> -----Original Message----- > From: dev [mailto:dev-boun...@openvswitch.org] On Behalf Of Daniele Di > Proietto > Sent: Thursday, April 23, 2015 7:40 PM > To: dev@openvswitch.org > Subject: [ovs-dev] [PATCH 7/7] dpif-netdev: Share emc and fast path output > batches. > > Until now the exact match cache processing was able to handle only four > megaflow. The rest of the packets was passed to the megaflow > classifier. > > The limit was arbitraly set to four also because the algorithm used to > group packets in output batches didn't perform well with a lot of > megaflows. > > After changing the algorithm and after some performance testing it seems > much better just share the same output batches between the exact match > cache and the megaflow classifier. > > Signed-off-by: Daniele Di Proietto <diproiet...@vmware.com> > --- > lib/dpif-netdev.c | 71 +++++++++++++++++++++++------------------------------ > -- > 1 file changed, 29 insertions(+), 42 deletions(-) > > diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c > index 333f5a4..0c3f9e7 100644 > --- a/lib/dpif-netdev.c > +++ b/lib/dpif-netdev.c > @@ -3063,7 +3063,6 @@ packet_batch_init(struct packet_batch *batch, struct > dp_netdev_flow *flow) > static inline void > packet_batch_execute(struct packet_batch *batch, > struct dp_netdev_pmd_thread *pmd, > - enum dp_stat_type hit_type, > long long now) > { > struct dp_netdev_actions *actions; > @@ -3077,15 +3076,12 @@ packet_batch_execute(struct packet_batch *batch, > > dp_netdev_execute_actions(pmd, batch->packets, batch->packet_count, > true, > actions->actions, actions->size); > - > - dp_netdev_count_packet(pmd, hit_type, batch->packet_count); > } > > static inline bool > dp_netdev_queue_batches(struct dp_packet *pkt, > struct dp_netdev_flow *flow, const struct miniflow > *mf, > - struct packet_batch *batches, size_t *n_batches, > - size_t max_batches) > + struct packet_batch *batches, size_t *n_batches) > { > struct packet_batch *batch; > > @@ -3100,10 +3096,6 @@ dp_netdev_queue_batches(struct dp_packet *pkt, > return true; > } > > - if (OVS_UNLIKELY(*n_batches >= max_batches)) { > - return false; > - } > - > batch = &batches[(*n_batches)++]; > packet_batch_init(batch, flow); > packet_batch_update(batch, pkt, mf); > @@ -3119,24 +3111,22 @@ dp_packet_swap(struct dp_packet **a, struct dp_packet > **b) > } > > /* Try to process all ('cnt') the 'packets' using only the exact match cache > - * 'flow_cache'. If a flow is not found for a packet 'packets[i]', or if > there > - * is no matching batch for a packet's flow, the miniflow is copied into > 'keys' > - * and the packet pointer is moved at the beginning of the 'packets' array. > + * '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 > + * beginning of the 'packets' array. > * > * The function returns the number of packets that needs to be processed in > the > * 'packets' array (they have been moved to the beginning of the vector). > */ > static inline size_t > emc_processing(struct dp_netdev_pmd_thread *pmd, struct dp_packet **packets, > - size_t cnt, struct netdev_flow_key *keys, long long now) > + size_t cnt, struct netdev_flow_key *keys, > + struct packet_batch batches[], size_t *n_batches) > { > - struct netdev_flow_key key; > - struct packet_batch batches[4]; > struct emc_cache *flow_cache = &pmd->flow_cache; > - size_t n_batches, i; > - size_t notfound_cnt = 0; > + struct netdev_flow_key key; > + size_t i, notfound_cnt = 0; > > - n_batches = 0; > miniflow_initialize(&key.mf, key.buf); > for (i = 0; i < cnt; i++) { > struct dp_netdev_flow *flow; > @@ -3152,8 +3142,7 @@ emc_processing(struct dp_netdev_pmd_thread *pmd, struct > dp_packet **packets, > > flow = emc_lookup(flow_cache, &key); > if (OVS_UNLIKELY(!dp_netdev_queue_batches(packets[i], flow, &key.mf, > - batches, &n_batches, > - ARRAY_SIZE(batches)))) { > + batches, n_batches))) { > if (i != notfound_cnt) { > dp_packet_swap(&packets[i], &packets[notfound_cnt]); > } > @@ -3162,9 +3151,7 @@ emc_processing(struct dp_netdev_pmd_thread *pmd, struct > dp_packet **packets, > } > } > > - for (i = 0; i < n_batches; i++) { > - packet_batch_execute(&batches[i], pmd, DP_STAT_EXACT_HIT, now); > - } > + dp_netdev_count_packet(pmd, DP_STAT_EXACT_HIT, cnt - notfound_cnt); > > return notfound_cnt; > } > @@ -3172,7 +3159,8 @@ emc_processing(struct dp_netdev_pmd_thread *pmd, struct > dp_packet **packets, > static inline void > fast_path_processing(struct dp_netdev_pmd_thread *pmd, > struct dp_packet **packets, size_t cnt, > - struct netdev_flow_key *keys, long long now) > + struct netdev_flow_key *keys, > + struct packet_batch batches[], size_t *n_batches) > { > #if !defined(__CHECKER__) && !defined(_WIN32) > const size_t PKT_ARRAY_SIZE = cnt; > @@ -3180,12 +3168,12 @@ fast_path_processing(struct dp_netdev_pmd_thread > *pmd, > /* Sparse or MSVC doesn't like variable length array. */ > enum { PKT_ARRAY_SIZE = NETDEV_MAX_RX_BATCH }; > #endif > - struct packet_batch batches[PKT_ARRAY_SIZE]; > struct dpcls_rule *rules[PKT_ARRAY_SIZE]; > struct dp_netdev *dp = pmd->dp; > struct emc_cache *flow_cache = &pmd->flow_cache; > - size_t n_batches, i; > + int miss_cnt = 0, lost_cnt = 0; > bool any_miss; > + size_t i; > > for (i = 0; i < cnt; i++) { > /* Key length is needed in all the cases, hash computed on demand. > */ > @@ -3195,7 +3183,6 @@ fast_path_processing(struct dp_netdev_pmd_thread *pmd, > if (OVS_UNLIKELY(any_miss) && !fat_rwlock_tryrdlock(&dp->upcall_rwlock)) > { > uint64_t actions_stub[512 / 8], slow_stub[512 / 8]; > struct ofpbuf actions, put_actions; > - int miss_cnt = 0, lost_cnt = 0; > ovs_u128 ufid; > > ofpbuf_use_stub(&actions, actions_stub, sizeof actions_stub); > @@ -3267,23 +3254,17 @@ fast_path_processing(struct dp_netdev_pmd_thread > *pmd, > ofpbuf_uninit(&actions); > ofpbuf_uninit(&put_actions); > fat_rwlock_unlock(&dp->upcall_rwlock); > - dp_netdev_count_packet(pmd, DP_STAT_MISS, miss_cnt); > dp_netdev_count_packet(pmd, DP_STAT_LOST, lost_cnt); > } else if (OVS_UNLIKELY(any_miss)) { > - int dropped_cnt = 0; > - > for (i = 0; i < cnt; i++) { > if (OVS_UNLIKELY(!rules[i])) { > dp_packet_delete(packets[i]); > - dropped_cnt++; > + lost_cnt++; > + miss_cnt++; > } > } > - > - dp_netdev_count_packet(pmd, DP_STAT_MISS, dropped_cnt); > - dp_netdev_count_packet(pmd, DP_STAT_LOST, dropped_cnt); > } > > - n_batches = 0; > for (i = 0; i < cnt; i++) { > struct dp_packet *packet = packets[i]; > struct dp_netdev_flow *flow; > @@ -3296,12 +3277,12 @@ fast_path_processing(struct dp_netdev_pmd_thread > *pmd, > > emc_insert(flow_cache, &keys[i], flow); > dp_netdev_queue_batches(packet, flow, &keys[i].mf, batches, > - &n_batches, ARRAY_SIZE(batches)); > + n_batches); > } > > - for (i = 0; i < n_batches; i++) { > - packet_batch_execute(&batches[i], pmd, DP_STAT_MASKED_HIT, now); > - } > + dp_netdev_count_packet(pmd, DP_STAT_MASKED_HIT, cnt - miss_cnt); > + dp_netdev_count_packet(pmd, DP_STAT_MISS, miss_cnt); > + dp_netdev_count_packet(pmd, DP_STAT_LOST, lost_cnt); > } > > static void > @@ -3315,12 +3296,18 @@ dp_netdev_input(struct dp_netdev_pmd_thread *pmd, > enum { PKT_ARRAY_SIZE = NETDEV_MAX_RX_BATCH }; > #endif > struct netdev_flow_key keys[PKT_ARRAY_SIZE]; > + struct packet_batch batches[PKT_ARRAY_SIZE]; > long long now = time_msec(); > - size_t newcnt; > + size_t newcnt, n_batches, i; > > - newcnt = emc_processing(pmd, packets, cnt, keys, now); > + n_batches = 0; > + newcnt = emc_processing(pmd, packets, cnt, keys, batches, &n_batches); > if (OVS_UNLIKELY(newcnt)) { > - fast_path_processing(pmd, packets, newcnt, keys, now); > + fast_path_processing(pmd, packets, newcnt, keys, batches, > &n_batches); > + } > + > + for (i = 0; i < n_batches; i++) { > + packet_batch_execute(&batches[i], pmd, now); > } > }
By moving the packet_batch_execute() from emc_processing() and combining here, you are holding up executing the packets that hit in the EMC - potentially by a number of upcalls. On the other hand, you could argue you are getting to the upcalls faster :-) I'm not sure how significant it would be in reality, but just said I'd mention so you could consider. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
