Hi Robin,
LGTM, with a few minor notes:
- could you please update release notes?
- see the rest inline
On 10/15/2025 10:53 AM, Robin Jarry wrote:
Currently, for the TRIE algorithm, the tbl8 group is freed even though
the readers might be using the tbl8 group entries. The freed tbl8 group
can be reallocated quickly. As a result, lookup may be performed
incorrectly.
To address that, RCU QSBR is integrated for safe tbl8 group reclamation.
Cc: Vladimir Medvedkin <[email protected]>
Signed-off-by: Robin Jarry <[email protected]>
---
Notes:
v2:
- Fixed typos in docstrings.
- Tests depend on: http://patches.dpdk.org/project/dpdk/list/?series=36356
app/test/test_fib6.c | 214 +++++++++++++++++++++++++++++++++++++++++++
lib/fib/rte_fib6.c | 15 +++
lib/fib/rte_fib6.h | 52 +++++++++++
lib/fib/trie.c | 89 ++++++++++++++++--
lib/fib/trie.h | 8 ++
5 files changed, 371 insertions(+), 7 deletions(-)
<snip>
diff --git a/lib/fib/rte_fib6.c b/lib/fib/rte_fib6.c
index 93a1c7197b26..dffcbdf657e8 100644
--- a/lib/fib/rte_fib6.c
+++ b/lib/fib/rte_fib6.c
@@ -346,3 +346,18 @@ rte_fib6_select_lookup(struct rte_fib6 *fib,
return -EINVAL;
}
}
+
+RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_fib6_rcu_qsbr_add, 25.07)
25.11?
+int
+rte_fib6_rcu_qsbr_add(struct rte_fib6 *fib, struct rte_fib6_rcu_config *cfg)
+{
+ if (fib == NULL || cfg == NULL)
+ return -EINVAL;
+
+ switch (fib->type) {
+ case RTE_FIB6_TRIE:
+ return trie_rcu_qsbr_add(fib->dp, cfg, fib->name);
+ default:
+ return -ENOTSUP;
+ }
+}
<snip>
+int
+trie_rcu_qsbr_add(struct rte_trie_tbl *dp, struct rte_fib6_rcu_config *cfg,
+ const char *name)
+{
+ struct rte_rcu_qsbr_dq_parameters params = {0};
+ char rcu_dq_name[RTE_RCU_QSBR_DQ_NAMESIZE];
+
+ if (dp == NULL || cfg == NULL)
+ return -EINVAL;
+
+ if (dp->v != NULL)
+ return -EEXIST;
+
+ switch (cfg->mode) {
+ case RTE_FIB6_QSBR_MODE_DQ:
+ /* Init QSBR defer queue. */
+ snprintf(rcu_dq_name, sizeof(rcu_dq_name),
+ "FIB_RCU_%s", name);
+ params.name = rcu_dq_name;
+ params.size = cfg->dq_size;
+ if (params.size == 0)
+ params.size = RTE_FIB6_RCU_DQ_RECLAIM_SZ;
+ params.trigger_reclaim_limit = cfg->reclaim_thd;
+ params.max_reclaim_size = cfg->reclaim_max;
+ if (params.max_reclaim_size == 0)
+ params.max_reclaim_size = RTE_FIB6_RCU_DQ_RECLAIM_MAX;
+ params.esize = sizeof(uint64_t);
+ params.free_fn = __rcu_qsbr_free_resource;
+ params.p = dp;
+ params.v = cfg->v;
+ dp->dq = rte_rcu_qsbr_dq_create(¶ms);
+ if (dp->dq == NULL) {
+ FIB_LOG(ERR, "FIB6 defer queue creation failed");
+ return -ENOMEM;
+ }
I think it would be better to add here an explicit break instead of
falling through
+ case RTE_FIB6_QSBR_MODE_SYNC:
+ /* No other things to do. */
+ break;
+ default:
+ return -EINVAL;
+ }
+ dp->rcu_mode = cfg->mode;
+ dp->v = cfg->v;
+
+ return 0;
+}
diff --git a/lib/fib/trie.h b/lib/fib/trie.h
index bcb161702b49..c34cc2c05731 100644
--- a/lib/fib/trie.h
+++ b/lib/fib/trie.h
@@ -38,6 +38,10 @@ struct rte_trie_tbl {
uint64_t *tbl8; /**< tbl8 table. */
uint32_t *tbl8_pool; /**< bitmap containing free tbl8 idxes*/
uint32_t tbl8_pool_pos;
+ /* RCU config. */
+ enum rte_fib6_qsbr_mode rcu_mode; /**< Blocking, defer queue. */
+ struct rte_rcu_qsbr *v; /**< RCU QSBR variable. */
+ struct rte_rcu_qsbr_dq *dq; /**< RCU QSBR defer queue. */
/* tbl24 table. */
alignas(RTE_CACHE_LINE_SIZE) uint64_t tbl24[];
};
@@ -143,4 +147,8 @@ int
trie_modify(struct rte_fib6 *fib, const struct rte_ipv6_addr *ip,
uint8_t depth, uint64_t next_hop, int op);
+int
+trie_rcu_qsbr_add(struct rte_trie_tbl *dp, struct rte_fib6_rcu_config *cfg,
+ const char *name);
+
#endif /* _TRIE_H_ */
--
Regards,
Vladimir
