Hi Cian, Thank you for your feedback and the interesting measurement results.
As first I was a bit surprised that the gain is smaller in your P2P test case. I guess that is because your traffic passes the datapath (and hence EMC) only once, while in our PVP test with VXLAN each packet causes three passes and EMC lookups, so the effective number of occupied EMC entries is three times as high. Could you test your scenario with significantly more flows to confirm the larger gain with growing number of flows? I set the DFC size by macro to 1M entries mainly because it gave good acceleration all across the entire range of parallel flows we typically test in our NFVI setup (up to 500K flows). The static memory overhead of a 1M DFC is not very high (8 MB per PMD). From that perspective there seemed little need to offer a knob to tune the size for certain use cases. However, if there are sufficient parallel flows to completely fill the DFC, the 8MB L3 cache footprint per PMD is significant and may limit the performance gain across all PMDs and cause additional L3 cache contention with guest applications (VNFs) running on the compute host. So, the main motivation for making the DFC size configurable (or to disable it completely) might be to limit the L3 cache footprint of a PMD. There might be possibly more effective tools on CPU level (e.g. "cache QoS") to achieve the same effect. I am open for discussions on this topic and would welcome multi-PMD measurements. Regards, Jan > -----Original Message----- > From: Ferriter, Cian [mailto:[email protected]] > Sent: Monday, 11 December, 2017 17:29 > To: Jan Scheurich <[email protected]>; [email protected] > Subject: RE: [PATCH] dpif-netdev: Refactor datapath flow cache > > Hi Jan, > > This is a very interesting patch with compelling results. > > I had a few questions after reading the commit message for this patch: > How did you decide on 1M as the proposed size for the DFC? > Will the size of this DFC be configurable (i.e. map a different number of > hash bits)? > > I was mostly interested in how the performance of the very basic phy2phy > testcase would be affected by this change. > Below are my results from 1-10000 flows, 64B packets, unidirectional with 1 > PMD. One OpenFlow rule is installed for each stream of > traffic being sent: > Flows master DFC+EMC Gain > [Mpps] [Mpps] > ------------------------------ > 1 12.34 13.12 6.3% > 10 7.83 8.19 4.5% > 100 4.71 4.78 1.3% > 1000 3.77 3.83 1.5% > 10000 3.27 3.51 7.1% > > This shows a performance improvement for this testcase also. > > Tested-by: Cian Ferriter <[email protected]> > > Let me know your thoughts on the above questions. > Thanks, > Cian > > > -----Original Message----- > > From: [email protected] [mailto:ovs-dev- > > [email protected]] On Behalf Of Jan Scheurich > > Sent: 20 November 2017 17:33 > > To: [email protected] > > Subject: [ovs-dev] [PATCH] dpif-netdev: Refactor datapath flow cache > > > > So far the netdev datapath uses an 8K EMC to speed up the lookup of > > frequently used flows by comparing the parsed packet headers against the > > miniflow of a cached flow, using 13 bits of the packet RSS hash as index. > > The > > EMC is too small for many applications with 100K or more parallel packet > > flows so that EMC threshing actually degrades performance. > > Furthermore, the size of struct miniflow and the flow copying cost prevents > > us from making it much larger. > > > > At the same time the lookup cost of the megaflow classifier (DPCLS) is > > increasing as the number of frequently hit subtables grows with the > > complexity of pipeline and the number of recirculations. > > > > To close the performance gap