> The study function runs all the available implementations > of miniflow_extract and makes a choice whose hitmask has > maximum hits and sets the mfex to that function.
Hi Amber/Harry, Thanks for the patch, a few comments inline below. > > Study can be run at runtime using the following command: > > $ ovs-appctl dpif-netdev/miniflow-parser-set study > > Signed-off-by: Kumar Amber <kumar.am...@intel.com> > Co-authored-by: Harry van Haaren <harry.van.haa...@intel.com> > Signed-off-by: Harry van Haaren <harry.van.haa...@intel.com> > --- > lib/automake.mk | 1 + > lib/dpif-netdev-extract-study.c | 119 ++++++++++++++++++++++++++++++ > lib/dpif-netdev-private-extract.c | 5 ++ > lib/dpif-netdev-private-extract.h | 14 +++- > 4 files changed, 138 insertions(+), 1 deletion(-) > create mode 100644 lib/dpif-netdev-extract-study.c > > diff --git a/lib/automake.mk b/lib/automake.mk > index 6657b9ae5..3080bb04a 100644 > --- a/lib/automake.mk > +++ b/lib/automake.mk > @@ -114,6 +114,7 @@ lib_libopenvswitch_la_SOURCES = \ > lib/dpif-netdev.c \ > lib/dpif-netdev.h \ > lib/dpif-netdev-private-dfc.c \ > + lib/dpif-netdev-extract-study.c \ Headers should be added alphabetically. > lib/dpif-netdev-private-dfc.h \ > lib/dpif-netdev-private-dpcls.h \ > lib/dpif-netdev-private-dpif.c \ > diff --git a/lib/dpif-netdev-extract-study.c b/lib/dpif-netdev-extract-study.c > new file mode 100644 > index 000000000..d063d040c > --- /dev/null > +++ b/lib/dpif-netdev-extract-study.c > @@ -0,0 +1,119 @@ > +/* > + * Copyright (c) 2021 Intel. > + * > + * Licensed under the Apache License, Version 2.0 (the "License"); > + * you may not use this file except in compliance with the License. > + * You may obtain a copy of the License at: > + * > + * http://www.apache.org/licenses/LICENSE-2.0 > + * > + * Unless required by applicable law or agreed to in writing, software > + * distributed under the License is distributed on an "AS IS" BASIS, > + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or > implied. > + * See the License for the specific language governing permissions and > + * limitations under the License. > + */ > + > +#include <config.h> > +#include <errno.h> > +#include <stdint.h> > +#include <string.h> > + > +#include "dpif-netdev-private-extract.h" > +#include "dpif-netdev-private-thread.h" > +#include "openvswitch/vlog.h" > +#include "ovs-thread.h" > + > +VLOG_DEFINE_THIS_MODULE(dpif_mfex_extract_study); > + > +/* Max size of packets to be compared. */ > +#define MFEX_MAX_COUNT (128) > + > +/* This value is the threshold for the amount of packets that > + * must hit on the optimized miniflow extract before it will be > + * accepted and used in the datapath after the study phase. */ > +#define MFEX_MIN_HIT_COUNT_FOR_USE (MFEX_MAX_COUNT / 2) > + > +/* Struct to hold miniflow study stats. */ > +struct study_stats { > + uint32_t pkt_count; > + uint32_t impl_hitcount[MFEX_IMPLS_MAX_SIZE]; > +}; > + > +/* Define per thread data to hold the study stats. */ > +DEFINE_PER_THREAD_MALLOCED_DATA(struct study_stats *, study_stats); > + > +/* Allocate per thread PMD pointer space for study_stats. */ > +static inline struct study_stats * > +get_study_stats(void) Would maybe suggest a name change here, get_study_stats sounds as if info is being returned whereas whats actually happening is that the memory for the stats are being provisioned. > +{ > + struct study_stats *stats = study_stats_get(); > + if (OVS_UNLIKELY(!stats)) { > + stats = xzalloc(sizeof *stats); > + study_stats_set_unsafe(stats); Can you explain why above is set unsafe? Where does that function originate from? > + } > + return stats; > +} > + > +uint32_t > +mfex_study_traffic(struct dp_packet_batch *packets, > + struct netdev_flow_key *keys, > + uint32_t keys_size, odp_port_t in_port, > + void *pmd_handle) > +{ > + uint32_t hitmask = 0; > + uint32_t mask = 0; > + struct dp_netdev_pmd_thread *pmd = pmd_handle; > + struct dpif_miniflow_extract_impl *miniflow_funcs; > + uint32_t impl_count = dpif_miniflow_extract_info_get(&miniflow_funcs); > + struct