This is a patch to a problem that I have faced (described in the thread) and
this works for me.
1) Since the data_size_shl was getting its value from the key_size, the
table data entries were being corrupted when the calculation to shift the
number of bits was being made based on the key_size (according to the document
the key_size and entry_size are independently configurable) - With this fix, we
get the MSB that is set in entry_size (also removes the constraint of this
having to be a power of 2 - not entirely sure if this was the reason the
constraint was kept though)
2) The document does not say that the entry_size needs to be a power of 2
and this was failing silently when I was trying to bring my application up.
diff --git a/DPDK/lib/librte_table/rte_table_hash_lru.c
b/DPDK/lib/librte_table/rte_table_hash_lru.c
index d1a4984..4ec9aa4 100644
--- a/DPDK/lib/librte_table/rte_table_hash_lru.c
+++ b/DPDK/lib/librte_table/rte_table_hash_lru.c
@@ -153,8 +153,10 @@ rte_table_hash_lru_create(void *params, int socket_id,
uint32_t entry_size)
uint32_t i;
/* Check input parameters */
- if ((check_params_create(p) != 0) ||
- (!rte_is_power_of_2(entry_size)) ||
+ // Commenting out the power of 2 check on the entry_size since the
+ // Programmers Guide does not call this out and we are going to handle
+ // the data_size_shl of the table later on (Line 197)
+ if ((check_params_create(p) != 0) ||
((sizeof(struct rte_table_hash) % CACHE_LINE_SIZE) != 0) ||
(sizeof(struct bucket) != (CACHE_LINE_SIZE / 2))) {
return NULL;
@@ -192,7 +194,7 @@ rte_table_hash_lru_create(void *params, int socket_id,
uint32_t entry_size)
/* Internal */
t->bucket_mask = t->n_buckets - 1;
t->key_size_shl = __builtin_ctzl(p->key_size);
- t->data_size_shl = __builtin_ctzl(p->key_size);
+ t->data_size_shl = 32 - (__builtin_clz(entry_size));
/* Tables */
table_meta_offset = 0;
-----Original Message-----
From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Saha, Avik (AWS)
Sent: Wednesday, September 24, 2014 4:12 PM
To: dev at dpdk.org
Subject: [dpdk-dev] Strange behaviour with LRU table
1) All the calls to add entries succeeds
2) The key look up works as expected.
3) The value (entry_data) that is returned is incorrect for every other
entry - 1st entry data on .f_action_hit is wrong, 2nd entry_data on
.f_action_hit is correct and so on.
I have initialized my LRU as follows:
struct rte_pipeline_table_params table_params = {
.ops = &rte_table_hash_lru_dosig_ops,
.arg_create = &rule_tbl_params,
.f_action_hit = rw_pipeline_stage_2_cache_hit,
.f_action_miss = rw_pipeline_stage_2_cache_miss,
.arg_ah = (void *)lcore_params,
.action_data_size = 16,
};
Is there something obvious I am missing - from first look it seems to be a
problem with cache lines but I really am not sure.
Avik
