[ovs-dev] [PATCH v5 07/12] dpif-avx512: Add SMC support to avx512 DPIF

Harry van Haaren harry.van.haaren at intel.com
Thu Dec 3 19:37:42 UTC 2020


From: Cian Ferriter <cian.ferriter at intel.com>

Use dp_netdev_pmd_thread->dp_netdev_pmd_thread_ctx to store whether the
SMC is enabled. Also implement a single patcket version of SMC lookup.

Signed-off-by: Cian Ferriter <cian.ferriter at intel.com>
Co-authored-by: Harry van Haaren <harry.van.haaren at intel.com>
Signed-off-by: Harry van Haaren <harry.van.haaren at intel.com>

---

v5:
- Move increment of SMC_HITS stat to this patch for compilation fixup
- Fixup compile issue on returning 0 instead of NULL for pointer
---
 lib/dpif-netdev-avx512.c         | 19 ++++++++++++++++++-
 lib/dpif-netdev-private-dfc.h    |  8 ++++++++
 lib/dpif-netdev-private-thread.h |  2 ++
 lib/dpif-netdev.c                | 28 ++++++++++++++++++++++++++++
 4 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/lib/dpif-netdev-avx512.c b/lib/dpif-netdev-avx512.c
index 5bf6cf073..f51155d6e 100644
--- a/lib/dpif-netdev-avx512.c
+++ b/lib/dpif-netdev-avx512.c
@@ -83,7 +83,10 @@ dp_netdev_input_outer_avx512(struct dp_netdev_pmd_thread *pmd,
     /* Check if EMC or SMC are enabled */
     struct dfc_cache *cache = &pmd->flow_cache;
     const uint32_t emc_enabled = pmd->ctx.emc_insert_min != 0;
+    bool smc_enable_db = pmd->ctx.smc_enable_db;
+
     uint32_t emc_hits = 0;
+    uint32_t smc_hits = 0;
 
     /* a 1 bit in this mask indidcates a hit, so no DPCLS lookup on the pkt. */
     uint32_t hwol_emc_smc_hitmask = 0;
@@ -113,8 +116,11 @@ dp_netdev_input_outer_avx512(struct dp_netdev_pmd_thread *pmd,
          */
         key->hash = dpif_netdev_packet_get_rss_hash_orig_pkt(packet, &key->mf);
 
+        struct dp_netdev_flow *f = NULL;
+
         if (emc_enabled) {
-            struct dp_netdev_flow *f = emc_lookup(&cache->emc_cache, key);
+            f = emc_lookup(&cache->emc_cache, key);
+
             if (f) {
                 rules[i] = &f->cr;
                 emc_hits++;
@@ -123,6 +129,16 @@ dp_netdev_input_outer_avx512(struct dp_netdev_pmd_thread *pmd,
             }
         };
 
+        if (smc_enable_db && !f) {
+            f = smc_lookup_single(pmd, packet, key);
+            if (f) {
+                rules[i] = &f->cr;
+                smc_hits++;
+                hwol_emc_smc_hitmask |= (1 << i);
+                continue;
+            }
+        }
+
         /* The flow pointer was not found in HWOL/EMC/SMC, so add it to the
          * dpcls input keys array for batch lookup later.
          */
@@ -175,6 +191,7 @@ dp_netdev_input_outer_avx512(struct dp_netdev_pmd_thread *pmd,
     /* At this point we don't return error anymore, so commit stats here. */
     pmd_perf_update_counter(&pmd->perf_stats, PMD_STAT_RECV, batch_size);
     pmd_perf_update_counter(&pmd->perf_stats, PMD_STAT_EXACT_HIT, emc_hits);
+    pmd_perf_update_counter(&pmd->perf_stats, PMD_STAT_SMC_HIT, smc_hits);
     pmd_perf_update_counter(&pmd->perf_stats, PMD_STAT_MASKED_HIT,
                             dpcls_key_idx);
     pmd_perf_update_counter(&pmd->perf_stats, PMD_STAT_MASKED_LOOKUP,
diff --git a/lib/dpif-netdev-private-dfc.h b/lib/dpif-netdev-private-dfc.h
index 8f6a4899e..2cee0a38d 100644
--- a/lib/dpif-netdev-private-dfc.h
+++ b/lib/dpif-netdev-private-dfc.h
@@ -81,6 +81,9 @@ extern "C" {
 #define DEFAULT_EM_FLOW_INSERT_MIN (UINT32_MAX /                     \
                                     DEFAULT_EM_FLOW_INSERT_INV_PROB)
 
