Message ID | 20190225161815.59733-2-harry.van.haaren@intel.com |
---|---|
State | Superseded |
Headers | show |
Series | dpcls subtable func pointers | expand |
Bleep bloop. Greetings Harry van Haaren, I am a robot and I have tried out your patch. Thanks for your contribution. I encountered some error that I wasn't expecting. See the details below. checkpatch: ERROR: C99 style comment #110 FILE: lib/dpif-netdev.c:7870: //lookups_match += subtable_pos; Lines checked: 203, Warnings: 0, Errors: 1 Please check this out. If you feel there has been an error, please email aconole@bytheb.org Thanks, 0-day Robot
On 25 Feb 2019, at 17:18, Harry van Haaren wrote: > This allows plugging-in of different subtable hash-lookup-verify > routines, and allows special casing of those functions based on > known context (eg: # of bits set) of the specific subtable. See two small style comments below, the rest looks fine to me. I still would like to run my performance tests on the full patchset. Will try to do this early next week, while reviewing the rest of the patchset. > Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com> > --- > lib/dpif-netdev.c | 127 > +++++++++++++++++++++++++++++++--------------- > 1 file changed, 87 insertions(+), 40 deletions(-) > > diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c > index 77ac1d2c1..2ae380640 100644 > --- a/lib/dpif-netdev.c > +++ b/lib/dpif-netdev.c > @@ -7579,6 +7579,27 @@ dpif_dummy_register(enum dummy_level level) > > /* Datapath Classifier. */ > > +/* forward declaration for lookup_func typedef */ > +struct dpcls_subtable; > + > +/** Lookup function for a subtable in the dpcls. This function is > called ^^ Guess one * would be enough and matches the comment style earlier in the file. > + * by each subtable with an array of packets, and a bitmask of > packets to > + * perform the lookup on. Using a function pointer gives flexibility > to > + * optimize the lookup function based on subtable properties and the > + * CPU instruction set available at runtime. > + */ > +typedef uint32_t (*dpcls_subtable_lookup_func)(struct dpcls_subtable > *subtable, > + uint32_t keys_map, const struct netdev_flow_key > *keys[], > + struct dpcls_rule **rules); > + > +/** Prototype for generic lookup func, using same code path as before > */ > +uint32_t > +dpcls_subtable_lookup_generic(struct dpcls_subtable *subtable, > + uint32_t keys_map, > + const struct netdev_flow_key *keys[], > + struct dpcls_rule **rules); > + > + > /* A set of rules that all have the same fields wildcarded. */ > struct dpcls_subtable { > /* The fields are only used by writers. */ > @@ -7588,6 +7609,13 @@ struct dpcls_subtable { > struct cmap rules; /* Contains "struct dpcls_rule"s. */ > uint32_t hit_cnt; /* Number of match hits in subtable > in current > optimization interval. */ > + > + /* the lookup function to use for this subtable. If there is a > known > + * property of the subtable (eg: only 3 bits of miniflow metadata > is > + * used for the lookup) then this can point at an optimized > version of > + * the lookup function for this particular subtable. */ > + dpcls_subtable_lookup_func lookup_func; > + > struct netdev_flow_key mask; /* Wildcards for fields (const). */ > /* 'mask' must be the last field, additional space is allocated > here. */ > }; > @@ -7641,6 +7669,10 @@ dpcls_create_subtable(struct dpcls *cls, const > struct netdev_flow_key *mask) > cmap_init(&subtable->rules); > subtable->hit_cnt = 0; > netdev_flow_key_clone(&subtable->mask, mask); > + > + /* decide which hash/lookup/verify function to use */ > + subtable->lookup_func = dpcls_subtable_lookup_generic; > + > cmap_insert(&cls->subtables_map, &subtable->cmap_node, > mask->hash); > /* Add the new subtable at the end of the pvector (with no hits > yet) */ > pvector_insert(&cls->subtables, subtable, 0); > @@ -7801,6 +7833,54 @@ dpcls_rule_matches_key(const struct dpcls_rule > *rule, > return true; > } > > +uint32_t > +dpcls_subtable_lookup_generic(struct dpcls_subtable *subtable, > + uint32_t keys_map, > + const struct netdev_flow_key *keys[], > + struct dpcls_rule **rules) > +{ > + int i; > + /* Compute hashes for the remaining keys. Each search-key is > + * masked with the subtable's mask to avoid hashing the > wildcarded > + * bits. */ > + uint32_t hashes[NETDEV_MAX_BURST]; > + ULLONG_FOR_EACH_1(i, keys_map) { > + hashes[i] = netdev_flow_key_hash_in_mask(keys[i], > + > &subtable->mask); > + } > + > + /* Lookup. */ > + const struct cmap_node *nodes[NETDEV_MAX_BURST]; > + uint32_t found_map = > + cmap_find_batch(&subtable->rules, keys_map, hashes, > nodes); > + /* Check results. When the i-th bit of found_map is set, it > means > + * that a set of nodes with a matching hash value was found > for the > + * i-th search-key. Due to possible hash collisions we need > to check > + * which of the found rules, if any, really matches our > masked > + * search-key. */ > + ULLONG_FOR_EACH_1(i, found_map) { > + struct dpcls_rule *rule; > + > + CMAP_NODE_FOR_EACH (rule, cmap_node, nodes[i]) { > + if (OVS_LIKELY(dpcls_rule_matches_key(rule, > keys[i]))) { > + rules[i] = rule; > + /* Even at 20 Mpps the 32-bit hit_cnt cannot wrap > + * within one second optimization interval. */ > + subtable->hit_cnt++; > + //lookups_match += subtable_pos; > + goto next; > + } > + } > + /* None of the found rules was a match. Reset the i-th > bit to > + * keep searching this key in the next subtable. */ > + ULLONG_SET0(found_map, i); /* Did not match. */ > + next: > + ; /* Keep Sparse happy. */ > + } > + > + return found_map; > +} > + > /* For each miniflow in 'keys' performs a classifier lookup writing > the result > * into the corresponding slot in 'rules'. If a particular entry in > 'keys' is > * NULL it is skipped. > @@ -7819,16 +7899,12 @@ dpcls_lookup(struct dpcls *cls, const struct > netdev_flow_key *keys[], > /* The received 'cnt' miniflows are the search-keys that will be > processed > * to find a matching entry into the available subtables. > * The number of bits in map_type is equal to NETDEV_MAX_BURST. > */ > - typedef uint32_t map_type; > -#define MAP_BITS (sizeof(map_type) * CHAR_BIT) > +#define MAP_BITS (sizeof(uint32_t) * CHAR_BIT) > BUILD_ASSERT_DECL(MAP_BITS >= NETDEV_MAX_BURST); > > struct dpcls_subtable *subtable; > > - map_type keys_map = TYPE_MAXIMUM(map_type); /* Set all bits. */ > - map_type found_map; > - uint32_t hashes[MAP_BITS]; > - const struct cmap_node *nodes[MAP_BITS]; > + uint32_t keys_map = TYPE_MAXIMUM(uint32_t); /* Set all bits. */ > > if (cnt != MAP_BITS) { > keys_map >>= MAP_BITS - cnt; /* Clear extra bits. */ > @@ -7845,41 +7921,10 @@ dpcls_lookup(struct dpcls *cls, const struct > netdev_flow_key *keys[], > * search-key, the search for that key can stop because the rules > are > * non-overlapping. */ > PVECTOR_FOR_EACH (subtable, &cls->subtables) { > - int i; > + /* call the subtable specific lookup function */ > + uint32_t found_map = > + subtable->lookup_func(subtable, keys_map, keys, > rules); > > - /* Compute hashes for the remaining keys. Each search-key is > - * masked with the subtable's mask to avoid hashing the > wildcarded > - * bits. */ > - ULLONG_FOR_EACH_1(i, keys_map) { > - hashes[i] = netdev_flow_key_hash_in_mask(keys[i], > - > &subtable->mask); > - } > - /* Lookup. */ > - found_map = cmap_find_batch(&subtable->rules, keys_map, > hashes, nodes); > - /* Check results. When the i-th bit of found_map is set, it > means > - * that a set of nodes with a matching hash value was found > for the > - * i-th search-key. Due to possible hash collisions we need > to check > - * which of the found rules, if any, really matches our > masked > - * search-key. */ > - ULLONG_FOR_EACH_1(i, found_map) { > - struct dpcls_rule *rule; > - > - CMAP_NODE_FOR_EACH (rule, cmap_node, nodes[i]) { > - if (OVS_LIKELY(dpcls_rule_matches_key(rule, > keys[i]))) { > - rules[i] = rule; > - /* Even