diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index a4d44138c2a86..04960dc6228ff 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -42,6 +42,8 @@ static inline struct netns_ipvs *net_ipvs(struct net* net) /* Connections' size value needed by ip_vs_ctl.c */ extern int ip_vs_conn_tab_size; +extern struct mutex __ip_vs_mutex; + struct ip_vs_iphdr { int hdr_flags; /* ipvs flags */ __u32 off; /* Where IP or IPv4 header starts */ @@ -365,7 +367,7 @@ struct ip_vs_cpu_stats { /* IPVS statistics objects */ struct ip_vs_estimator { - struct list_head list; + struct hlist_node list; u64 last_inbytes; u64 last_outbytes; @@ -378,6 +380,10 @@ struct ip_vs_estimator { u64 outpps; u64 inbps; u64 outbps; + + s32 ktid:16, /* kthread ID, -1=temp list */ + ktrow:8, /* row/tick ID for kthread */ + ktcid:8; /* chain ID for kthread tick */ }; /* @@ -415,6 +421,66 @@ struct ip_vs_stats *ip_vs_stats_alloc(void); void ip_vs_stats_release(struct ip_vs_stats *stats); void ip_vs_stats_free(struct ip_vs_stats *stats); +/* Process estimators in multiple timer ticks (20/50/100, see ktrow) */ +#define IPVS_EST_NTICKS 50 +/* Estimation uses a 2-second period containing ticks (in jiffies) */ +#define IPVS_EST_TICK ((2 * HZ) / IPVS_EST_NTICKS) + +/* Limit of CPU load per kthread (8 for 12.5%), ratio of CPU capacity (1/C). + * Value of 4 and above ensures kthreads will take work without exceeding + * the CPU capacity under different circumstances. + */ +#define IPVS_EST_LOAD_DIVISOR 8 + +/* Kthreads should not have work that exceeds the CPU load above 50% */ +#define IPVS_EST_CPU_KTHREADS (IPVS_EST_LOAD_DIVISOR / 2) + +/* Desired number of chains per timer tick (chain load factor in 100us units), + * 48=4.8ms of 40ms tick (12% CPU usage): + * 2 sec * 1000 ms in sec * 10 (100us in ms) / 8 (12.5%) / 50 + */ +#define IPVS_EST_CHAIN_FACTOR \ + ALIGN_DOWN(2 * 1000 * 10 / IPVS_EST_LOAD_DIVISOR / IPVS_EST_NTICKS, 8) + +/* Compiled number of chains per tick + * The defines should match cond_resched_rcu + */ +#if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU) +#define IPVS_EST_TICK_CHAINS IPVS_EST_CHAIN_FACTOR +#else +#define IPVS_EST_TICK_CHAINS 1 +#endif + +#if IPVS_EST_NTICKS > 127 +#error Too many timer ticks for ktrow +#endif + +/* Multiple chains processed in same tick */ +struct ip_vs_est_tick_data { + struct hlist_head chains[IPVS_EST_TICK_CHAINS]; + DECLARE_BITMAP(present, IPVS_EST_TICK_CHAINS); + DECLARE_BITMAP(full, IPVS_EST_TICK_CHAINS); + int chain_len[IPVS_EST_TICK_CHAINS]; +}; + +/* Context for estimation kthread */ +struct ip_vs_est_kt_data { + struct netns_ipvs *ipvs; + struct task_struct *task; /* task if running */ + struct ip_vs_est_tick_data __rcu *ticks[IPVS_EST_NTICKS]; + DECLARE_BITMAP(avail, IPVS_EST_NTICKS); /* tick has space for ests */ + unsigned long est_timer; /* estimation timer (jiffies) */ + struct ip_vs_stats *calc_stats; /* Used for calculation */ + int tick_len[IPVS_EST_NTICKS]; /* est count */ + int id; /* ktid per netns */ + int chain_max; /* max ests per tick chain */ + int tick_max; /* max ests per tick */ + int est_count; /* attached ests to kthread */ + int est_max_count; /* max ests per kthread */ + int add_row; /* row for new ests */ + int est_row; /* estimated row */ +}; + struct dst_entry; struct iphdr; struct ip_vs_conn; @@ -953,9 +1019,17 @@ struct netns_ipvs { struct ctl_table_header *lblcr_ctl_header; struct ctl_table *lblcr_ctl_table; /* ip_vs_est */ - struct list_head est_list; /* estimator list */ - spinlock_t est_lock; - struct timer_list est_timer; /* Estimation timer */ + struct delayed_work est_reload_work;/* Reload kthread tasks */ + struct mutex est_mutex; /* protect kthread tasks */ + struct hlist_head est_temp_list; /* Ests during calc phase */ + struct ip_vs_est_kt_data **est_kt_arr; /* Array of kthread data ptrs */ + unsigned long est_max_threads;/* Hard limit of kthreads */ + int est_calc_phase; /* Calculation phase */ + int est_chain_max; /* Calculated chain_max */ + int est_kt_count; /* Allocated ptrs */ + int est_add_ktid; /* ktid where to add ests */ + atomic_t est_genid; /* kthreads reload genid */ + atomic_t est_genid_done; /* applied genid */ /* ip_vs_sync */ spinlock_t sync_lock; struct ipvs_master_sync_state *ms; @@ -1486,10 +1560,14 @@ int stop_sync_thread(struct netns_ipvs *ipvs, int state); void ip_vs_sync_conn(struct netns_ipvs *ipvs, struct ip_vs_conn *cp, int pkts); /* IPVS rate estimator prototypes (from ip_vs_est.c) */ -void ip_vs_start_estimator(struct netns_ipvs *ipvs, struct ip_vs_stats *stats); +int ip_vs_start_estimator(struct netns_ipvs *ipvs, struct ip_vs_stats *stats); void