Before this commit, emc_processing() copied a netdev_flow_key if there was no exact-match cache (EMC) hit. This commit eliminates the copy by constructing the netdev_flow_key in the place it would be copied.
Found by inspection. Shahbaz (CCed) reports that this reduces the cost of an EMC miss by 72 cycles in his test case in which the EMC is disabled. Presumably this is similarly valuable in cases where the EMC merely has few hits. CC: Muhammad Shahbaz <mshah...@cs.princeton.edu> Signed-off-by: Ben Pfaff <b...@ovn.org> --- AUTHORS | 1 + lib/dpif-netdev.c | 17 ++++++++--------- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/AUTHORS b/AUTHORS index 7ae64d3..420aa2d 100644 --- a/AUTHORS +++ b/AUTHORS @@ -352,6 +352,7 @@ Mike Kruze mkr...@nicira.com Min Chen ustcer.tonyc...@gmail.com Mikael Doverhag mdover...@nicira.com Mrinmoy Das mr...@ixiacom.com +Muhammad Shahbaz mshah...@cs.princeton.edu Murali R muralir...@gmail.com Nagi Reddy Jonnala njonn...@brocade.com Niels van Adrichem n.l.m.vanadric...@tudelft.nl diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c index cd72e62..97c4cde 100644 --- a/lib/dpif-netdev.c +++ b/lib/dpif-netdev.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc. + * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2016 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -3210,7 +3210,6 @@ emc_processing(struct dp_netdev_pmd_thread *pmd, struct dp_packet **packets, struct packet_batch batches[], size_t *n_batches) { struct emc_cache *flow_cache = &pmd->flow_cache; - struct netdev_flow_key key; size_t i, notfound_cnt = 0; for (i = 0; i < cnt; i++) { @@ -3226,20 +3225,20 @@ emc_processing(struct dp_netdev_pmd_thread *pmd, struct dp_packet **packets, OVS_PREFETCH(dp_packet_data(packets[i+1])); } - miniflow_extract(packets[i], &key.mf); - key.len = 0; /* Not computed yet. */ - key.hash = dpif_netdev_packet_get_rss_hash(packets[i], &key.mf); + struct netdev_flow_key *key = &keys[notfound_cnt]; + miniflow_extract(packets[i], &key->mf); + key->len = 0; /* Not computed yet. */ + key->hash = dpif_netdev_packet_get_rss_hash(packets[i], &key->mf); - flow = emc_lookup(flow_cache, &key); + flow = emc_lookup(flow_cache, key); if (OVS_LIKELY(flow)) { - dp_netdev_queue_batches(packets[i], flow, &key.mf, batches, + dp_netdev_queue_batches(packets[i], flow, &key->mf, batches, n_batches); } else { if (i != notfound_cnt) { dp_packet_swap(&packets[i], &packets[notfound_cnt]); } - - keys[notfound_cnt++] = key; + notfound_cnt++; } } -- 2.1.3 _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev