2023-07-07 03:07:50

by Dust Li

[permalink] [raw]
Subject: [PATCH net-next] ipvs: make ip_vs_svc_table and ip_vs_svc_fwm_table per netns

From: Jiejian Wu <[email protected]>

Current ipvs uses one global mutex "__ip_vs_mutex" to keep the global
"ip_vs_svc_table" and "ip_vs_svc_fwm_table" safe. But when there are
tens of thousands of services from different netns in the table, it
takes a long time to look up the table, for example, using "ipvsadm
-ln" from different netns simultaneously.

We make "ip_vs_svc_table" and "ip_vs_svc_fwm_table" per netns, and we
add "service_mutex" per netns to keep these two tables safe instead of
the global "__ip_vs_mutex" in current version. To this end, looking up
services from different netns simultaneously will not get stuck,
shortening the time consumption in large-scale deployment. Evaluation
methods and results are provided below.

init.sh: #!/bin/bash
for((i=1;i<=4;i++));do
ip netns add ns$i
ip netns exec ns$i ip link set dev lo up
ip netns exec ns$i sh add-services.sh
done

add-services.sh: #!/bin/bash
for((i=0;i<30000;i++)); do
ipvsadm -A -t 10.10.10.10:$((80+$i)) -s rr
done

runtest.sh: #!/bin/bash
for((i=1;i<4;i++));do
ip netns exec ns$i ipvsadm -ln > /dev/null &
done
ip netns exec ns4 ipvsadm -ln > /dev/null

Run "sh init.sh" to initiate the network environment. Then run "time
./runtest.sh" to evaluate the time consumption. Our testbed is a 4-core
Intel Xeon ECS. The result of the original version is around 8 seconds,
while the result of the modified version is only 0.8 seconds.

Signed-off-by: Jiejian Wu <[email protected]>
Co-developed-by: Dust Li <[email protected]>
Signed-off-by: Dust Li <[email protected]>
---
include/net/ip_vs.h | 12 ++++
net/netfilter/ipvs/ip_vs_ctl.c | 109 +++++++++++++++------------------
2 files changed, 62 insertions(+), 59 deletions(-)

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index ff406ef4fd4aa..83ab2db4a994b 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -33,6 +33,12 @@

#define IP_VS_HDR_INVERSE 1
#define IP_VS_HDR_ICMP 2
+/*
+ * Hash table: for virtual service lookups
+ */
+#define IP_VS_SVC_TAB_BITS 8
+#define IP_VS_SVC_TAB_SIZE (1 << IP_VS_SVC_TAB_BITS)
+#define IP_VS_SVC_TAB_MASK (IP_VS_SVC_TAB_SIZE - 1)

/* Generic access of ipvs struct */
static inline struct netns_ipvs *net_ipvs(struct net* net)
@@ -1041,6 +1047,12 @@ struct netns_ipvs {
*/
unsigned int mixed_address_family_dests;
unsigned int hooks_afmask; /* &1=AF_INET, &2=AF_INET6 */
+
+ struct mutex service_mutex;
+ /* the service table hashed by <protocol, addr, port> */
+ struct hlist_head ip_vs_svc_table[IP_VS_SVC_TAB_SIZE];
+ /* the service table hashed by fwmark */
+ struct hlist_head ip_vs_svc_fwm_table[IP_VS_SVC_TAB_SIZE];
};

#define DEFAULT_SYNC_THRESHOLD 3
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 62606fb44d027..c8b30f9ec5106 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -50,6 +50,7 @@
MODULE_ALIAS_GENL_FAMILY(IPVS_GENL_NAME);

DEFINE_MUTEX(__ip_vs_mutex); /* Serialize configuration with sockopt/netlink */
+static struct lock_class_key __ipvs_service_key;

/* sysctl variables */

@@ -294,17 +295,6 @@ ip_vs_use_count_dec(void)
}


-/*
- * Hash table: for virtual service lookups
- */
-#define IP_VS_SVC_TAB_BITS 8
-#define IP_VS_SVC_TAB_SIZE (1 << IP_VS_SVC_TAB_BITS)
-#define IP_VS_SVC_TAB_MASK (IP_VS_SVC_TAB_SIZE - 1)
-
-/* the service table hashed by <protocol, addr, port> */
-static struct hlist_head ip_vs_svc_table[IP_VS_SVC_TAB_SIZE];
-/* the service table hashed by fwmark */
-static struct hlist_head ip_vs_svc_fwm_table[IP_VS_SVC_TAB_SIZE];


/*
@@ -359,13 +349,13 @@ static int ip_vs_svc_hash(struct ip_vs_service *svc)
*/
hash = ip_vs_svc_hashkey(svc->ipvs, svc->af, svc->protocol,
&svc->addr, svc->port);
- hlist_add_head_rcu(&svc->s_list, &ip_vs_svc_table[hash]);
+ hlist_add_head_rcu(&svc->s_list, &svc->ipvs->ip_vs_svc_table[hash]);
} else {
/*
* Hash it by fwmark in svc_fwm_table
*/
hash = ip_vs_svc_fwm_hashkey(svc->ipvs, svc->fwmark);
- hlist_add_head_rcu(&svc->f_list, &ip_vs_svc_fwm_table[hash]);
+ hlist_add_head_rcu(&svc->f_list, &svc->ipvs->ip_vs_svc_fwm_table[hash]);
}

svc->flags |= IP_VS_SVC_F_HASHED;
@@ -414,7 +404,7 @@ __ip_vs_service_find(struct netns_ipvs *ipvs, int af, __u16 protocol,
/* Check for "full" addressed entries */
hash = ip_vs_svc_hashkey(ipvs, af, protocol, vaddr, vport);

- hlist_for_each_entry_rcu(svc, &ip_vs_svc_table[hash], s_list) {
+ hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_table[hash], s_list) {
if ((svc->af == af)
&& ip_vs_addr_equal(af, &svc->addr, vaddr)
&& (svc->port == vport)
@@ -441,7 +431,7 @@ __ip_vs_svc_fwm_find(struct netns_ipvs *ipvs, int af, __u32 fwmark)
/* Check for fwmark addressed entries */
hash = ip_vs_svc_fwm_hashkey(ipvs, fwmark);

- hlist_for_each_entry_rcu(svc, &ip_vs_svc_fwm_table[hash], f_list) {
+ hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_fwm_table[hash], f_list) {
if (svc->fwmark == fwmark && svc->af == af
&& (svc->ipvs == ipvs)) {
/* HIT */
@@ -1701,7 +1691,7 @@ static int ip_vs_flush(struct netns_ipvs *ipvs, bool cleanup)
* Flush the service table hashed by <netns,protocol,addr,port>
*/
for(idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry_safe(svc, n, &ip_vs_svc_table[idx],
+ hlist_for_each_entry_safe(svc, n, &ipvs->ip_vs_svc_table[idx],
s_list) {
if (svc->ipvs == ipvs)
ip_vs_unlink_service(svc, cleanup);
@@ -1712,7 +1702,7 @@ static int ip_vs_flush(struct netns_ipvs *ipvs, bool cleanup)
* Flush the service table hashed by fwmark
*/
for(idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry_safe(svc, n, &ip_vs_svc_fwm_table[idx],
+ hlist_for_each_entry_safe(svc, n, &ipvs->ip_vs_svc_fwm_table[idx],
f_list) {
if (svc->ipvs == ipvs)
ip_vs_unlink_service(svc, cleanup);
@@ -1732,12 +1722,12 @@ void ip_vs_service_nets_cleanup(struct list_head *net_list)
struct net *net;

/* Check for "full" addressed entries */
- mutex_lock(&__ip_vs_mutex);
list_for_each_entry(net, net_list, exit_list) {
ipvs = net_ipvs(net);
+ mutex_lock(&ipvs->service_mutex);
ip_vs_flush(ipvs, true);
+ mutex_unlock(&ipvs->service_mutex);
}
- mutex_unlock(&__ip_vs_mutex);
}

/* Put all references for device (dst_cache) */
@@ -1775,9 +1765,9 @@ static int ip_vs_dst_event(struct notifier_block *this, unsigned long event,
if (event != NETDEV_DOWN || !ipvs)
return NOTIFY_DONE;
IP_VS_DBG(3, "%s() dev=%s\n", __func__, dev->name);
- mutex_lock(&__ip_vs_mutex);
+ mutex_lock(&ipvs->service_mutex);
for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry(svc, &ip_vs_svc_table[idx], s_list) {
+ hlist_for_each_entry(svc, &ipvs->ip_vs_svc_table[idx], s_list) {
if (svc->ipvs == ipvs) {
list_for_each_entry(dest, &svc->destinations,
n_list) {
@@ -1786,7 +1776,7 @@ static int ip_vs_dst_event(struct notifier_block *this, unsigned long event,
}
}

