This patch adds a comment for RTE_HASH_BUCKET_ENTRIES
explaining why a particular value was chosen.
Signed-off-by: Vladimir Medvedkin <vladimir.medved...@intel.com>
---
lib/hash/rte_cuckoo_hash.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/lib/hash/rte_cuckoo_hash.h b/lib/hash/rte_cuckoo_hash.h
index 85be49d3bb..eb2644f74b 100644
--- a/lib/hash/rte_cuckoo_hash.h
+++ b/lib/hash/rte_cuckoo_hash.h
@@ -101,7 +101,13 @@ const rte_hash_cmp_eq_t cmp_jump_table[NUM_KEY_CMP_CASES]
= {
#endif
-/** Number of items per bucket. */
+/**
+ * Number of items per bucket.
+ * 8 is a tradeoff between performance and memory consumption.
+ * When it is equal to 8, multiple 'struct rte_hash_bucket' can be fit
+ * on a single cache line (64 or 128 bytes long) without any gaps
+ * in memory between them due to alignment.
+ */
#define RTE_HASH_BUCKET_ENTRIES 8
#if !RTE_IS_POWER_OF_2(RTE_HASH_BUCKET_ENTRIES)
--
2.25.1