study_stats *stats = get_study_stats(); > + > + /* Run traffic optimized miniflow_extract to collect the hitmask > + * to be compared after certain packets have been hit to choose > + * the best miniflow_extract version for that traffic. */ For the comment above would prefer to keep with the OVS coding style and close comment vertically aligned. https://docs.openvswitch.org/en/latest/internals/contributing/coding-style/#comments /* * */ > + for (int i = MFEX_IMPL_START_IDX; i < impl_count; i++) { > + if (miniflow_funcs[i].available) { > + hitmask = miniflow_funcs[i].extract_func(packets, keys, > keys_size, > + in_port, pmd_handle); > + stats->impl_hitcount[i] += count_1bits(hitmask); > + > + /* If traffic is not classified than we dont overwrite the keys Typo above than -> then > + * array in minfiflow implementations so its safe to create a > + * mask for all those packets whose miniflow have been created. > */ > + mask |= hitmask; > + } > + } > + stats->pkt_count += dp_packet_batch_size(packets); > + > + /* Choose the best implementation after a minimum packets have been > + * processed. */ > + if (stats->pkt_count >= MFEX_MAX_COUNT) { > + uint32_t best_func_index = MFEX_IMPL_START_IDX; > + uint32_t max_hits = 0; > + for (int i = MFEX_IMPL_START_IDX; i < impl_count; i++) { > + if (stats->impl_hitcount[i] > max_hits) { > + max_hits = stats->impl_hitcount[i]; > + best_func_index = i; > + } > + } > + > + if (max_hits >= MFEX_MIN_HIT_COUNT_FOR_USE) { > + /* Set the implementation to index with max_hits. */ > + pmd->miniflow_extract_opt = > + miniflow_funcs[best_func_index].extract_func; > + VLOG_INFO("MFEX study chose impl %s: (hits %d/%d pkts)\n", > + miniflow_funcs[best_func_index].name, max_hits, > + stats->pkt_count); > + } else { > + /* Set the implementation to null for default miniflow. */ > + pmd->miniflow_extract_opt = NULL; > + VLOG_INFO("Not enough packets matched (%d/%d), disabling" > + " optimized MFEX.\n", max_hits, stats->pkt_count); > + } > + /* Reset stats so that study function can be called again > + * for next traffic type and optimal function ptr can be > + * choosen. */ Typo, chosen -> chosen. BR Ian > + memset(stats, 0, sizeof(struct study_stats)); > + } > + return mask; > +} > diff --git a/lib/dpif-netdev-private-extract.c > b/lib/dpif-netdev-private-extract.c > index 0741c19f9..d86268a1d 100644 > --- a/lib/dpif-netdev-private-extract.c > +++ b/lib/dpif-netdev-private-extract.c > @@ -42,6 +42,11 @@ static struct dpif_miniflow_extract_impl mfex_impls[] = { > .extract_func = NULL, > .name = "disable", > }, > + { > + .probe = NULL, > + .extract_func = mfex_study_traffic, > + .name = "study", > + }, > }; > > BUILD_ASSERT_DECL(MFEX_IMPLS_MAX_SIZE > ARRAY_SIZE(mfex_impls)); > diff --git a/lib/dpif-netdev-private-extract.h > b/lib/dpif-netdev-private-extract.h > index 455a7b590..3ada413bb 100644 > --- a/lib/dpif-netdev-private-extract.h > +++ b/lib/dpif-netdev-private-extract.h > @@ -27,7 +27,7 @@ > /* Skip the autovalidator study and null when iterating all available > * miniflow implementations. > */ > -#define MFEX_IMPL_START_IDX (1) > +#define MFEX_IMPL_START_IDX (3) > > /* Forward declarations. */ > struct dp_packet; > @@ -106,4 +106,16 @@ dpif_miniflow_extract_autovalidator(struct > dp_packet_batch *batch, > uint32_t keys_size, odp_port_t in_port, > void *pmd_handle); > > +/* Retrieve the number of packets by studying packets using different > miniflow > + * implementations to choose the best implementation using the maximum > hitmask > + * count. > + * On error, returns a zero for no packets. > + * On success, returns mask of the packets hit. > + */ > +uint32_t > +mfex_study_traffic(struct dp_packet_batch *packets, > + struct netdev_flow_key *keys, > + uint32_t keys_size, odp_port_t in_port, > + void *pmd_handle); > + > #endif /* DPIF_NETDEV_AVX512_EXTRACT */ > -- > 2.25.1 > > _______________________________________________ > dev mailing list > d...@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