+/* Forward declaration for SMC function prototype. */
+struct dp_netdev_pmd_thread;
+
 struct emc_entry {
     struct dp_netdev_flow *flow;
     struct netdev_flow_key key;   /* key.hash used for emc hash value. */
@@ -237,6 +240,11 @@ emc_lookup(struct emc_cache *cache, const struct netdev_flow_key *key)
     return NULL;
 }
 
+struct dp_netdev_flow *
+smc_lookup_single(struct dp_netdev_pmd_thread *pmd,
+                  struct dp_packet *packet,
+                  struct netdev_flow_key *key);
+
 #ifdef  __cplusplus
 }
 #endif
diff --git a/lib/dpif-netdev-private-thread.h b/lib/dpif-netdev-private-thread.h
index 18387b81d..c47fe92dc 100644
--- a/lib/dpif-netdev-private-thread.h
+++ b/lib/dpif-netdev-private-thread.h
@@ -45,6 +45,8 @@ struct dp_netdev_pmd_thread_ctx {
     struct dp_netdev_rxq *last_rxq;
     /* EMC insertion probability context for the current processing cycle. */
     uint32_t emc_insert_min;
+    /* Enable the SMC cache from ovsdb config */
+    bool smc_enable_db;
 };
 
 /* Forward declaration for typedef */
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index e8d47e539..a8e656069 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -5183,6 +5183,8 @@ dpif_netdev_run(struct dpif *dpif)
                     non_pmd->ctx.emc_insert_min = 0;
                 }
 
+                non_pmd->ctx.smc_enable_db = dp->smc_enable_db;
+
                 for (i = 0; i < port->n_rxq; i++) {
 
                     if (!netdev_rxq_enabled(port->rxqs[i].rx)) {
@@ -5454,6 +5456,8 @@ reload:
                 pmd->ctx.emc_insert_min = 0;
             }
 
+            pmd->ctx.smc_enable_db = pmd->dp->smc_enable_db;
+
             process_packets =
                 dp_netdev_process_rxq_port(pmd, poll_list[i].rxq,
                                            poll_list[i].port_no);
@@ -6542,6 +6546,30 @@ smc_lookup_batch(struct dp_netdev_pmd_thread *pmd,
     pmd_perf_update_counter(&pmd->perf_stats, PMD_STAT_SMC_HIT, n_smc_hit);
 }
 
+struct dp_netdev_flow *
+smc_lookup_single(struct dp_netdev_pmd_thread *pmd,
+                  struct dp_packet *packet,
+                  struct netdev_flow_key *key)
+{
+    const struct cmap_node *flow_node = smc_entry_get(pmd, key->hash);
+
+    if (OVS_LIKELY(flow_node != NULL)) {
+        struct dp_netdev_flow *flow = NULL;
+
+        CMAP_NODE_FOR_EACH (flow, node, flow_node) {
+            /* Since we dont have per-port megaflow to check the port
+             * number, we need to  verify that the input ports match. */
+            if (OVS_LIKELY(dpcls_rule_matches_key(&flow->cr, key) &&
+                flow->flow.in_port.odp_port == packet->md.in_port.odp_port)) {
+
+                return (void *) flow;
+            }
+        }
+    }
+
+    return NULL;
+}
+
 /* Try to process all ('cnt') the 'packets' using only the datapath flow cache
  * 'pmd->flow_cache'. If a flow is not found for a packet 'packets[i]', the
  * miniflow is copied into 'keys' and the packet pointer is moved at the
-- 
2.25.1



More information about the dev mailing list