for many parallel flows, this patch introduces > > the datapath flow cache (DFC) with 1M entries as lookup stage between EMC > > and DPCLS. It directly maps 20 bits of the RSS hash to a pointer to the > > last hit > > megaflow entry and performs a masked comparison of the packet flow with > > the megaflow key to confirm the hit. This avoids the costly DPCLS lookup > > even for very large number of parallel flows with a small memory overhead. > > > > Due the large size of the DFC and the low risk of DFC thrashing, any DPCLS > > hit > > immediately inserts an entry in the DFC so that subsequent packets get > > speeded up. The DFC, thus, accelerate also short-lived flows. > > > > To further accelerate the lookup of few elephant flows, every DFC hit > > triggers a probabilistic EMC insertion of the flow. As the DFC entry is > > already > > in place the default EMC insertion probability can be reduced to > > 1/1000 to minimize EMC thrashing should there still be many fat flows. > > The inverse EMC insertion probability remains configurable. > > > > The EMC implementation is simplified by removing the possibility to store a > > flow in two slots, as there is no particular reason why two flows should > > systematically collide (the RSS hash is not symmetric). > > The maximum size of the EMC flow key is limited to 256 bytes to reduce the > > memory footprint. This should be sufficient to hold most real life packet > > flow > > keys. Larger flows are not installed in the EMC. > > > > The pmd-stats-show command is enhanced to show both EMC and DFC hits > > separately. > > > > The sweep speed for cleaning up obsolete EMC and DFC flow entries and > > freeing dead megaflow entries is increased. With a typical PMD cycle > > duration of 100us under load and checking one DFC entry per cycle, the DFC > > sweep should normally complete within in 100s. > > > > In PVP performance tests with an L3 pipeline over VXLAN we determined the > > optimal EMC size to be 16K entries to obtain a uniform speedup compared to > > the master branch over the full range of parallel flows. The measurement > > below is for 64 byte packets and the average number of subtable lookups per > > DPCLS hit in this pipeline is 1.0, i.e. the acceleration already starts for > > a single > > busy mask. Tests with many visited subtables should show a strong increase > > of the gain through DFC. > > > > Flows master DFC+EMC Gain > > [Mpps] [Mpps] > > ------------------------------ > > 8 4.45 4.62 3.8% > > 100 4.17 4.47 7.2% > > 1000 3.88 4.34 12.0% > > 2000 3.54 4.17 17.8% > > 5000 3.01 3.82 27.0% > > 10000 2.75 3.63 31.9% > > 20000 2.64 3.50 32.8% > > 50000 2.60 3.33 28.1% > > 100000 2.59 3.23 24.7% > > 500000 2.59 3.16 21.9% > > > > > > Signed-off-by: Jan Scheurich <[email protected]> > > --- > > lib/dpif-netdev.c | 349 ++++++++++++++++++++++++++++++++++++------- > > ----------- > > 1 file changed, 235 insertions(+), 114 deletions(-) > > > > diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c index db78318..efcf2e9 > > 100644 > > --- a/lib/dpif-netdev.c > > +++ b/lib/dpif-netdev.c > > @@ -127,19 +127,19 @@ struct netdev_flow_key { > > uint64_t buf[FLOW_MAX_PACKET_U64S]; }; > > > > -/* Exact match cache for frequently used flows > > +/* Datapath flow cache (DFC) for frequently used flows > > * > > - * The cache uses a 32-bit hash of the packet (which can be the RSS hash) > > to > > - * search its entries for a miniflow that matches exactly the miniflow of > > the > > - * packet. It stores the 'dpcls_rule' (rule) that matches the miniflow. > > + * The cache uses the 32-bit hash of the packet (which can be the RSS > > + hash) to > > + * directly look up a pointer to