From 5d3a4e00178189d827156be32ebb39fc80dc027b Mon Sep 17 00:00:00 2001 From: Numan Siddique Date: Mon, 16 Dec 2024 10:27:00 -0800 Subject: [PATCH] ovn-controller dns-cache: Improve dns caching using cmaps. Its possible for pinctrl handling for DNS packets to be blocked if the ovn-controller main thread has acquired the dns cache mutex during the recompute. This patch improves the DNS packet handling by using cmap instead of hmap to maintain the dns cache. With this, there is no need to maintain a mutex. Since cmaps use OVSRCU_TYPE, in order to safely free the cmap data, we need to manage the quiesce state for both the main ovn-controller thread and pinctrl thread. ovsrcu_quiesce_start() is called before calling poll_block() and ovsrcu_quiesce_end() is called at the start of the while for both these threads. Suggested-by: Ales Musil Acked-by: Ales Musil Signed-off-by: Numan Siddique (cherry picked from commit eba60b27864875e96a9367ea6a49325edcc6587b) --- controller/ovn-controller.c | 3 + controller/ovn-dns.c | 144 +++++++++++++++--------------------- controller/pinctrl.c | 4 + 3 files changed, 67 insertions(+), 84 deletions(-) diff --git a/controller/ovn-controller.c b/controller/ovn-controller.c index 1904d64ce0..3abfb9a8e6 100644 --- a/controller/ovn-controller.c +++ b/controller/ovn-controller.c @@ -5376,6 +5376,8 @@ main(int argc, char *argv[]) /* Main loop. */ bool sb_monitor_all = false; while (!exit_args.exiting) { + ovsrcu_quiesce_end(); + memory_run(); if (memory_should_report()) { struct simap usage = SIMAP_INITIALIZER(&usage); @@ -5863,6 +5865,7 @@ main(int argc, char *argv[]) loop_done: memory_wait(); + ovsrcu_quiesce_start(); poll_block(); if (should_service_stop()) { exit_args.exiting = true; diff --git a/controller/ovn-dns.c b/controller/ovn-dns.c index 026d9bc647..bfeef5a747 100644 --- a/controller/ovn-dns.c +++ b/controller/ovn-dns.c @@ -18,6 +18,7 @@ /* OVS includes */ #include "include/openvswitch/shash.h" #include "include/openvswitch/thread.h" +#include "lib/cmap.h" #include "openvswitch/vlog.h" /* OVN includes. */ @@ -28,7 +29,7 @@ VLOG_DEFINE_THIS_MODULE(ovndns); /* Internal DNS cache entry for each SB DNS record. */ struct dns_data { - struct hmap_node hmap_node; + struct cmap_node cmap_node; struct uuid uuid; uint64_t *dps; size_t n_dps; @@ -38,114 +39,87 @@ struct dns_data { }; /* shash of 'struct dns_data'. */ -static struct hmap dns_cache_ = HMAP_INITIALIZER(&dns_cache_); - -/* Mutex to protect dns_cache_. */ -static struct ovs_mutex dns_cache_mutex = OVS_MUTEX_INITIALIZER; +static struct cmap dns_cache_; static void update_cache_with_dns_rec(const struct sbrec_dns *, struct dns_data *, const struct uuid *uuid, - struct hmap *dns_cache); -static struct dns_data *dns_data_find(const struct uuid *uuid); + struct cmap *dns_cache); +static struct dns_data *dns_data_find(const struct uuid *uuid, + const struct cmap *); static struct dns_data *dns_data_alloc(struct uuid uuid); static void dns_data_destroy(struct dns_data *dns_data); +static void destroy_dns_cache(struct cmap *dns_cache); void ovn_dns_cache_init(void) { + cmap_init(&dns_cache_); } void