// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ip_vs_est.c: simple rate estimator for IPVS
*
* Authors: Wensong Zhang <[email protected]>
*
* Changes: Hans Schillstrom <[email protected]>
* Network name space (netns) aware.
* Global data moved to netns i.e struct netns_ipvs
* Affected data: est_list and est_lock.
* estimation_timer() runs with timer per netns.
* get_stats()) do the per cpu summing.
*/
#define KMSG_COMPONENT "IPVS"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/sysctl.h>
#include <linux/list.h>
#include <linux/rcupdate_wait.h>
#include <net/ip_vs.h>
/*
This code is to estimate rate in a shorter interval (such as 8
seconds) for virtual services and real servers. For measure rate in a
long interval, it is easy to implement a user level daemon which
periodically reads those statistical counters and measure rate.
We measure rate during the last 8 seconds every 2 seconds:
avgrate = avgrate*(1-W) + rate*W
where W = 2^(-2)
NOTES.
* Average bps is scaled by 2^5, while average pps and cps are scaled by 2^10.
* Netlink users can see 64-bit values but sockopt users are restricted
to 32-bit values for conns, packets, bps, cps and pps.
* A lot of code is taken from net/core/gen_estimator.c
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
- when configuration (cpulist/nice) is changed, the tasks are restarted
by work (est_reload_work)
- kthread tasks are stopped while the cpulist is empty
- 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 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 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;
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;
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);
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;
e->last_conns = s->kstats.conns;
e->cps += ((s64)rate - (s64)e->cps) >> 2;
rate = (s->kstats.inpkts - e->last_inpkts) << 9;
e->last_inpkts = s->kstats.inpkts;
e->inpps += ((s64)rate - (s64)e->inpps) >> 2;
rate = (s->kstats.outpkts - e->last_outpkts) << 9;
e->last_outpkts = s->kstats.outpkts;
e->outpps += ((s64)rate - (s64)e->outpps) >> 2;
/* scaled by 2^5, but divided 2 seconds */
rate = (s->kstats.inbytes - e->last_inbytes) << 4;
e->last_inbytes = s->kstats.inbytes;
e->inbps += ((s64)rate - (s64)e->inbps) >> 2;
rate = (s->kstats.outbytes - e->last_outbytes) << 4;
e->last_outbytes = s->kstats.outbytes;
e->outbps += ((s64)rate - (s64)e->outbps) >> 2;
spin_unlock(&s->lock);
}
}
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();
}
static int ip_vs_estimation_kthread(void *data)
{
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 (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;
ip_vs_est_stopped_recalc(ipvs);
/* 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;
}
set_user_nice(kd->task, sysctl_est_nice(ipvs));
set_cpus_allowed_ptr(kd->task, sysctl_est_cpulist(ipvs));
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 && !ip_vs_est_stopped(ipvs)) {
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;
}
/* 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 = ip_vs_est_max_threads(ipvs);
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;
}
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, rcu_head);
}
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;
}
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;
int max = 8;
int ret = 1;
s64 diff;
u64 val;
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)
{
struct ip_vs_estimator *est = &stats->est;
struct ip_vs_kstats *k = &stats->kstats;
/* reset counters, caller must hold the stats->lock lock */
est->last_inbytes = k->inbytes;
est->last_outbytes = k->outbytes;
est->last_conns = k->conns;
est->last_inpkts = k->inpkts;
est->last_outpkts = k->outpkts;
est->cps = 0;
est->inpps = 0;
est->outpps = 0;
est->inbps = 0;
est->outbps = 0;
}
/* Get decoded rates */
void ip_vs_read_estimator(struct ip_vs_kstats *dst, struct ip_vs_stats *stats)
{
struct ip_vs_estimator *e = &stats->est;
dst->cps = (e->cps + 0x1FF) >> 10;
dst->inpps = (e->inpps + 0x1FF) >> 10;
dst->outpps = (e->outpps + 0x1FF) >> 10;
dst->inbps = (e->inbps + 0xF) >> 5;
dst->outbps = (e->outbps + 0xF) >> 5;
}
int __net_init ip_vs_estimator_net_init(struct netns_ipvs *ipvs)
{
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)
{
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);
}
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