the matching megaflow. To check for a > > + match > > + * the packet's flow key is compared against the key and mask of the > > megaflow. > > * > > - * A cache entry holds a reference to its 'dp_netdev_flow'. > > - * > > - * A miniflow with a given hash can be in one of EM_FLOW_HASH_SEGS > > different > > - * entries. The 32-bit hash is split into EM_FLOW_HASH_SEGS values (each > > of > > - * them is EM_FLOW_HASH_SHIFT bits wide and the remainder is thrown > > away). Each > > - * value is the index of a cache entry where the miniflow could be. > > + * For even faster lookup, the most frequently used packet flows are > > + also > > + * inserted into a small exact match cache (EMC). The EMC uses a part > > + of the > > + * packet hash to look up a miniflow that matches exactly the miniflow > > + of the > > + * packet. The matching EMC also returns a reference to the megaflow. > > * > > + * Flows are promoted from the DFC to the EMC through probabilistic > > + insertion > > + * after successful DFC lookup with minor probability to favor elephant > > flows. > > * > > * Thread-safety > > * ============= > > @@ -148,33 +148,38 @@ struct netdev_flow_key { > > * If dp_netdev_input is not called from a pmd thread, a mutex is used. > > */ > > > > -#define EM_FLOW_HASH_SHIFT 13 > > -#define EM_FLOW_HASH_ENTRIES (1u << EM_FLOW_HASH_SHIFT) - > > #define EM_FLOW_HASH_MASK (EM_FLOW_HASH_ENTRIES - 1) -#define > > EM_FLOW_HASH_SEGS 2 > > +#define DFC_MASK_LEN 20 > > +#define DFC_ENTRIES (1u << DFC_MASK_LEN) #define DFC_MASK > > (DFC_ENTRIES > > +- 1) #define EMC_MASK_LEN 14 #define EMC_ENTRIES (1u << > > EMC_MASK_LEN) > > +#define EMC_MASK (EMC_ENTRIES - 1) > > > > /* Default EMC insert probability is 1 / > > DEFAULT_EM_FLOW_INSERT_INV_PROB */ -#define > > DEFAULT_EM_FLOW_INSERT_INV_PROB 100 > > +#define DEFAULT_EM_FLOW_INSERT_INV_PROB 1000 > > #define DEFAULT_EM_FLOW_INSERT_MIN (UINT32_MAX / \ > > DEFAULT_EM_FLOW_INSERT_INV_PROB) > > > > struct emc_entry { > > struct dp_netdev_flow *flow; > > - struct netdev_flow_key key; /* key.hash used for emc hash value. */ > > + char key[248]; /* Holds struct netdev_flow_key of limited size. */ > > }; > > > > struct emc_cache { > > - struct emc_entry entries[EM_FLOW_HASH_ENTRIES]; > > - int sweep_idx; /* For emc_cache_slow_sweep(). */ > > + struct emc_entry entries[EMC_ENTRIES]; > > + int sweep_idx; > > +}; > > + > > +struct dfc_entry { > > + struct dp_netdev_flow *flow; > > +}; > > + > > +struct dfc_cache { > > + struct emc_cache emc_cache; > > + struct dfc_entry entries[DFC_ENTRIES]; > > + int sweep_idx; > > }; > > > > -/* Iterate in the exact match cache through every entry that might contain > > a > > - * miniflow with hash 'HASH'. */ > > -#define EMC_FOR_EACH_POS_WITH_HASH(EMC, CURRENT_ENTRY, HASH) > > \ > > - for (uint32_t i__ = 0, srch_hash__ = (HASH); > > \ > > - (CURRENT_ENTRY) = &(EMC)->entries[srch_hash__ & > > EM_FLOW_HASH_MASK], \ > > - i__ < EM_FLOW_HASH_SEGS; > > \ > > - i__++, srch_hash__ >>= EM_FLOW_HASH_SHIFT) > > > > /* Simple non-wildcarding single-priority classifier. */ > > > > @@ -214,6 +219,8 @@ static bool dpcls_lookup(struct dpcls *cls, > > const struct netdev_flow_key keys[], > > struct dpcls_rule **rules, size_t cnt, > > int *num_lookups_p); > > +static bool dpcls_rule_matches_key(const struct dpcls_rule *rule, > > + const struct netdev_flow_key > > +*target); > > > > /* Set of supported meter flags */ > > #define DP_SUPPORTED_METER_FLAGS_MASK \ @@ -332,6 +339,7 @@ > > static struct dp_netdev_port *dp_netdev_lookup_port(const struct > > dp_netdev *dp, > > > > enum dp_stat_type { > > DP_STAT_EXACT_HIT, /* Packets that had an exact match (emc). > > */ > > + DP_STAT_DFC_HIT, /* Packets