9 1/5] i40e: use constant as the default hash keys

[Helin Zhang]

Calculating the default RSS hash keys at run time is not needed
at all, and may have race conditions. The alternative is to use
array of random values which were generated manually as the
default hash keys.

Signed-off-by: Helin Zhang <helin.zhang at intel.com>
---
 lib/librte_pmd_i40e/i40e_ethdev.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/lib/librte_pmd_i40e/i40e_ethdev.c b/lib/librte_pmd_i40e/i40e_ethdev.c
index b47a3d2..48bc34d 100644
--- a/lib/librte_pmd_i40e/i40e_ethdev.c
+++ b/lib/librte_pmd_i40e/i40e_ethdev.c
@@ -73,7 +73,7 @@
 /* Maximun number of VSI */
 #define I40E_MAX_NUM_VSIS          (384UL)
 
-/* Default queue interrupt throttling time in microseconds*/
+/* Default queue interrupt throttling time in microseconds */
 #define I40E_ITR_INDEX_DEFAULT          0
 #define I40E_QUEUE_ITR_INTERVAL_DEFAULT 32 /* 32 us */
 #define I40E_QUEUE_ITR_INTERVAL_MAX     8160 /* 8160 us */
@@ -200,9 +200,6 @@ static int i40e_dev_filter_ctrl(struct rte_eth_dev *dev,
 				void *arg);
 static void i40e_configure_registers(struct i40e_hw *hw);
 
-/* Default hash key buffer for RSS */
-static uint32_t rss_key_default[I40E_PFQF_HKEY_MAX_INDEX + 1];
-
 static struct rte_pci_id pci_id_i40e_map[] = {
 #define RTE_PCI_DEV_ID_DECL_I40E(vend, dev) {RTE_PCI_DEVICE(vend, dev)},
 #include "rte_pci_dev_ids.h"
@@ -5039,9 +5036,12 @@ i40e_pf_config_rss(struct i40e_pf *pf)
 	}
 	if (rss_conf.rss_key == NULL || rss_conf.rss_key_len <
 		(I40E_PFQF_HKEY_MAX_INDEX + 1) * sizeof(uint32_t)) {
-		/* Calculate the default hash key */
-		for (i = 0; i <= I40E_PFQF_HKEY_MAX_INDEX; i++)
-			rss_key_default[i] = (uint32_t)rte_rand();
+		/* Random default keys */
+		static uint32_t rss_key_default[] = {0x6b793944,
+			0x23504cb5, 0x5bea75b6, 0x309f4f12, 0x3dc0a2b8,
+			0x024ddcdf, 0x339b8ca0, 0x4c4af64a, 0x34fac605,
+			0x55d85839, 0x3a58997d, 0x2ec938e1, 0x66031581};
+
 		rss_conf.rss_key = (uint8_t *)rss_key_default;
 		rss_conf.rss_key_len = (I40E_PFQF_HKEY_MAX_INDEX + 1) *
 							sizeof(uint32_t);
-- 
1.8.1.4