ip_vs_stop_estimator(struct netns_ipvs *ipvs, struct ip_vs_stats *stats); void ip_vs_zero_estimator(struct ip_vs_stats *stats); void ip_vs_read_estimator(struct ip_vs_kstats *dst, struct ip_vs_stats *stats); +void ip_vs_est_reload_start(struct netns_ipvs *ipvs); +int ip_vs_est_kthread_start(struct netns_ipvs *ipvs, + struct ip_vs_est_kt_data *kd); +void ip_vs_est_kthread_stop(struct ip_vs_est_kt_data *kd); /* Various IPVS packet transmitters (from ip_vs_xmit.c) */ int ip_vs_null_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 5f9cc2e7ba71b..c41a5392edc93 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -49,8 +49,7 @@ MODULE_ALIAS_GENL_FAMILY(IPVS_GENL_NAME); -/* semaphore for IPVS sockopts. And, [gs]etsockopt may sleep. */ -static DEFINE_MUTEX(__ip_vs_mutex); +DEFINE_MUTEX(__ip_vs_mutex); /* Serialize configuration with sockopt/netlink */ /* sysctl variables */ @@ -241,6 +240,47 @@ static void defense_work_handler(struct work_struct *work) } #endif +static void est_reload_work_handler(struct work_struct *work) +{ + struct netns_ipvs *ipvs = + container_of(work, struct netns_ipvs, est_reload_work.work); + int genid_done = atomic_read(&ipvs->est_genid_done); + unsigned long delay = HZ / 10; /* repeat startups after failure */ + bool repeat = false; + int genid; + int id; + + mutex_lock(&ipvs->est_mutex); + genid = atomic_read(&ipvs->est_genid); + for (id = 0; id < ipvs->est_kt_count; id++) { + struct ip_vs_est_kt_data *kd = ipvs->est_kt_arr[id]; + + /* netns clean up started, abort delayed work */ + if (!ipvs->enable) + goto unlock; + if (!kd) + continue; + /* New config ? Stop kthread tasks */ + if (genid != genid_done) + ip_vs_est_kthread_stop(kd); + if (!kd->task) { + /* Do not start kthreads above 0 in calc phase */ + if ((!id || !ipvs->est_calc_phase) && + ip_vs_est_kthread_start(ipvs, kd) < 0) + repeat = true; + } + } + + atomic_set(&ipvs->est_genid_done, genid); + + if (repeat) + queue_delayed_work(system_long_wq, &ipvs->est_reload_work, + delay); + +unlock: + mutex_unlock(&ipvs->est_mutex); +} + int ip_vs_use_count_inc(void) { @@ -831,7 +871,7 @@ ip_vs_copy_stats(struct ip_vs_kstats *dst, struct ip_vs_stats *src) { #define IP_VS_SHOW_STATS_COUNTER(c) dst->c = src->kstats.c - src->kstats0.c - spin_lock_bh(&src->lock); + spin_lock(&src->lock); IP_VS_SHOW_STATS_COUNTER(conns); IP_VS_SHOW_STATS_COUNTER(inpkts); @@ -841,7 +881,7 @@ ip_vs_copy_stats(struct ip_vs_kstats *dst, struct ip_vs_stats *src) ip_vs_read_estimator(dst, src); - spin_unlock_bh(&src->lock); + spin_unlock(&src->lock); } static void @@ -862,7 +902,7 @@ ip_vs_export_stats_user(struct ip_vs_stats_user *dst, struct ip_vs_kstats *src) static void ip_vs_zero_stats(struct ip_vs_stats *stats) { - spin_lock_bh(&stats->lock); + spin_lock(&stats->lock); /* get current counters as zero point, rates are zeroed */ @@ -876,7 +916,7 @@ ip_vs_zero_stats(struct ip_vs_stats *stats) ip_vs_zero_estimator(stats); - spin_unlock_bh(&stats->lock); + spin_unlock(&stats->lock); } /* Allocate fields after kzalloc */ @@ -998,7 +1038,6 @@ __ip_vs_update_dest(struct ip_vs_service *svc, struct ip_vs_dest *dest, spin_unlock_bh(&dest->dst_lock); if (add) { - ip_vs_start_estimator(svc->ipvs, &dest->stats); list_add_rcu(&dest->n_list, &svc->destinations); svc->num_dests++; sched = rcu_dereference_protected(svc->scheduler, 1); @@ -1051,6 +1090,10 @@ ip_vs_new_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest) if (ret < 0) goto err_alloc; + ret = ip_vs_start_estimator(svc->ipvs, &dest->stats); + if (ret < 0) + goto err_stats; + dest->af = udest->af; dest->protocol = svc->protocol; dest->vaddr = svc->addr; @@ -1071,6 +1114,9 @@ ip_vs_new_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest) LeaveFunction(2); return 0; +err_stats: + ip_vs_stats_release(&dest->stats); + err_alloc: kfree(dest); return ret; @@ -1135,14 +1181,18 @@ ip_vs_add_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest) IP_VS_DBG_ADDR(svc->af, &dest->vaddr), ntohs(dest->vport)); + ret = ip_vs_start_estimator(svc->ipvs, &dest->stats); + if (ret < 0) + goto err; __ip_vs_update_dest(svc, dest, udest, 1); - ret = 0; } else { /* * Allocate and initialize the dest structure */ ret = ip_vs_new_dest(svc, udest); } + +err: LeaveFunction(2); return ret; @@ -1420,6 +1470,10 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u, sched = NULL; } + ret = ip_vs_start_estimator(ipvs, &svc->stats); + if (ret < 0) + goto out_err; + /* Bind the ct retriever */ RCU_INIT_POINTER(svc->pe, pe); pe = NULL; @@ -1432,8 +1486,6 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u, if (svc->pe && svc->pe->conn_out) atomic_inc(&ipvs->conn_out_counter); - ip_vs_start_estimator(ipvs, &svc->stats); - /* Count only IPv4 services for old get/setsockopt interface */ if (svc->af == AF_INET) ipvs->num_services++; @@ -1444,8 +1496,15 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u, ip_vs_svc_hash(svc); *svc_p = svc; - /* Now there is a service - full throttle */ - ipvs->enable = 1; + + if (!ipvs->enable) { + /* Now there is a service - full throttle */ + ipvs->enable = 1; + + /* Start estimation for first time */ + ip_vs_est_reload_start(ipvs); + } + return 0; @@ -4065,13 +4124,16 @@ static void ip_vs_genl_unregister(void) static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs) { struct net *net = ipvs->net; - int idx; struct ctl_table *tbl; + int idx, ret; atomic_set(&ipvs->dropentry, 0); spin_lock_init(&ipvs->dropentry_lock); spin_lock_init(&ipvs->droppacket_lock); spin_lock_init(&ipvs->securetcp_lock); + INIT_DELAYED_WORK(&ipvs->defense_work, defense_work_handler); + INIT_DELAYED_WORK(&ipvs->expire_nodest_conn_work, + expire_nodest_conn_handler); if (!net_eq(net, &init_net)) { tbl = kmemdup(vs_vars, sizeof(vs_vars), GFP_KERNEL); @@ -4139,24 +4201,27 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs) tbl[idx++].mode = 0444; #endif + ret = -ENOMEM; ipvs->sysctl_hdr = register_net_sysctl(net, "net/ipv4/vs", tbl); - if (ipvs->sysctl_hdr == NULL) { - if (!net_eq(net, &init_net)) - kfree(tbl); - return -ENOMEM; - } + if (!ipvs->sysctl_hdr) + goto err; ipvs->sysctl_tbl = tbl; + + ret = ip_vs_start_estimator(ipvs, &ipvs->tot_stats->s); + if (ret < 0) + goto err; + /* Schedule defense work */ - INIT_DELAYED_WORK(&ipvs->defense_work, defense_work_handler); queue_delayed_work(system_long_wq, &ipvs->defense_work, DEFENSE_TIMER_PERIOD); - /* Init delayed work for expiring no dest conn */ - INIT_DELAYED_WORK(&ipvs->expire_nodest_conn_work, - expire_nodest_conn_handler); - - ip_vs_start_estimator(ipvs, &ipvs->tot_stats->s); return 0; + +err: + unregister_net_sysctl_table(ipvs->sysctl_hdr); + if (!net_eq(net, &init_net)) + kfree(tbl); + return ret; } static void __net_exit ip_vs_control_net_cleanup_sysctl(struct netns_ipvs *ipvs) @@ -4189,6 +4254,7 @@ static struct notifier_block ip_vs_dst_notifier = { int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs) { + int ret = -ENOMEM; int idx; /* Initialize rs_table */ @@ -4202,10 +4268,12 @@ int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs) atomic_set(&ipvs->nullsvc_counter, 0); atomic_set(&ipvs->conn_out_counter, 0); + INIT_DELAYED_WORK(&ipvs->est_reload_work, est_reload_work_handler); + /* procfs stats */ ipvs->tot_stats = kzalloc(sizeof(*ipvs->tot_stats), GFP_KERNEL); if (!ipvs->tot_stats) - return -ENOMEM; + goto out; if (ip_vs_stats_init_alloc(&ipvs->tot_stats->s) < 0) goto err_tot_stats; @@ -4222,7 +4290,8 @@ int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs) goto err_percpu; #endif - if (ip_vs_control_net_init_sysctl(ipvs)) + ret = ip_vs_control_net_init_sysctl(ipvs); + if (ret < 0) goto err; return 0; @@ -4243,13 +4312,16 @@ int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs) err_tot_stats: kfree(ipvs->tot_stats); - return -ENOMEM; + +out: + return ret; } void __net_exit ip_vs_control_net_cleanup(struct netns_ipvs *ipvs) { ip_vs_trash_cleanup(ipvs); ip_vs_control_net_cleanup_sysctl(ipvs); + cancel_delayed_work_sync(&ipvs->est_reload_work); #ifdef CONFIG_PROC_FS remove_proc_entry("ip_vs_stats_percpu", ipvs->net->proc_net); remove_proc_entry("ip_vs_stats", ipvs->net->proc_net); diff --git a/net/netfilter/ipvs/ip_vs_est.c b/net/netfilter/ipvs/ip_vs_est.c index f53150d82a92d..2fb6c097437cc 100644 --- a/net/netfilter/ipvs/ip_vs_est.c +++ b/net/netfilter/ipvs/ip_vs_est.c @@ -30,9 +30,6 @@ long interval, it is easy to implement a user level daemon which periodically reads those statistical counters and measure rate. - Currently, the measurement is activated by slow timer handler. Hope - this measurement will not introduce too much load. - We measure rate during the last 8 seconds every 2 seconds: avgrate = avgrate*(1-W) + rate*W @@ -47,68 +44,76 @@ to 32-bit values for conns, packets, bps, cps and pps. * A lot of code is taken from net/core/gen_estimator.c - */ - -/* - * Make a summary from each cpu + KEY POINTS: + - cpustats counters are updated per-cpu in SoftIRQ context with BH disabled + - kthreads read the cpustats to update the estimators (svcs, dests, total) + - the states of estimators can be read (get stats) or modified (zero stats) + from processes + + KTHREADS: + - estimators are added initially to est_temp_list and later kthread 0 + distributes them to one or many kthreads for estimation + - kthread contexts are created and attached to array + - the kthread tasks are started when first service is added, before that + the total stats are not estimated + - the kthread context holds lists with estimators (chains) which are + processed every 2 seconds + - as estimators can be added dynamically and in bursts, we try to spread + them to multiple chains which are estimated at different time + - on start, kthread 0 enters calculation phase to determine the chain limits + and the limit of estimators per kthread + - est_add_ktid: ktid where to add new ests, can point to empty slot where + we should add kt data */ -static void ip_vs_read_cpu_stats(struct ip_vs_kstats *sum, - struct ip_vs_cpu_stats __percpu *stats) -{ - int i; - bool add = false; - - for_each_possible_cpu(i) { - struct ip_vs_cpu_stats *s = per_cpu_ptr(stats, i); - unsigned int start; - u64 conns, inpkts, outpkts, inbytes, outbytes; - if (add) { - do { - start = u64_stats_fetch_begin(&s->syncp); - conns = u64_stats_read(&s->cnt.conns); - inpkts = u64_stats_read(&s->cnt.inpkts); - outpkts = u64_stats_read(&s->cnt.outpkts); - inbytes = u64_stats_read(&s->cnt.inbytes); - outbytes = u64_stats_read(&s->cnt.outbytes); - } while (u64_stats_fetch_retry(&s->syncp, start)); - sum->conns += conns; - sum->inpkts += inpkts; - sum->outpkts += outpkts; - sum->inbytes += inbytes; - sum->outbytes += outbytes; - } else { - add = true; - do { - start = u64_stats_fetch_begin(&s->syncp); - sum->conns = u64_stats_read(&s->cnt.conns); - sum->inpkts = u64_stats_read(&s->cnt.inpkts); - sum->outpkts = u64_stats_read(&s->cnt.outpkts); - sum->inbytes = u64_stats_read(&s->cnt.inbytes); - sum->outbytes = u64_stats_read(&s->cnt.outbytes); - } while (u64_stats_fetch_retry(&s->syncp, start)); - } - } -} +static struct lock_class_key __ipvs_est_key; +static void ip_vs_est_calc_phase(struct netns_ipvs *ipvs); +static void ip_vs_est_drain_temp_list(struct netns_ipvs *ipvs); -static void estimation_timer(struct timer_list *t) +static void ip_vs_chain_estimation(struct hlist_head *chain) { struct ip_vs_estimator *e; + struct ip_vs_cpu_stats *c; struct ip_vs_stats *s; u64 rate; - struct netns_ipvs *ipvs = from_timer(ipvs, t, est_timer); - if (!sysctl_run_estimation(ipvs)) - goto skip; + hlist_for_each_entry_rcu(e, chain, list) { + u64 conns, inpkts, outpkts, inbytes, outbytes; + u64 kconns = 0, kinpkts = 0, koutpkts = 0; + u64 kinbytes = 0, koutbytes = 0; + unsigned int start; + int i; + + if (kthread_should_stop()) + break; - spin_lock(&ipvs->est_lock); - list_for_each_entry(e, &ipvs->est_list, list) { s = container_of(e, struct ip_vs_stats, est); + for_each_possible_cpu(i) { + c = per_cpu_ptr(s->cpustats, i); + do { + start = u64_stats_fetch_begin(&c->syncp); + conns = u64_stats_read(&c->cnt.conns); + inpkts = u64_stats_read(&c->cnt.inpkts); + outpkts = u64_stats_read(&c->cnt.outpkts); + inbytes = u64_stats_read(&c->cnt.inbytes); + outbytes = u64_stats_read(&c->cnt.outbytes); + } while (u64_stats_fetch_retry(&c->syncp, start)); + kconns += conns; + kinpkts += inpkts; + koutpkts += outpkts; + kinbytes += inbytes; + koutbytes += outbytes; + } spin_lock(&s->lock); - ip_vs_read_cpu_stats(&s->kstats, s->cpustats); + + s->kstats.conns = kconns; + s->kstats.inpkts = kinpkts; + s->kstats.outpkts = koutpkts; + s->kstats.inbytes = kinbytes; + s->kstats.outbytes = koutbytes; /* scaled by 2^10, but divided 2 seconds */ rate = (s->kstats.conns - e->last_conns) << 9; @@ -133,30 +138,754 @@ static void estimation_timer(struct timer_list *t) e->outbps += ((s64)rate - (s64)e->outbps) >> 2; spin_unlock(&s->lock); } - spin_unlock(&ipvs->est_lock); +} -skip: - mod_timer(&ipvs->est_timer, jiffies + 2*HZ); +static void ip_vs_tick_estimation(struct ip_vs_est_kt_data *kd, int row) +{ + struct ip_vs_est_tick_data *td; + int cid; + + rcu_read_lock(); + td = rcu_dereference(kd->ticks[row]); + if (!td) + goto out; + for_each_set_bit(cid, td->present, IPVS_EST_TICK_CHAINS) { + if (kthread_should_stop()) + break; + ip_vs_chain_estimation(&td->chains[cid]); + cond_resched_rcu(); + td = rcu_dereference(kd->ticks[row]); + if (!td) + break; + } + +out: + rcu_read_unlock(); } -void ip_vs_start_estimator(struct netns_ipvs *ipvs, struct ip_vs_stats *stats) +static int ip_vs_estimation_kthread(void *data) { - struct ip_vs_estimator *est = &stats->est; + struct ip_vs_est_kt_data *kd = data; + struct netns_ipvs *ipvs = kd->ipvs; + int row = kd->est_row; + unsigned long now; + int id = kd->id; + long gap; + + if (id > 0) { + if (!ipvs->est_chain_max) + return 0; + } else { + if (!ipvs->est_chain_max) { + ipvs->est_calc_phase = 1; + /* commit