that had a flow cache hit > > (dfc). */ > > DP_STAT_MASKED_HIT, /* Packets that matched in the flow table. > > */ > > DP_STAT_MISS, /* Packets that did not match. */ > > DP_STAT_LOST, /* Packets not passed up to the client. */ > > @@ -565,7 +573,7 @@ struct dp_netdev_pmd_thread { > > * NON_PMD_CORE_ID can be accessed by multiple threads, and thusly > > * need to be protected by 'non_pmd_mutex'. Every other instance > > * will only be accessed by its own pmd thread. */ > > - OVS_ALIGNED_VAR(CACHE_LINE_SIZE) struct emc_cache flow_cache; > > + OVS_ALIGNED_VAR(CACHE_LINE_SIZE) struct dfc_cache flow_cache; > > struct ovs_refcount ref_cnt; /* Every reference must be > > refcount'ed. */ > > > > /* Queue id used by this pmd thread to send packets on all netdevs if > > @@ > > -744,46 +752,59 @@ dpif_netdev_xps_revalidate_pmd(const struct > > dp_netdev_pmd_thread *pmd, static int > > dpif_netdev_xps_get_tx_qid(const struct dp_netdev_pmd_thread *pmd, > > struct tx_port *tx, long long now); > > > > -static inline bool emc_entry_alive(struct emc_entry *ce); > > +static inline bool dfc_entry_alive(struct dfc_entry *ce); > > static void emc_clear_entry(struct emc_entry *ce); > > +static void dfc_clear_entry(struct dfc_entry *ce); > > > > static void dp_netdev_request_reconfigure(struct dp_netdev *dp); > > > > static void > > -emc_cache_init(struct emc_cache *flow_cache) > > +emc_cache_init(struct emc_cache *emc) > > { > > int i; > > > > - flow_cache->sweep_idx = 0; > > + for (i = 0; i < ARRAY_SIZE(emc->entries); i++) { > > + emc->entries[i].flow = NULL; > > + struct netdev_flow_key *key = > > + (struct netdev_flow_key *) emc->entries[i].key; > > + key->hash = 0; > > + key->len = sizeof(struct miniflow); > > + flowmap_init(&key->mf.map); > > + } > > + emc->sweep_idx = 0; > > +} > > + > > +static void > > +dfc_cache_init(struct dfc_cache *flow_cache) { > > + int i; > > + > > + emc_cache_init(&flow_cache->emc_cache); > > for (i = 0; i < ARRAY_SIZE(flow_cache->entries); i++) { > > flow_cache->entries[i].flow = NULL; > > - flow_cache->entries[i].key.hash = 0; > > - flow_cache->entries[i].key.len = sizeof(struct miniflow); > > - flowmap_init(&flow_cache->entries[i].key.mf.map); > > } > > + flow_cache->sweep_idx = 0; > > } > > > > static void > > -emc_cache_uninit(struct emc_cache *flow_cache) > > +emc_cache_uninit(struct emc_cache *emc) > > { > > int i; > > > > - for (i = 0; i < ARRAY_SIZE(flow_cache->entries); i++) { > > - emc_clear_entry(&flow_cache->entries[i]); > > + for (i = 0; i < ARRAY_SIZE(emc->entries); i++) { > > + emc_clear_entry(&emc->entries[i]); > > } > > } > > > > -/* Check and clear dead flow references slowly (one entry at each > > - * invocation). */ > > static void > > -emc_cache_slow_sweep(struct emc_cache *flow_cache) > > +dfc_cache_uninit(struct dfc_cache *flow_cache) > > { > > - struct emc_entry *entry = &flow_cache->entries[flow_cache- > > >sweep_idx]; > > + int i; > > > > - if (!emc_entry_alive(entry)) { > > - emc_clear_entry(entry); > > + for (i = 0; i < ARRAY_SIZE(flow_cache->entries); i++) { > > + dfc_clear_entry(&flow_cache->entries[i]); > > } > > - flow_cache->sweep_idx = (flow_cache->sweep_idx + 1) & > > EM_FLOW_HASH_MASK; > > + emc_cache_uninit(&flow_cache->emc_cache); > > } > > > > /* Returns true if 'dpif' is a netdev or dummy dpif, false otherwise. */ > > @@ - > > 837,8 +858,8 @@ pmd_info_show_stats(struct ds *reply, > > } > > > > /* Sum of all the matched and not matched packets gives the total. */ > > - total_packets = stats[DP_STAT_EXACT_HIT] + > > stats[DP_STAT_MASKED_HIT] > > - + stats[DP_STAT_MISS]; > > + total_packets = stats[DP_STAT_EXACT_HIT] + stats[DP_STAT_DFC_HIT] > > + + stats[DP_STAT_MASKED_HIT] + stats[DP_STAT_MISS]; > > > > for (i = 0; i < PMD_N_CYCLES; i++) { > > if (cycles[i] > pmd->cycles_zero[i]) { @@ -862,10 +883,13 @@ > > pmd_info_show_stats(struct ds *reply, > > ds_put_cstr(reply, ":\n"); > > > > ds_put_format(reply, > > - "\temc hits:%llu\n\tmegaflow hits:%llu\n" > > + "\temc hits:%llu\n\tdfc hits:%llu\n" > > + "\tmegaflow hits:%llu\n" > > "\tavg. subtable lookups per hit:%.2f\n" > > "\tmiss:%llu\n\tlost:%llu\n", > > - stats[DP_STAT_EXACT_HIT], stats[DP_STAT_MASKED_HIT], > > + stats[DP_STAT_EXACT_HIT], > > + stats[DP_STAT_DFC_HIT], > > + stats[DP_STAT_MASKED_HIT], > > stats[DP_STAT_MASKED_HIT] > 0 > > ? > > (1.0*stats[DP_STAT_LOOKUP_HIT])/stats[DP_STAT_MASKED_HIT] > > : 0, > > @@ -1492,6 +1516,8 @@ dpif_netdev_get_stats(const struct dpif *dpif, > > struct dpif_dp_stats *stats) > > stats->n_hit += n; > > atomic_read_relaxed(&pmd->stats.n[DP_STAT_EXACT_HIT], &n); > > stats->n_hit += n; > > + atomic_read_relaxed(&pmd->stats.n[DP_STAT_DFC_HIT], &n); > > + stats->n_hit += n; > > atomic_read_relaxed(&pmd->stats.n[DP_STAT_MISS], &n); > > stats->n_missed += n; > > atomic_read_relaxed(&pmd->stats.n[DP_STAT_LOST], &n); @@ -2111,6 > > +2137,16 @@ netdev_flow_key_hash_in_mask(const struct > > netdev_flow_key *key, > > return hash_finish(hash, (p - miniflow_get_values(&mask->mf)) * 8); } > > > > +/* > > + * Datapath Flow Cache and EMC implementation */ > > + > > +static inline struct emc_entry * > > +emc_entry_get(struct emc_cache *emc, const uint32_t hash) { > > + return &emc->entries[hash & EMC_MASK]; } > > + > > static inline bool > > emc_entry_alive(struct emc_entry *ce) > > { > > @@ -2127,9 +2163,15 @@ emc_clear_entry(struct emc_entry *ce) } > > > > static inline void > > -emc_change_entry(struct emc_entry *ce, struct dp_netdev_flow *flow, > > - const struct netdev_flow_key *key) > > +emc_change_entry(struct emc_entry *ce, const struct netdev_flow_key > > *key, > > + struct dp_netdev_flow *flow) > > { > > + /* We only store small enough flows in the EMC. */ > > + size_t key_size = offsetof(struct netdev_flow_key, mf) + key->len; > > + if (key_size > sizeof(ce->key)) { > > + return; > > + } > > + > > if (ce->flow != flow) { > > if (ce->flow) { > > dp_netdev_flow_unref(ce->flow); @@ -2141,73 +2183,148 @@ > > emc_change_entry(struct emc_entry *ce, struct dp_netdev_flow *flow, > > ce->flow = NULL; > > } > > } > > - if (key) { > > - netdev_flow_key_clone(&ce->key, key); > > - } > > + netdev_flow_key_clone((struct netdev_flow_key *) ce->key, key); > > } > > > > static inline void > > -emc_insert(struct emc_cache *cache, const struct netdev_flow_key *key, > > - struct dp_netdev_flow *flow) > > +emc_probabilistic_insert(struct emc_cache *emc, > > + const struct netdev_flow_key *key, > > + struct dp_netdev_flow *flow) > > { > > - struct emc_entry *to_be_replaced = NULL; > > - struct emc_entry *current_entry; > > + const uint32_t threshold = UINT32_MAX/1000; > > > > - EMC_FOR_EACH_POS_WITH_HASH(cache, current_entry, key->hash) { > > - if (netdev_flow_key_equal(¤t_entry->key, key)) { > > - /* We found the entry with the 'mf' miniflow */ > > - emc_change_entry(current_entry, flow, NULL); > > - return; > > + if (random_uint32() <= threshold) { > > + > > + struct emc_entry *current_entry = emc_entry_get(emc, key->hash); > > + emc_change_entry(current_entry, key, flow); > > + } > > +} > > + > > +static inline struct dp_netdev_flow * > > +emc_lookup(struct emc_cache *emc, const struct netdev_flow_key *key) { > > + struct emc_entry *current_entry = emc_entry_get(emc, key->hash); > > + struct netdev_flow_key *current_key = > > + (struct netdev_flow_key *) current_entry->key; > > + > > + if (current_key->hash == key->hash > > + && emc_entry_alive(current_entry) > > + && netdev_flow_key_equal_mf(current_key, &key->mf)) { > > + > > + /* We found the entry with the 'key->mf' miniflow */ > > + return current_entry->flow; > > + } > > + return NULL; > > +} > > + > > +static inline struct dfc_entry * > > +dfc_entry_get(struct dfc_cache *cache, const uint32_t hash) { > > + return &cache->entries[hash & DFC_MASK]; } > > + > > +static inline bool > > +dfc_entry_alive(struct dfc_entry *ce) > > +{ > > + return ce->flow && !ce->flow->dead; } > > + > > +static void > > +dfc_clear_entry(struct dfc_entry *ce) > > +{ > > + if (ce->flow) { > > + dp_netdev_flow_unref(ce->flow); > > + ce->flow = NULL; > > + } > > +} > > + > > +static inline void > > +dfc_change_entry(struct dfc_entry *ce, struct dp_netdev_flow *flow) { > > + if (ce->flow != flow) { > > + if (ce->flow) { > > + dp_netdev_flow_unref(ce->flow); > > } > > > > - /* Replacement policy: put the flow in an empty (not alive) entry, > > or > > - * in the first entry where it can be */ > > - if (!to_be_replaced > > - || (emc_entry_alive(to_be_replaced) > > - && !emc_entry_alive(current_entry)) > > - || current_entry->key.hash < to_be_replaced->key.hash) { > > - to_be_replaced = current_entry; > > + if (dp_netdev_flow_ref(flow)) { > > + ce->flow = flow; > > + } else { > > + ce->flow = NULL; > > } > > } > > - /* We didn't find the miniflow in the cache. > > - * The 'to_be_replaced' entry is where the new flow will be stored */ > > - > > - emc_change_entry(to_be_replaced, flow, key); > > } > > > > static inline void > > -emc_probabilistic_insert(struct dp_netdev_pmd_thread *pmd, > > - const struct netdev_flow_key *key, > > - struct dp_netdev_flow *flow) > > +dfc_insert(struct dp_netdev_pmd_thread *pmd, > > + const struct netdev_flow_key *key, > > + struct dp_netdev_flow *flow) > > { > > - /* Insert an entry into the EMC based on probability value 'min'. By > > - * default the value is UINT32_MAX / 100 which yields an insertion > > - * probability of 1/100 ie. 1% */ > > + struct dfc_cache *cache = &pmd->flow_cache; > > + struct dfc_entry *current_entry; > > + > > + current_entry = dfc_entry_get(cache, key->hash); > > + dfc_change_entry(current_entry, flow); > > +} > > + > > +static inline struct dp_netdev_flow * > > +dfc_lookup(struct dfc_cache *cache, const struct netdev_flow_key *key, > > + bool *exact_match) > > +{ > > + struct dp_netdev_flow *flow; > > > > - uint32_t min; > > - atomic_read_relaxed(&pmd->dp->emc_insert_min, &min); > > + /* Try an EMC lookup first. */ > > + flow = emc_lookup(&cache->emc_cache, key); > > + if (flow) { > > + *exact_match = true; > > + return flow; > > + } > > + > > + /* EMC lookup not successful: try DFC lookup. */ > > + struct dfc_entry *current_entry = dfc_entry_get(cache, key->hash); > > + flow = current_entry->flow; > > > > - if (min && random_uint32() <= min) { > > - emc_insert(&pmd->flow_cache, key, flow); > > + if (dfc_entry_alive(current_entry) && > > + dpcls_rule_matches_key(&flow->cr, key)) { > > + > > + /* Found a match in DFC. Insert into EMC for subsequent lookups. > > + * We use probabilistic insertion here so that mainly elephant > > + * flows enter EMC. */ > > + emc_probabilistic_insert(&cache->emc_cache, key, flow); > > + *exact_match = false; > > + return flow; > > + } else { > > + > > + /* No match. Need to go to DPCLS lookup. */ > > + return NULL; > > } > > } > > > > -static inline struct dp_netdev_flow * > > -emc_lookup(struct emc_cache *cache, const struct netdev_flow_key *key) > > +/* Check and clear dead flow references slowly (one entry at each > > + * invocation). */ > > +static void > > +emc_slow_sweep(struct emc_cache *emc) > > { > > - struct emc_entry *current_entry; > > + struct emc_entry *entry = &emc->entries[emc->sweep_idx]; > > > > - EMC_FOR_EACH_POS_WITH_HASH(cache, current_entry, key->hash) { > > - if (current_entry->key.hash == key->hash > > - && emc_entry_alive(current_entry) > > - && netdev_flow_key_equal_mf(¤t_entry->key, &key->mf)) { > > + if (!emc_entry_alive(entry)) { > > + emc_clear_entry(entry); > > + } > > + emc->sweep_idx = (emc->sweep_idx + 1) & EMC_MASK; > > +} > > > > - /* We found the entry with the 'key->mf' miniflow */ > > - return current_entry->flow; > > - } > > +static void > > +dfc_slow_sweep(struct dfc_cache *cache) > > +{ > > + /* Sweep the EMC so that both finish in the same time. */ > > + if ((cache->sweep_idx & (DFC_ENTRIES/EMC_ENTRIES - 1)) == 0) { > > + emc_slow_sweep(&cache->emc_cache); > > } > > > > - return NULL; > > + struct dfc_entry *entry = &cache->entries[cache->sweep_idx]; > > + if (!dfc_entry_alive(entry)) { > > + dfc_clear_entry(entry); > > + } > > + cache->sweep_idx = (cache->sweep_idx + 1) & DFC_MASK; > > } > > > > static struct dp_netdev_flow * > > @@ -4048,7 +4165,7 @@ pmd_thread_main(void *f_) > > ovs_numa_thread_setaffinity_core(pmd->core_id); > > dpdk_set_lcore_id(pmd->core_id); > > poll_cnt = pmd_load_queues_and_ports(pmd, &poll_list); > > - emc_cache_init(&pmd->flow_cache); > > + dfc_cache_init(&pmd->flow_cache); > > reload: > > pmd_alloc_static_tx_qid(pmd); > > > > @@ -4078,17 +4195,16 @@ reload: > > : PMD_CYCLES_IDLE); > > } > > > > - if (lc++ > 1024) { > > - bool reload; > > + dfc_slow_sweep(&pmd->flow_cache); > > > > + if (lc++ > 1024) { > > lc = 0; > > > > coverage_try_clear(); > > dp_netdev_pmd_try_optimize(pmd, poll_list, poll_cnt); > > - if (!ovsrcu_try_quiesce()) { > > - emc_cache_slow_sweep(&pmd->flow_cache); > > - } > > + ovsrcu_try_quiesce(); > > > > + bool reload; > > atomic_read_relaxed(&pmd->reload, &reload); > > if (reload) { > > break; > > @@ -4110,7 +4226,7 @@ reload: > > goto reload; > > } > > > > - emc_cache_uninit(&pmd->flow_cache); > > + dfc_cache_uninit(&pmd->flow_cache); > > free(poll_list); > > pmd_free_cached_ports(pmd); > > return NULL; > > @@ -4544,7 +4660,7 @@ dp_netdev_configure_pmd(struct > > dp_netdev_pmd_thread *pmd, struct dp_netdev *dp, > > /* init the 'flow_cache' since there is no > > * actual thread created for NON_PMD_CORE_ID. */ > > if (core_id == NON_PMD_CORE_ID) { > > - emc_cache_init(&pmd->flow_cache); > > + dfc_cache_init(&pmd->flow_cache); > > pmd_alloc_static_tx_qid(pmd); > > } > > cmap_insert(&dp->poll_threads, CONST_CAST(struct cmap_node *, > > &pmd->node), > > @@ -4586,7 +4702,7 @@ dp_netdev_del_pmd(struct dp_netdev *dp, struct > > dp_netdev_pmd_thread *pmd) > > * but extra cleanup is necessary */ > > if (pmd->core_id == NON_PMD_CORE_ID) { > > ovs_mutex_lock(&dp->non_pmd_mutex); > > - emc_cache_uninit(&pmd->flow_cache); > > + dfc_cache_uninit(&pmd->flow_cache); > > pmd_free_cached_ports(pmd); > > pmd_free_static_tx_qid(pmd); > > ovs_mutex_unlock(&dp->non_pmd_mutex); > > @@ -4896,7 +5012,7 @@ dp_netdev_queue_batches(struct dp_packet *pkt, > > packet_batch_per_flow_update(batch, pkt, mf); > > } > > > > -/* Try to process all ('cnt') the 'packets' using only the exact match > > cache > > +/* Try to process all ('cnt') the 'packets' using only the PMD 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 > > * beginning of the 'packets' array. > > @@ -4911,19 +5027,20 @@ dp_netdev_queue_batches(struct dp_packet > > *pkt, > > * will be ignored. > > */ > > static inline size_t > > -emc_processing(struct dp_netdev_pmd_thread *pmd, > > +dfc_processing(struct dp_netdev_pmd_thread *pmd, > > struct dp_packet_batch *packets_, > > struct netdev_flow_key *keys, > > struct packet_batch_per_flow batches[], size_t *n_batches, > > bool md_is_valid, odp_port_t port_no) > > { > > - struct emc_cache *flow_cache = &pmd->flow_cache; > > + struct dfc_cache *flow_cache = &pmd->flow_cache; > > struct netdev_flow_key *key = &keys[0]; > > - size_t n_missed = 0, n_dropped = 0; > > + size_t n_missed = 0, n_dfc_hit = 0, n_emc_hit = 0; > > struct dp_packet *packet; > > const size_t cnt = dp_packet_batch_size(packets_); > > uint32_t cur_min; > > int i; > > + bool exact_match; > > > > atomic_read_relaxed(&pmd->dp->emc_insert_min, &cur_min); > > > > @@ -4932,7 +5049,6 @@ emc_processing(struct dp_netdev_pmd_thread > > *pmd, > > > > if (OVS_UNLIKELY(dp_packet_size(packet) < ETH_HEADER_LEN)) { > > dp_packet_delete(packet); > > - n_dropped++; > > continue; > > } > > > > @@ -4948,7 +5064,7 @@ emc_processing(struct dp_netdev_pmd_thread > > *pmd, > > } > > miniflow_extract(packet, &key->mf); > > key->len = 0; /* Not computed yet. */ > > - /* If EMC is disabled skip hash computation and emc_lookup */ > > + /* If DFC is disabled skip hash computation and DFC lookup */ > > if (cur_min) { > > if (!md_is_valid) { > > key->hash = > > dpif_netdev_packet_get_rss_hash_orig_pkt(packet, > > @@ -4956,11 +5072,16 @@ emc_processing(struct dp_netdev_pmd_thread > > *pmd, > > } else { > > key->hash = dpif_netdev_packet_get_rss_hash(packet, > > &key->mf); > > } > > - flow = emc_lookup(flow_cache, key); > > + flow = dfc_lookup(flow_cache, key, &exact_match); > > } else { > > flow = NULL; > > } > > if (OVS_LIKELY(flow)) { > > + if (exact_match) { > > + n_emc_hit++; > > + } else { > > + n_dfc_hit++; > > + } > > dp_netdev_queue_batches(packet, flow, &key->mf, batches, > > n_batches); > > } else { > > @@ -4974,8 +5095,8 @@ emc_processing(struct dp_netdev_pmd_thread > > *pmd, > > } > > } > > > > - dp_netdev_count_packet(pmd, DP_STAT_EXACT_HIT, > > - cnt - n_dropped - n_missed); > > + dp_netdev_count_packet(pmd, DP_STAT_EXACT_HIT, n_emc_hit); > > + dp_netdev_count_packet(pmd, DP_STAT_DFC_HIT, n_dfc_hit); > > > > return dp_packet_batch_size(packets_); > > } > > @@ -5044,7 +5165,7 @@ handle_packet_upcall(struct > > dp_netdev_pmd_thread *pmd, > > add_actions->size); > > } > > ovs_mutex_unlock(&pmd->flow_mutex); > > - emc_probabilistic_insert(pmd, key, netdev_flow); > > + dfc_insert(pmd, key, netdev_flow); > > } > > } > > > > @@ -5136,7 +5257,7 @@ fast_path_processing(struct > > dp_netdev_pmd_thread *pmd, > > > > flow = dp_netdev_flow_cast(rules[i]); > > > > - emc_probabilistic_insert(pmd, &keys[i], flow); > > + dfc_insert(pmd, &keys[i], flow); > > dp_netdev_queue_batches(packet, flow, &keys[i].mf, batches, > > n_batches); > > } > > > > @@ -5169,7 +5290,7 @@ dp_netdev_input__(struct > > dp_netdev_pmd_thread *pmd, > > odp_port_t in_port; > > > > n_batches = 0; > > - emc_processing(pmd, packets, keys, batches, &n_batches, > > + dfc_processing(pmd, packets, keys, batches, &n_batches, > > md_is_valid, port_no); > > if (!dp_packet_batch_is_empty(packets)) { > > /* Get ingress port from first packet's metadata. */ > > @@ -6063,7 +6184,7 @@ dpcls_remove(struct dpcls *cls, struct dpcls_rule > > *rule) > > > > /* Returns true if 'target' satisfies 'key' in 'mask', that is, if each > > 1-bit > > * in 'mask' the values in 'key' and 'target' are the same. */ > > -static inline bool > > +static bool > > dpcls_rule_matches_key(const struct dpcls_rule *rule, > > const struct netdev_flow_key *target) > > { > > -- > > 1.9.1 > > > > > > _______________________________________________ > > dev mailing list > > [email protected] > > https://mail.openvswitch.org/mailman/listinfo/ovs-dev _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