ovn_dns_cache_destroy(void) { - ovs_mutex_lock(&dns_cache_mutex); - struct dns_data *dns_data; - HMAP_FOR_EACH_POP (dns_data, hmap_node, &dns_cache_) { - dns_data_destroy(dns_data); - } - hmap_destroy(&dns_cache_); - ovs_mutex_unlock(&dns_cache_mutex); + destroy_dns_cache(&dns_cache_); + cmap_destroy(&dns_cache_); } void ovn_dns_sync_cache(const struct sbrec_dns_table *dns_table) { - ovs_mutex_lock(&dns_cache_mutex); - struct dns_data *dns_data; - HMAP_FOR_EACH (dns_data, hmap_node, &dns_cache_) { - dns_data->delete = true; + const struct sbrec_dns *sbrec_dns; + struct dns_data *existing; + + CMAP_FOR_EACH (existing, cmap_node, &dns_cache_) { + existing->delete = true; } - const struct sbrec_dns *sbrec_dns; SBREC_DNS_TABLE_FOR_EACH (sbrec_dns, dns_table) { const struct uuid *uuid = &sbrec_dns->header_.uuid; - dns_data = dns_data_find(uuid); - if (!dns_data) { - dns_data = dns_data_alloc(*uuid); - hmap_insert(&dns_cache_, &dns_data->hmap_node, uuid_hash(uuid)); - } else { - free(dns_data->dps); - } - - dns_data->delete = false; - - if (!smap_equal(&dns_data->records, &sbrec_dns->records)) { - smap_destroy(&dns_data->records); - smap_clone(&dns_data->records, &sbrec_dns->records); - } - - if (!smap_equal(&dns_data->options, &sbrec_dns->options)) { - smap_destroy(&dns_data->options); - smap_clone(&dns_data->options, &sbrec_dns->options); - } - - dns_data->n_dps = sbrec_dns->n_datapaths; - dns_data->dps = xcalloc(dns_data->n_dps, sizeof(uint64_t)); - for (size_t i = 0; i < sbrec_dns->n_datapaths; i++) { - dns_data->dps[i] = sbrec_dns->datapaths[i]->tunnel_key; - } + existing = dns_data_find(uuid, &dns_cache_); + update_cache_with_dns_rec(sbrec_dns, existing, uuid, + &dns_cache_); } - HMAP_FOR_EACH_SAFE (dns_data, hmap_node, &dns_cache_) { - if (dns_data->delete) { - hmap_remove(&dns_cache_, &dns_data->hmap_node); - dns_data_destroy(dns_data); + CMAP_FOR_EACH (existing, cmap_node, &dns_cache_) { + if (existing->delete) { + cmap_remove(&dns_cache_, &existing->cmap_node, + uuid_hash(&existing->uuid)); + ovsrcu_postpone(dns_data_destroy, existing); } } - ovs_mutex_unlock(&dns_cache_mutex); } void ovn_dns_update_cache(const struct sbrec_dns_table *dns_table) { - ovs_mutex_lock(&dns_cache_mutex); - const struct sbrec_dns *sbrec_dns; + struct dns_data *existing; + SBREC_DNS_TABLE_FOR_EACH_TRACKED (sbrec_dns, dns_table) { const struct uuid *uuid = &sbrec_dns->header_.uuid; - struct dns_data *dns_data = dns_data_find(uuid); - if (sbrec_dns_is_deleted(sbrec_dns) && dns_data) { - hmap_remove(&dns_cache_, &dns_data->hmap_node); - dns_data_destroy(dns_data); + existing = dns_data_find(uuid, &dns_cache_); + if (sbrec_dns_is_deleted(sbrec_dns) && existing) { + cmap_remove(&dns_cache_, &existing->cmap_node, + uuid_hash(&existing->uuid)); + ovsrcu_postpone(dns_data_destroy, existing); } else { - update_cache_with_dns_rec(sbrec_dns, dns_data, uuid, &dns_cache_); + update_cache_with_dns_rec(sbrec_dns, existing, uuid, + &dns_cache_); } } - - ovs_mutex_unlock(&dns_cache_mutex); } const char * ovn_dns_lookup(const char *query_name, uint64_t dp_key, bool *ovn_owned) { - ovs_mutex_lock(&dns_cache_mutex); + const char *answer_data = NULL; + struct