at 20 Mpps the 32-bit hit_cnt cannot wrap > - * within one second optimization interval. */ > - subtable->hit_cnt++; > - lookups_match += subtable_pos; > - goto next; > - } > - } > - /* None of the found rules was a match. Reset the i-th > bit to > - * keep searching this key in the next subtable. */ > - ULLONG_SET0(found_map, i); /* Did not match. */ > - next: > - ; /* Keep Sparse happy. */ > - } > keys_map &= ~found_map; /* Clear the found rules. > */ > if (!keys_map) { > if (num_lookups_p) { > @@ -7889,6 +7934,8 @@ dpcls_lookup(struct dpcls *cls, const struct > netdev_flow_key *keys[], > } > subtable_pos++; > } > + > + One enter might be enough hereā¦ > if (num_lookups_p) { > *num_lookups_p = lookups_match; > } > -- > 2.17.1 > > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c index 77ac1d2c1..2ae380640 100644 --- a/lib/dpif-netdev.c +++ b/lib/dpif-netdev.c @@ -7579,6 +7579,27 @@ dpif_dummy_register(enum dummy_level level) /* Datapath Classifier. */ +/* forward declaration for lookup_func typedef */ +struct dpcls_subtable; + +/** Lookup function for a subtable in the dpcls. This function is called + * by each subtable with an array of packets, and a bitmask of packets to + * perform the lookup on. Using a function pointer gives flexibility to + * optimize the lookup function based on subtable properties and the + * CPU instruction set available at runtime. + */ +typedef uint32_t (*dpcls_subtable_lookup_func)(struct dpcls_subtable *subtable, + uint32_t keys_map, const struct netdev_flow_key *keys[], + struct dpcls_rule **rules); + +/** Prototype for generic lookup func, using same code path as before */ +uint32_t +dpcls_subtable_lookup_generic(struct dpcls_subtable *subtable, + uint32_t keys_map, + const struct netdev_flow_key *keys[], + struct dpcls_rule **rules); + + /* A set of rules that all have the same fields wildcarded. */ struct dpcls_subtable { /* The fields are only used by writers. */ @@ -7588,6 +7609,13 @@ struct dpcls_subtable { struct cmap rules; /* Contains "struct dpcls_rule"s. */ uint32_t hit_cnt; /* Number of match hits in subtable in current optimization interval. */ + + /* the lookup function to use for this subtable. If there is a known + * property of the subtable (eg: only 3 bits of miniflow metadata is + * used for the lookup) then this can point at an optimized version of + * the lookup function for this particular subtable. */ + dpcls_subtable_lookup_func lookup_func; + struct netdev_flow_key mask; /* Wildcards for fields (const). */ /* 'mask' must be the last field, additional space is allocated here. */ }; @@ -7641,6 +7669,10 @@ dpcls_create_subtable(struct dpcls *cls, const struct netdev_flow_key *mask) cmap_init(&subtable->rules); subtable->hit_cnt = 0; netdev_flow_key_clone(&subtable->mask, mask); + + /* decide which hash/lookup/verify function to use */ + subtable->lookup_func = dpcls_subtable_lookup_generic; + cmap_insert(&cls->subtables_map, &subtable->cmap_node, mask->hash); /* Add the new subtable at the end of the pvector (with no hits yet) */ pvector_insert(&cls->subtables, subtable, 0); @@ -7801,6 +7833,54 @@ dpcls_rule_matches_key(const struct dpcls_rule *rule, return true; } +uint32_t +dpcls_subtable_lookup_generic(struct dpcls_subtable *subtable, + uint32_t keys_map, + const struct netdev_flow_key *keys[], + struct dpcls_rule **rules) +{ + int i; + /* Compute hashes for the remaining keys. Each search-key is + * masked with the subtable's mask to avoid hashing the wildcarded + * bits. */ + uint32_t hashes[NETDEV_MAX_BURST]; + ULLONG_FOR_EACH_1(i, keys_map) { + hashes[i] = netdev_flow_key_hash_in_mask(keys[i], + &subtable->mask); + } + + /* Lookup. */ + const struct cmap_node *nodes[NETDEV_MAX_BURST]; + uint32_t found_map = + cmap_find_batch(&subtable->rules, keys_map, hashes, nodes); + /* Check results. When the i-th bit of found_map is set, it means + * that a set of nodes with a matching hash value was found for the + * i-th