[dpdk-dev] [PATCH v2 07/11] hash: add new function rte_hash_reset

[Pablo de Lara]

Added reset function to be able to empty the table,
without having to destroy and create it again.

Signed-off-by: Pablo de Lara <pablo.de.lara.guarch at intel.com>
---
 app/test/test_hash.c                 |  3 +--
 app/test/test_hash_perf.c            | 11 +++--------
 lib/librte_hash/rte_cuckoo_hash.c    | 21 +++++++++++++++++++++
 lib/librte_hash/rte_hash.h           | 11 +++++++++--
 lib/librte_hash/rte_hash_version.map |  1 +
 5 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/app/test/test_hash.c b/app/test/test_hash.c
index 52de1bd..b1ca939 100644
--- a/app/test/test_hash.c
+++ b/app/test/test_hash.c
@@ -1156,8 +1156,7 @@ static int test_average_table_utilization(void)
                no_space = 0;

                /* Reset the table */
-               rte_hash_free(handle);
-               rte_hash_create(&ut_params);
+               rte_hash_reset(handle);
        }

        const unsigned average_keys_added = added_keys_until_no_space / 
ITERATIONS;
diff --git a/app/test/test_hash_perf.c b/app/test/test_hash_perf.c
index 469000e..db0c5e8 100644
--- a/app/test/test_hash_perf.c
+++ b/app/test/test_hash_perf.c
@@ -352,14 +352,10 @@ free_table(unsigned table_index)
        rte_hash_free(h[table_index]);
 }

-static int
+static void
 reset_table(unsigned table_index)
 {
-       free_table(table_index);
-       if (create_table(table_index) != 0)
-               return -1;
-
-       return 0;
+       rte_hash_reset(h[table_index]);
 }

 static int
@@ -396,8 +392,7 @@ run_all_tbl_perf_tests(void)
                if (timed_deletes(1, i) < 0)
                        return -1;

-               if (reset_table(i) < 0)
-                       return -1;
+               reset_table(i);

                printf("\n ----- WITH JUST KEYS -----\n\n");

diff --git a/lib/librte_hash/rte_cuckoo_hash.c 
b/lib/librte_hash/rte_cuckoo_hash.c
index f1b6df0..8e5b9a6 100644
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -356,6 +356,27 @@ rte_hash_secondary_hash(const hash_sig_t primary_hash)
        return (primary_hash ^ ((tag + 1) * alt_bits_xor));
 }

+void
+rte_hash_reset(struct rte_hash *h)
+{
+       void *ptr;
+       unsigned i;
+
+       if (h == NULL)
+               return;
+
+       memset(h->buckets, 0, h->num_buckets * sizeof(struct rte_hash_bucket));
+       memset(h->key_store, 0, h->key_entry_size * h->entries);
+
+       /* clear the free ring */
+       while (rte_ring_dequeue(h->free_slots, &ptr) == 0)
+               rte_pause();
+
+       /* Repopulate the free slots ring. Entry zero is reserved for key 
misses */
+       for (i = 1; i < h->entries + 1; i++)
+               rte_ring_sp_enqueue(h->free_slots, (void *)((uintptr_t) i));
+}
+
 /*
  * Try to insert a new entry. If bucket has space, hash value and key index
  * to the key table are copied.
diff --git a/lib/librte_hash/rte_hash.h b/lib/librte_hash/rte_hash.h
index 7f7e75f..fa327c2 100644
--- a/lib/librte_hash/rte_hash.h
+++ b/lib/librte_hash/rte_hash.h
@@ -132,8 +132,15 @@ void
 rte_hash_free(struct rte_hash *h);

 /**
- * Add a key to an existing hash table.
- * This operation is not multi-thread safe
+ * Reset all hash structure, by zeroing all entries
+ * @param h
+ *   Hash table to reset
+ */
+void
+rte_hash_reset(struct rte_hash *h);
+
+/**
+ * Add a key to an existing hash table. This operation is not multi-thread safe
  * and should only be called from one thread.
  *
  * @param h
diff --git a/lib/librte_hash/rte_hash_version.map 
b/lib/librte_hash/rte_hash_version.map
index fd92def..f011054 100644
--- a/lib/librte_hash/rte_hash_version.map
+++ b/lib/librte_hash/rte_hash_version.map
@@ -22,6 +22,7 @@ DPDK_2.1 {
        global:

        rte_hash_lookup_bulk_with_hash;
+       rte_hash_reset;

        local: *;
 } DPDK_2.0;
-- 
2.4.2