est_calc_phase before reading est_genid */ + smp_mb(); + } + + /* kthread 0 will handle the calc phase */ + if (ipvs->est_calc_phase) + ip_vs_est_calc_phase(ipvs); + } + + while (1) { + if (!id && !hlist_empty(&ipvs->est_temp_list)) + ip_vs_est_drain_temp_list(ipvs); + set_current_state(TASK_IDLE); + if (kthread_should_stop()) + break; + + /* before estimation, check if we should sleep */ + now = jiffies; + gap = kd->est_timer - now; + if (gap > 0) { + if (gap > IPVS_EST_TICK) { + kd->est_timer = now - IPVS_EST_TICK; + gap = IPVS_EST_TICK; + } + schedule_timeout(gap); + } else { + __set_current_state(TASK_RUNNING); + if (gap < -8 * IPVS_EST_TICK) + kd->est_timer = now; + } + + if (sysctl_run_estimation(ipvs) && kd->tick_len[row]) + ip_vs_tick_estimation(kd, row); + + row++; + if (row >= IPVS_EST_NTICKS) + row = 0; + WRITE_ONCE(kd->est_row, row); + kd->est_timer += IPVS_EST_TICK; + } + __set_current_state(TASK_RUNNING); + + return 0; +} + +/* Schedule stop/start for kthread tasks */ +void ip_vs_est_reload_start(struct netns_ipvs *ipvs) +{ + /* Ignore reloads before first service is added */ + if (!ipvs->enable) + return; + /* Bump the kthread configuration genid */ + atomic_inc(&ipvs->est_genid); + queue_delayed_work(system_long_wq, &ipvs->est_reload_work, 0); +} + +/* Start kthread task with current configuration */ +int ip_vs_est_kthread_start(struct netns_ipvs *ipvs, + struct ip_vs_est_kt_data *kd) +{ + unsigned long now; + int ret = 0; + long gap; + + lockdep_assert_held(&ipvs->est_mutex); + + if (kd->task) + goto out; + now = jiffies; + gap = kd->est_timer - now; + /* Sync est_timer if task is starting later */ + if (abs(gap) > 4 * IPVS_EST_TICK) + kd->est_timer = now; + kd->task = kthread_create(ip_vs_estimation_kthread, kd, "ipvs-e:%d:%d", + ipvs->gen, kd->id); + if (IS_ERR(kd->task)) { + ret = PTR_ERR(kd->task); + kd->task = NULL; + goto out; + } + + pr_info("starting estimator thread %d...\n", kd->id); + wake_up_process(kd->task); + +out: + return ret; +} + +void ip_vs_est_kthread_stop(struct ip_vs_est_kt_data *kd) +{ + if (kd->task) { + pr_info("stopping estimator thread %d...\n", kd->id); + kthread_stop(kd->task); + kd->task = NULL; + } +} + +/* Apply parameters to kthread */ +static void ip_vs_est_set_params(struct netns_ipvs *ipvs, + struct ip_vs_est_kt_data *kd) +{ + kd->chain_max = ipvs->est_chain_max; + /* We are using single chain on RCU preemption */ + if (IPVS_EST_TICK_CHAINS == 1) + kd->chain_max *= IPVS_EST_CHAIN_FACTOR; + kd->tick_max = IPVS_EST_TICK_CHAINS * kd->chain_max; + kd->est_max_count = IPVS_EST_NTICKS * kd->tick_max; +} + +/* Create and start estimation kthread in a free or new array slot */ +static int ip_vs_est_add_kthread(struct netns_ipvs *ipvs) +{ + struct ip_vs_est_kt_data *kd = NULL; + int id = ipvs->est_kt_count; + int ret = -ENOMEM; + void *arr = NULL; + int i; + + if ((unsigned long)ipvs->est_kt_count >= ipvs->est_max_threads && + ipvs->enable && ipvs->est_max_threads) + return -EINVAL; + + mutex_lock(&ipvs->est_mutex); + + for (i = 0; i < id; i++) { + if (!ipvs->est_kt_arr[i]) + break; + } + if (i >= id) { + arr = krealloc_array(ipvs->est_kt_arr, id + 1, + sizeof(struct ip_vs_est_kt_data *), + GFP_KERNEL); + if (!arr) + goto out; + ipvs->est_kt_arr = arr; + } else { + id = i; + } + + kd = kzalloc(sizeof(*kd), GFP_KERNEL); + if (!kd) + goto out; + kd->ipvs = ipvs; + bitmap_fill(kd->avail, IPVS_EST_NTICKS); + kd->est_timer = jiffies; + kd->id = id; + ip_vs_est_set_params(ipvs, kd); + + /* Pre-allocate stats used in calc phase */ + if (!id && !kd->calc_stats) { + kd->calc_stats = ip_vs_stats_alloc(); + if (!kd->calc_stats) + goto out; + } + + /* Start kthread tasks only when services are present */ + if (ipvs->enable) { + ret = ip_vs_est_kthread_start(ipvs, kd); + if (ret < 0) + goto out; + } + + if (arr) + ipvs->est_kt_count++; + ipvs->est_kt_arr[id] = kd; + kd = NULL; + /* Use most recent kthread for new ests */ + ipvs->est_add_ktid = id; + ret = 0; + +out: + mutex_unlock(&ipvs->est_mutex); + if (kd) { + ip_vs_stats_free(kd->calc_stats); + kfree(kd); + } + + return ret; +} + +/* Select ktid where to add new ests: available, unused or new slot */ +static void ip_vs_est_update_ktid(struct netns_ipvs *ipvs) +{ + int ktid, best = ipvs->est_kt_count; + struct ip_vs_est_kt_data *kd; + + for (ktid = 0; ktid < ipvs->est_kt_count; ktid++) { + kd = ipvs->est_kt_arr[ktid]; + if (kd) { + if (kd->est_count < kd->est_max_count) { + best = ktid; + break; + } + } else if (ktid < best) { + best = ktid; + } + } + ipvs->est_add_ktid = best; +} + +/* Add estimator to current kthread (est_add_ktid) */ +static int