search-key. Due to possible hash collisions we need to check + * which of the found rules, if any, really matches our masked + * search-key. */ + ULLONG_FOR_EACH_1(i, found_map) { + struct dpcls_rule *rule; + + CMAP_NODE_FOR_EACH (rule, cmap_node, nodes[i]) { + if (OVS_LIKELY(dpcls_rule_matches_key(rule, keys[i]))) { + rules[i] = rule; + /* Even at 20 Mpps the 32-bit hit_cnt cannot wrap + * within one second optimization interval. */ + subtable->hit_cnt++; + //lookups_match += subtable_pos; + goto next; + } + } + /* None of the found rules was a match. Reset the i-th bit to + * keep searching this key in the next subtable. */ + ULLONG_SET0(found_map, i); /* Did not match. */ + next: + ; /* Keep Sparse happy. */ + } + + return found_map; +} + /* For each miniflow in 'keys' performs a classifier lookup writing the result * into the corresponding slot in 'rules'. If a particular entry in 'keys' is * NULL it is skipped. @@ -7819,16 +7899,12 @@ dpcls_lookup(struct dpcls *cls, const struct netdev_flow_key *keys[], /* The received 'cnt' miniflows are the search-keys that will be processed * to find a matching entry into the available subtables. * The number of bits in map_type is equal to NETDEV_MAX_BURST. */ - typedef uint32_t map_type; -#define MAP_BITS (sizeof(map_type) * CHAR_BIT) +#define MAP_BITS (sizeof(uint32_t) * CHAR_BIT) BUILD_ASSERT_DECL(MAP_BITS >= NETDEV_MAX_BURST); struct dpcls_subtable *subtable; - map_type keys_map = TYPE_MAXIMUM(map_type); /* Set all bits. */ - map_type found_map; - uint32_t hashes[MAP_BITS]; - const struct cmap_node *nodes[MAP_BITS]; + uint32_t keys_map = TYPE_MAXIMUM(uint32_t); /* Set all bits. */ if (cnt != MAP_BITS) { keys_map >>= MAP_BITS - cnt; /* Clear extra bits. */ @@ -7845,41 +7921,10 @@ dpcls_lookup(struct dpcls *cls, const struct netdev_flow_key *keys[], * search-key, the search for that key can stop because the rules are * non-overlapping. */ PVECTOR_FOR_EACH (subtable, &cls->subtables) { - int i; + /* call the subtable specific lookup function */ + uint32_t found_map = + subtable->lookup_func(subtable, keys_map, keys, rules); - /* Compute hashes for the remaining keys. Each search-key is - * masked with the subtable's mask to avoid hashing the wildcarded - * bits. */ - ULLONG_FOR_EACH_1(i, keys_map) { - hashes[i] = netdev_flow_key_hash_in_mask(keys[i], - &subtable->mask); - } - /* Lookup. */ - found_map = cmap_find_batch(&subtable->rules, keys_map, hashes, nodes); - /* Check results. When the i-th bit of found_map is set, it means - * that a set of nodes with a matching hash value was found for the - * i-th search-key. Due to possible hash collisions we need to check - * which of the found rules, if any, really matches our masked - * search-key. */ - ULLONG_FOR_EACH_1(i, found_map) { - struct dpcls_rule *rule; - - CMAP_NODE_FOR_EACH (rule, cmap_node, nodes[i]) { - if (OVS_LIKELY(dpcls_rule_matches_key(rule, keys[i]))) { - rules[i] = rule; - /* Even at 20 Mpps the 32-bit hit_cnt cannot wrap - * within one second optimization interval. */ - subtable->hit_cnt++; - lookups_match += subtable_pos; - goto next; - } - } - /* None of the found rules was a match. Reset the i-th bit to - * keep searching this key in the next subtable. */ - ULLONG_SET0(found_map, i); /* Did not match. */ - next: - ; /* Keep Sparse happy. */ - } keys_map &= ~found_map; /* Clear the found rules. */ if (!keys_map) { if (num_lookups_p) { @@ -7889,6 +7934,8 @@ dpcls_lookup(struct dpcls *cls, const struct netdev_flow_key *keys[], } subtable_pos++; } + + if (num_lookups_p) { *num_lookups_p = lookups_match; }
This allows plugging-in of different subtable hash-lookup-verify routines, and allows special casing of those functions based on known context (eg: # of bits set) of the specific subtable. Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com> --- lib/dpif-netdev.c | 127 +++++++++++++++++++++++++++++++--------------- 1 file changed, 87 insertions(+), 40 deletions(-)