ipvs: run_estimation should control the kthread tasks

Change the run_estimation flag to start/stop the kthread tasks.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Cc: yunhong-cgl jiang <xintian1976@gmail.com>
Cc: "dust.li" <dust.li@linux.alibaba.com>
Reviewed-by: Jiri Wiesner <jwiesner@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Documentation/networking/ipvs-sysctl.rst

@@ -324,8 +324,8 @@ run_estimation - BOOLEAN
 	0 - disabled
 	not 0 - enabled (default)
 
-	If disabled, the estimation will be stop, and you can't see
-	any update on speed estimation data.
+	If disabled, the estimation will be suspended and kthread tasks
+	stopped.
 
 	You can always re-enable estimation by setting this value to 1.
 	But be careful, the first estimation after re-enable is not

include/net/ip_vs.h

@@ -1605,8 +1605,10 @@ void ip_vs_est_kthread_stop(struct ip_vs_est_kt_data *kd);
 static inline void ip_vs_est_stopped_recalc(struct netns_ipvs *ipvs)
 {
 #ifdef CONFIG_SYSCTL
-	ipvs->est_stopped = ipvs->est_cpulist_valid &&
-			    cpumask_empty(sysctl_est_cpulist(ipvs));
+	/* Stop tasks while cpulist is empty or if disabled with flag */
+	ipvs->est_stopped = !sysctl_run_estimation(ipvs) ||
+			    (ipvs->est_cpulist_valid &&
+			     cpumask_empty(sysctl_est_cpulist(ipvs)));
 #endif
 }
 

net/netfilter/ipvs/ip_vs_ctl.c

@@ -2056,6 +2056,32 @@ static int ipvs_proc_est_nice(struct ctl_table *table, int write,
 	return ret;
 }
 
+static int ipvs_proc_run_estimation(struct ctl_table *table, int write,
+				    void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct netns_ipvs *ipvs = table->extra2;
+	int *valp = table->data;
+	int val = *valp;
+	int ret;
+
+	struct ctl_table tmp_table = {
+		.data = &val,
+		.maxlen = sizeof(int),
+		.mode = table->mode,
+	};
+
+	ret = proc_dointvec(&tmp_table, write, buffer, lenp, ppos);
+	if (write && ret >= 0) {
+		mutex_lock(&ipvs->est_mutex);
+		if (*valp != val) {
+			*valp = val;
+			ip_vs_est_reload_start(ipvs);
+		}
+		mutex_unlock(&ipvs->est_mutex);
+	}
+	return ret;
+}
+
 /*
  *	IPVS sysctl table (under the /proc/sys/net/ipv4/vs/)
  *	Do not change order or insert new entries without
@@ -2230,7 +2256,7 @@ static struct ctl_table vs_vars[] = {
 		.procname	= "run_estimation",
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= ipvs_proc_run_estimation,
 	},
 	{
 		.procname	= "est_cpulist",
@@ -4323,6 +4349,7 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs)
 	tbl[idx++].data = &ipvs->sysctl_schedule_icmp;
 	tbl[idx++].data = &ipvs->sysctl_ignore_tunneled;
 	ipvs->sysctl_run_estimation = 1;
+	tbl[idx].extra2 = ipvs;
 	tbl[idx++].data = &ipvs->sysctl_run_estimation;
 
 	ipvs->est_cpulist_valid = 0;

net/netfilter/ipvs/ip_vs_est.c

@@ -212,7 +212,7 @@ static int ip_vs_estimation_kthread(void *data)
 				kd->est_timer = now;
 		}
 
-		if (sysctl_run_estimation(ipvs) && kd->tick_len[row])
+		if (kd->tick_len[row])
 			ip_vs_tick_estimation(kd, row);
 
 		row++;