ip_vs_enqueue_estimator(struct netns_ipvs *ipvs, + struct ip_vs_estimator *est) +{ + struct ip_vs_est_kt_data *kd = NULL; + struct ip_vs_est_tick_data *td; + int ktid, row, crow, cid, ret; + int delay = est->ktrow; + + BUILD_BUG_ON_MSG(IPVS_EST_TICK_CHAINS > 127, + "Too many chains for ktcid"); + + if (ipvs->est_add_ktid < ipvs->est_kt_count) { + kd = ipvs->est_kt_arr[ipvs->est_add_ktid]; + if (kd) + goto add_est; + } + + ret = ip_vs_est_add_kthread(ipvs); + if (ret < 0) + goto out; + kd = ipvs->est_kt_arr[ipvs->est_add_ktid]; + +add_est: + ktid = kd->id; + /* For small number of estimators prefer to use few ticks, + * otherwise try to add into the last estimated row. + * est_row and add_row point after the row we should use + */ + if (kd->est_count >= 2 * kd->tick_max || delay < IPVS_EST_NTICKS - 1) + crow = READ_ONCE(kd->est_row); + else + crow = kd->add_row; + crow += delay; + if (crow >= IPVS_EST_NTICKS) + crow -= IPVS_EST_NTICKS; + /* Assume initial delay ? */ + if (delay >= IPVS_EST_NTICKS - 1) { + /* Preserve initial delay or decrease it if no space in tick */ + row = crow; + if (crow < IPVS_EST_NTICKS - 1) { + crow++; + row = find_last_bit(kd->avail, crow); + } + if (row >= crow) + row = find_last_bit(kd->avail, IPVS_EST_NTICKS); + } else { + /* Preserve delay or increase it if no space in tick */ + row = IPVS_EST_NTICKS; + if (crow > 0) + row = find_next_bit(kd->avail, IPVS_EST_NTICKS, crow); + if (row >= IPVS_EST_NTICKS) + row = find_first_bit(kd->avail, IPVS_EST_NTICKS); + } + + td = rcu_dereference_protected(kd->ticks[row], 1); + if (!td) { + td = kzalloc(sizeof(*td), GFP_KERNEL); + if (!td) { + ret = -ENOMEM; + goto out; + } + rcu_assign_pointer(kd->ticks[row], td); + } + + cid = find_first_zero_bit(td->full, IPVS_EST_TICK_CHAINS); + + kd->est_count++; + kd->tick_len[row]++; + if (!td->chain_len[cid]) + __set_bit(cid, td->present); + td->chain_len[cid]++; + est->ktid = ktid; + est->ktrow = row; + est->ktcid = cid; + hlist_add_head_rcu(&est->list, &td->chains[cid]); + + if (td->chain_len[cid] >= kd->chain_max) { + __set_bit(cid, td->full); + if (kd->tick_len[row] >= kd->tick_max) + __clear_bit(row, kd->avail); + } + + /* Update est_add_ktid to point to first available/empty kt slot */ + if (kd->est_count == kd->est_max_count) + ip_vs_est_update_ktid(ipvs); + + ret = 0; + +out: + return ret; +} - INIT_LIST_HEAD(&est->list); +/* Start estimation for stats */ +int ip_vs_start_estimator(struct netns_ipvs *ipvs, struct ip_vs_stats *stats) +{ + struct ip_vs_estimator *est = &stats->est; + int ret; + + if (!ipvs->est_max_threads && ipvs->enable) + ipvs->est_max_threads = IPVS_EST_CPU_KTHREADS * + num_possible_cpus(); + + est->ktid = -1; + est->ktrow = IPVS_EST_NTICKS - 1; /* Initial delay */ + + /* We prefer this code to be short, kthread 0 will requeue the + * estimator to available chain. If tasks are disabled, we + * will not allocate much memory, just for kt 0. + */ + ret = 0; + if (!ipvs->est_kt_count || !ipvs->est_kt_arr[0]) + ret = ip_vs_est_add_kthread(ipvs); + if (ret >= 0) + hlist_add_head(&est->list, &ipvs->est_temp_list); + else + INIT_HLIST_NODE(&est->list); + return ret; +} - spin_lock_bh(&ipvs->est_lock); - list_add(&est->list, &ipvs->est_list); - spin_unlock_bh(&ipvs->est_lock); +static void ip_vs_est_kthread_destroy(struct ip_vs_est_kt_data *kd) +{ + if (kd) { + if (kd->task) { + pr_info("stop unused estimator thread %d...\n", kd->id); + kthread_stop(kd->task); + } + ip_vs_stats_free(kd->calc_stats); + kfree(kd); + } } +/* Unlink estimator from chain */ void ip_vs_stop_estimator(struct netns_ipvs *ipvs, struct ip_vs_stats *stats) { struct ip_vs_estimator *est = &stats->est; + struct ip_vs_est_tick_data *td; + struct ip_vs_est_kt_data *kd; + int ktid = est->ktid; + int row = est->ktrow; + int cid = est->ktcid; + + /* Failed to add to chain ? */ + if (hlist_unhashed(&est->list)) + return; + + /* On return, estimator can be freed, dequeue it now */ + + /* In est_temp_list ? */ + if (ktid < 0) { + hlist_del(&est->list); + goto end_kt0; + } + + hlist_del_rcu(&est->list); + kd = ipvs->est_kt_arr[ktid]; + td = rcu_dereference_protected(kd->ticks[row], 1); + __clear_bit(cid, td->full); + td->chain_len[cid]--; + if (!td->chain_len[cid]) + __clear_bit(cid, td->present); + kd->tick_len[row]--; + __set_bit(row, kd->avail); + if (!kd->tick_len[row]) { + RCU_INIT_POINTER(kd->ticks[row], NULL); + kfree_rcu(td); + } + kd->est_count--; + if (kd->est_count) { + /* This kt slot can become available just now, prefer it */ + if (ktid < ipvs->est_add_ktid) + ipvs->est_add_ktid = ktid; + return; + } - spin_lock_bh(&ipvs->est_lock); - list_del(&est->list); - spin_unlock_bh(&ipvs->est_lock); + if (ktid > 0) { + mutex_lock(&ipvs->est_mutex); + ip_vs_est_kthread_destroy(kd); + ipvs->est_kt_arr[ktid] = NULL; + if (ktid == ipvs->est_kt_count - 1) { + ipvs->est_kt_count--; + while (ipvs->est_kt_count > 1 && + !ipvs->est_kt_arr[ipvs->est_kt_count - 1]) + ipvs->est_kt_count--; + } + mutex_unlock(&ipvs->est_mutex); + + /* This slot is now empty, prefer another available kt slot */ + if (ktid == ipvs->est_add_ktid) + ip_vs_est_update_ktid(ipvs); + } + +end_kt0: + /* kt 0 is freed after all other kthreads and chains are empty */ + if (ipvs->est_kt_count == 1 && hlist_empty(&ipvs->est_temp_list)) { + kd = ipvs->est_kt_arr[0]; + if (!kd || !kd->est_count) { + mutex_lock(&ipvs->est_mutex); + if (kd) { + ip_vs_est_kthread_destroy(kd); + ipvs->est_kt_arr[0] = NULL; + } + ipvs->est_kt_count--; + mutex_unlock(&ipvs->est_mutex); + ipvs->est_add_ktid = 0; + } + } +} + +/* Register all ests from est_temp_list to kthreads */ +static void ip_vs_est_drain_temp_list(struct netns_ipvs *ipvs) +{ + struct ip_vs_estimator *est; + + while (1) { + int max = 16; + + mutex_lock(&__ip_vs_mutex); + + while (max-- > 0) { + est = hlist_entry_safe(ipvs->est_temp_list.first, + struct ip_vs_estimator, list); + if (est) { + if (kthread_should_stop()) + goto unlock; + hlist_del_init(&est->list); + if (ip_vs_enqueue_estimator(ipvs, est) >= 0) + continue; + est->ktid = -1; + hlist_add_head(&est->list, + &ipvs->est_temp_list); + /* Abort, some entries will not be estimated + * until next attempt + */ + } + goto unlock; + } + mutex_unlock(&__ip_vs_mutex); + cond_resched(); + } + +unlock: + mutex_unlock(&__ip_vs_mutex); +} + +/* Calculate limits for all kthreads */ +static int ip_vs_est_calc_limits(struct netns_ipvs *ipvs, int *chain_max) +{ + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); + struct ip_vs_est_kt_data *kd; + struct hlist_head chain; + struct ip_vs_stats *s; + int cache_factor = 4; + int i, loops, ntest; + s32 min_est = 0; + ktime_t t1, t2; + s64 diff, val; + int max = 8; + int ret = 1; + + INIT_HLIST_HEAD(&chain); + mutex_lock(&__ip_vs_mutex); + kd = ipvs->est_kt_arr[0]; + mutex_unlock(&__ip_vs_mutex); + s = kd ? kd->calc_stats : NULL; + if (!s) + goto out; + hlist_add_head(&s->est.list, &chain); + + loops = 1; + /* Get best result from many tests */ + for (ntest = 0; ntest < 12; ntest++) { + if (!(ntest & 3)) { + /* Wait for cpufreq frequency transition */ + wait_event_idle_timeout(wq, kthread_should_stop(), + HZ / 50); + if (!ipvs->enable || kthread_should_stop()) + goto stop; + } + + local_bh_disable(); + rcu_read_lock(); + + /* Put stats in cache */ + ip_vs_chain_estimation(&chain); + + t1 = ktime_get(); + for (i = loops * cache_factor; i > 0; i--) + ip_vs_chain_estimation(&chain); + t2 = ktime_get(); + + rcu_read_unlock(); + local_bh_enable(); + + if (!ipvs->enable || kthread_should_stop()) + goto stop; + cond_resched(); + + diff = ktime_to_ns(ktime_sub(t2, t1)); + if (diff <= 1 * NSEC_PER_USEC) { + /* Do more loops on low time resolution */ + loops *= 2; + continue; + } + if (diff >= NSEC_PER_SEC) + continue; + val = diff; + do_div(val, loops); + if (!min_est || val < min_est) { + min_est = val; + /* goal: 95usec per chain */ + val = 95 * NSEC_PER_USEC; + if (val >= min_est) { + do_div(val, min_est); + max = (int)val; + } else { + max = 1; + } + } + } + +out: + if (s) + hlist_del_init(&s->est.list); + *chain_max = max; + return ret; + +stop: + ret = 0; + goto out; +} + +/* Calculate the parameters and apply them in context of kt #0 + * ECP: est_calc_phase + * ECM: est_chain_max + * ECP ECM Insert Chain enable Description + * --------------------------------------------------------------------------- + * 0 0 est_temp_list 0 create kt #0 context + * 0 0 est_temp_list 0->1 service added, start kthread #0 task + * 0->1 0 est_temp_list 1 kt task #0 started, enters calc phase + * 1 0 est_temp_list 1 kt #0: determine est_chain_max, + * stop tasks, move ests to est_temp_list + * and free kd for kthreads 1..last + * 1->0 0->N kt chains 1 ests can go to kthreads + * 0 N kt chains 1 drain est_temp_list, create new kthread + * contexts, start tasks, estimate + */ +static void ip_vs_est_calc_phase(struct netns_ipvs *ipvs) +{ + int genid = atomic_read(&ipvs->est_genid); + struct ip_vs_est_tick_data *td; + struct ip_vs_est_kt_data *kd; + struct ip_vs_estimator *est; + struct ip_vs_stats *stats; + int id, row, cid, delay; + bool last, last_td; + int chain_max; + int step; + + if (!ip_vs_est_calc_limits(ipvs, &chain_max)) + return; + + mutex_lock(&__ip_vs_mutex); + + /* Stop all other tasks, so that we can