From 88bf179aa3f3fa89822edcd9b882e0f06d39bf08 Mon Sep 17 00:00:00 2001 From: Alex Wang Date: Thu, 3 Apr 2014 10:20:44 -0700 Subject: bfd/cfm: Check status change before update status to database. This commit adds boolean flag in bfd/cfm module for checking status change. If there is no status change, the current update to OVS database will skip the bfd/cfm session. In the experiment with 5K bfd sessions, when one session is flapping at rate of every 0.3 second, this patch reduces the cpu utilization of the ovs-vswitchd thread from 13 to 6. Signed-off-by: Alex Wang Acked-by: Joe Stringer --- lib/bfd.c | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) (limited to 'lib/bfd.c') diff --git a/lib/bfd.c b/lib/bfd.c index 8bfe38584..e3e3ae5f1 100644 --- a/lib/bfd.c +++ b/lib/bfd.c @@ -213,6 +213,10 @@ struct bfd { long long int decay_detect_time; /* Decay detection time. */ uint64_t flap_count; /* Counts bfd forwarding flaps. */ + + /* True when the variables returned by bfd_get_status() are changed + * since last check. */ + bool status_changed; }; static struct ovs_mutex mutex = OVS_MUTEX_INITIALIZER; @@ -240,6 +244,7 @@ static void bfd_put_details(struct ds *, const struct bfd *) static uint64_t bfd_rx_packets(const struct bfd *) OVS_REQUIRES(mutex); static void bfd_try_decay(struct bfd *) OVS_REQUIRES(mutex); static void bfd_decay_update(struct bfd *) OVS_REQUIRES(mutex); +static void bfd_status_changed(struct bfd *) OVS_REQUIRES(mutex); static void bfd_forwarding_if_rx_update(struct bfd *) OVS_REQUIRES(mutex); static void bfd_unixctl_show(struct unixctl_conn *, int argc, @@ -279,6 +284,20 @@ bfd_account_rx(struct bfd *bfd, const struct dpif_flow_stats *stats) } } +/* Returns and resets the 'bfd->status_changed'. */ +bool +bfd_check_status_change(struct bfd *bfd) OVS_EXCLUDED(mutex) +{ + bool ret; + + ovs_mutex_lock(&mutex); + ret = bfd->status_changed; + bfd->status_changed = false; + ovs_mutex_unlock(&mutex); + + return ret; +} + /* Returns a 'smap' of key value pairs representing the status of 'bfd' * intended for the OVS database. */ void @@ -749,7 +768,7 @@ bfd_process_packet(struct bfd *bfd, const struct flow *flow, } if (bfd->rmt_state != rmt_state) { - seq_change(connectivity_seq_get()); + bfd_status_changed(bfd); } bfd->rmt_disc = ntohl(msg->my_disc); @@ -872,7 +891,7 @@ bfd_forwarding__(struct bfd *bfd) OVS_REQUIRES(mutex) && bfd->rmt_diag != DIAG_RCPATH_DOWN; if (bfd->last_forwarding != last_forwarding) { bfd->flap_count++; - seq_change(connectivity_seq_get()); + bfd_status_changed(bfd); } return bfd->last_forwarding; } @@ -1085,7 +1104,7 @@ bfd_set_state(struct bfd *bfd, enum state state, enum diag diag) bfd_decay_update(bfd); } - seq_change(connectivity_seq_get()); + bfd_status_changed(bfd); } } @@ -1132,6 +1151,14 @@ bfd_decay_update(struct bfd * bfd) OVS_REQUIRES(mutex) bfd->decay_detect_time = MAX(bfd->decay_min_rx, 2000) + time_msec(); } +/* Records the status change and changes the global connectivity seq. */ +static void +bfd_status_changed(struct bfd *bfd) OVS_REQUIRES(mutex) +{ + seq_change(connectivity_seq_get()); + bfd->status_changed = true; +} + static void bfd_forwarding_if_rx_update(struct bfd *bfd) OVS_REQUIRES(mutex) { @@ -1279,9 +1306,11 @@ bfd_unixctl_set_forwarding_override(struct unixctl_conn *conn, int argc, goto out; } bfd->forwarding_override = forwarding_override; + bfd_status_changed(bfd); } else { HMAP_FOR_EACH (bfd, node, all_bfds) { bfd->forwarding_override = forwarding_override; + bfd_status_changed(bfd); } } -- cgit v1.2.1