dns_data *dns_data; *ovn_owned = false; - struct dns_data *dns_data; - const char *answer_data = NULL; - HMAP_FOR_EACH (dns_data, hmap_node, &dns_cache_) { + + CMAP_FOR_EACH (dns_data, cmap_node, &dns_cache_) { for (size_t i = 0; i < dns_data->n_dps; i++) { if (dns_data->dps[i] == dp_key) { /* DNS records in SBDB are stored in lowercase. Convert to @@ -167,8 +141,6 @@ ovn_dns_lookup(const char *query_name, uint64_t dp_key, bool *ovn_owned) } } - ovs_mutex_unlock(&dns_cache_mutex); - return answer_data; } @@ -176,40 +148,35 @@ ovn_dns_lookup(const char *query_name, uint64_t dp_key, bool *ovn_owned) /* Static functions. */ static void update_cache_with_dns_rec(const struct sbrec_dns *sbrec_dns, - struct dns_data *dns_data, + struct dns_data *existing, const struct uuid *uuid, - struct hmap *dns_cache) + struct cmap *dns_cache) { - if (!dns_data) { - dns_data = dns_data_alloc(*uuid); - hmap_insert(dns_cache, &dns_data->hmap_node, uuid_hash(uuid)); - } else { - free(dns_data->dps); - } - - if (!smap_equal(&dns_data->records, &sbrec_dns->records)) { - smap_destroy(&dns_data->records); - smap_clone(&dns_data->records, &sbrec_dns->records); - } - - if (!smap_equal(&dns_data->options, &sbrec_dns->options)) { - smap_destroy(&dns_data->options); - smap_clone(&dns_data->options, &sbrec_dns->options); - } + struct dns_data *dns_data = dns_data_alloc(*uuid); + smap_clone(&dns_data->records, &sbrec_dns->records); + smap_clone(&dns_data->options, &sbrec_dns->options); dns_data->n_dps = sbrec_dns->n_datapaths; dns_data->dps = xcalloc(dns_data->n_dps, sizeof(uint64_t)); for (size_t i = 0; i < sbrec_dns->n_datapaths; i++) { dns_data->dps[i] = sbrec_dns->datapaths[i]->tunnel_key; } + + if (!existing) { + cmap_insert(dns_cache, &dns_data->cmap_node, uuid_hash(uuid)); + } else { + cmap_replace(dns_cache, &existing->cmap_node, &dns_data->cmap_node, + uuid_hash(uuid)); + ovsrcu_postpone(dns_data_destroy, existing); + } } static struct dns_data * -dns_data_find(const struct uuid *uuid) +dns_data_find(const struct uuid *uuid, const struct cmap *dns_cache) { struct dns_data *dns_data; size_t hash = uuid_hash(uuid); - HMAP_FOR_EACH_WITH_HASH (dns_data, hmap_node, hash, &dns_cache_) { + CMAP_FOR_EACH_WITH_HASH (dns_data, cmap_node, hash, dns_cache) { if (uuid_equals(&dns_data->uuid, uuid)) { return dns_data; } @@ -240,3 +207,12 @@ dns_data_destroy(struct dns_data *dns_data) free(dns_data->dps); free(dns_data); } + +static void +destroy_dns_cache(struct cmap *dns_cache) +{ + struct dns_data *dns_data; + CMAP_FOR_EACH (dns_data, cmap_node, dns_cache) { + ovsrcu_postpone(dns_data_destroy, dns_data); + } +} diff --git a/controller/pinctrl.c b/controller/pinctrl.c index 9bdfb6d901..2c2770241b 100644 --- a/controller/pinctrl.c +++ b/controller/pinctrl.c @@ -3884,6 +3884,8 @@ pinctrl_handler(void *arg_) static long long int send_prefixd_time = LLONG_MAX; while (!latch_is_set(&pctrl->pinctrl_thread_exit)) { + ovsrcu_quiesce_end(); + long long int bfd_time = LLONG_MAX; bool lock_failed = false; @@ -3957,6 +3959,8 @@ pinctrl_handler(void *arg_) latch_wait(&pctrl->pinctrl_thread_exit); } + + ovsrcu_quiesce_start(); poll_block(); }