immediately move the + * estimators to est_temp_list without RCU grace period + */ + mutex_lock(&ipvs->est_mutex); + for (id = 1; id < ipvs->est_kt_count; id++) { + /* netns clean up started, abort */ + if (!ipvs->enable) + goto unlock2; + kd = ipvs->est_kt_arr[id]; + if (!kd) + continue; + ip_vs_est_kthread_stop(kd); + } + mutex_unlock(&ipvs->est_mutex); + + /* Move all estimators to est_temp_list but carefully, + * all estimators and kthread data can be released while + * we reschedule. Even for kthread 0. + */ + step = 0; + + /* Order entries in est_temp_list in ascending delay, so now + * walk delay(desc), id(desc), cid(asc) + */ + delay = IPVS_EST_NTICKS; + +next_delay: + delay--; + if (delay < 0) + goto end_dequeue; + +last_kt: + /* Destroy contexts backwards */ + id = ipvs->est_kt_count; + +next_kt: + if (!ipvs->enable || kthread_should_stop()) + goto unlock; + id--; + if (id < 0) + goto next_delay; + kd = ipvs->est_kt_arr[id]; + if (!kd) + goto next_kt; + /* kt 0 can exist with empty chains */ + if (!id && kd->est_count <= 1) + goto next_delay; + + row = kd->est_row + delay; + if (row >= IPVS_EST_NTICKS) + row -= IPVS_EST_NTICKS; + td = rcu_dereference_protected(kd->ticks[row], 1); + if (!td) + goto next_kt; + + cid = 0; + +walk_chain: + if (kthread_should_stop()) + goto unlock; + step++; + if (!(step & 63)) { + /* Give chance estimators to be added (to est_temp_list) + * and deleted (releasing kthread contexts) + */ + mutex_unlock(&__ip_vs_mutex); + cond_resched(); + mutex_lock(&__ip_vs_mutex); + + /* Current kt released ? */ + if (id >= ipvs->est_kt_count) + goto last_kt; + if (kd != ipvs->est_kt_arr[id]) + goto next_kt; + /* Current td released ? */ + if (td != rcu_dereference_protected(kd->ticks[row], 1)) + goto next_kt; + /* No fatal changes on the current kd and td */ + } + est = hlist_entry_safe(td->chains[cid].first, struct ip_vs_estimator, + list); + if (!est) { + cid++; + if (cid >= IPVS_EST_TICK_CHAINS) + goto next_kt; + goto walk_chain; + } + /* We can cheat and increase est_count to protect kt 0 context + * from release but we prefer to keep the last estimator + */ + last = kd->est_count <= 1; + /* Do not free kt #0 data */ + if (!id && last) + goto next_delay; + last_td = kd->tick_len[row] <= 1; + stats = container_of(est, struct ip_vs_stats, est); + ip_vs_stop_estimator(ipvs, stats); + /* Tasks are stopped, move without RCU grace period */ + est->ktid = -1; + est->ktrow = row - kd->est_row; + if (est->ktrow < 0) + est->ktrow += IPVS_EST_NTICKS; + hlist_add_head(&est->list, &ipvs->est_temp_list); + /* kd freed ? */ + if (last) + goto next_kt; + /* td freed ? */ + if (last_td) + goto next_kt; + goto walk_chain; + +end_dequeue: + /* All estimators removed while calculating ? */ + if (!ipvs->est_kt_count) + goto unlock; + kd = ipvs->est_kt_arr[0]; + if (!kd) + goto unlock; + kd->add_row = kd->est_row; + ipvs->est_chain_max = chain_max; + ip_vs_est_set_params(ipvs, kd); + + pr_info("using max %d ests per chain, %d per kthread\n", + kd->chain_max, kd->est_max_count); + + /* Try to keep tot_stats in kt0, enqueue it early */ + if (ipvs->tot_stats && !hlist_unhashed(&ipvs->tot_stats->s.est.list) && + ipvs->tot_stats->s.est.ktid == -1) { + hlist_del(&ipvs->tot_stats->s.est.list); + hlist_add_head(&ipvs->tot_stats->s.est.list, + &ipvs->est_temp_list); + } + + mutex_lock(&ipvs->est_mutex); + + /* We completed the calc phase, new calc phase not requested */ + if (genid == atomic_read(&ipvs->est_genid)) + ipvs->est_calc_phase = 0; + +unlock2: + mutex_unlock(&ipvs->est_mutex); + +unlock: + mutex_unlock(&__ip_vs_mutex); } void ip_vs_zero_estimator(struct ip_vs_stats *stats) @@ -191,14 +920,25 @@ void ip_vs_read_estimator(struct ip_vs_kstats *dst, struct ip_vs_stats *stats) int __net_init ip_vs_estimator_net_init(struct netns_ipvs *ipvs) { - INIT_LIST_HEAD(&ipvs->est_list); - spin_lock_init(&ipvs->est_lock); - timer_setup(&ipvs->est_timer, estimation_timer, 0); - mod_timer(&ipvs->est_timer, jiffies + 2 * HZ); + INIT_HLIST_HEAD(&ipvs->est_temp_list); + ipvs->est_kt_arr = NULL; + ipvs->est_max_threads = 0; + ipvs->est_calc_phase = 0; + ipvs->est_chain_max = 0; + ipvs->est_kt_count = 0; + ipvs->est_add_ktid = 0; + atomic_set(&ipvs->est_genid, 0); + atomic_set(&ipvs->est_genid_done, 0); + __mutex_init(&ipvs->est_mutex, "ipvs->est_mutex", &__ipvs_est_key); return 0; } void __net_exit ip_vs_estimator_net_cleanup(struct netns_ipvs *ipvs) { - del_timer_sync(&ipvs->est_timer); + int i; + + for (i = 0; i < ipvs->est_kt_count; i++) + ip_vs_est_kthread_destroy(ipvs->est_kt_arr[i]); + kfree(ipvs->est_kt_arr); + mutex_destroy(&ipvs->est_mutex); }