- hlist_for_each_entry(svc, &ip_vs_svc_fwm_table[idx], f_list) {
+ hlist_for_each_entry(svc, &ipvs->ip_vs_svc_fwm_table[idx], f_list) {
if (svc->ipvs == ipvs) {
list_for_each_entry(dest, &svc->destinations,
n_list) {
@@ -1802,7 +1792,7 @@ static int ip_vs_dst_event(struct notifier_block *this, unsigned long event,
ip_vs_forget_dev(dest, dev);
}
spin_unlock_bh(&ipvs->dest_trash_lock);
- mutex_unlock(&__ip_vs_mutex);
+ mutex_unlock(&ipvs->service_mutex);
return NOTIFY_DONE;
}

@@ -1826,14 +1816,14 @@ static int ip_vs_zero_all(struct netns_ipvs *ipvs)
struct ip_vs_service *svc;

for(idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry(svc, &ip_vs_svc_table[idx], s_list) {
+ hlist_for_each_entry(svc, &ipvs->ip_vs_svc_table[idx], s_list) {
if (svc->ipvs == ipvs)
ip_vs_zero_service(svc);
}
}

for(idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry(svc, &ip_vs_svc_fwm_table[idx], f_list) {
+ hlist_for_each_entry(svc, &ipvs->ip_vs_svc_fwm_table[idx], f_list) {
if (svc->ipvs == ipvs)
ip_vs_zero_service(svc);
}
@@ -2303,9 +2293,9 @@ static struct ip_vs_service *ip_vs_info_array(struct seq_file *seq, loff_t pos)

/* look in hash by protocol */
for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry_rcu(svc, &ip_vs_svc_table[idx], s_list) {
+ hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_table[idx], s_list) {
if ((svc->ipvs == ipvs) && pos-- == 0) {
- iter->table = ip_vs_svc_table;
+ iter->table = ipvs->ip_vs_svc_table;
iter->bucket = idx;
return svc;
}
@@ -2314,10 +2304,10 @@ static struct ip_vs_service *ip_vs_info_array(struct seq_file *seq, loff_t pos)

/* keep looking in fwmark */
for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry_rcu(svc, &ip_vs_svc_fwm_table[idx],
+ hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_fwm_table[idx],
f_list) {
if ((svc->ipvs == ipvs) && pos-- == 0) {
- iter->table = ip_vs_svc_fwm_table;
+ iter->table = ipvs->ip_vs_svc_fwm_table;
iter->bucket = idx;
return svc;
}
@@ -2340,6 +2330,8 @@ static void *ip_vs_info_seq_next(struct seq_file *seq, void *v, loff_t *pos)
struct hlist_node *e;
struct ip_vs_iter *iter;
struct ip_vs_service *svc;
+ struct net *net = seq_file_net(seq);
+ struct netns_ipvs *ipvs = net_ipvs(net);

++*pos;
if (v == SEQ_START_TOKEN)
@@ -2348,7 +2340,7 @@ static void *ip_vs_info_seq_next(struct seq_file *seq, void *v, loff_t *pos)
svc = v;
iter = seq->private;

- if (iter->table == ip_vs_svc_table) {
+ if (iter->table == ipvs->ip_vs_svc_table) {
/* next service in table hashed by protocol */
e = rcu_dereference(hlist_next_rcu(&svc->s_list));
if (e)
@@ -2356,13 +2348,13 @@ static void *ip_vs_info_seq_next(struct seq_file *seq, void *v, loff_t *pos)

while (++iter->bucket < IP_VS_SVC_TAB_SIZE) {
hlist_for_each_entry_rcu(svc,
- &ip_vs_svc_table[iter->bucket],
+ &ipvs->ip_vs_svc_table[iter->bucket],
s_list) {
return svc;
}
}

- iter->table = ip_vs_svc_fwm_table;
+ iter->table = ipvs->ip_vs_svc_fwm_table;
iter->bucket = -1;
goto scan_fwmark;
}
@@ -2375,7 +2367,7 @@ static void *ip_vs_info_seq_next(struct seq_file *seq, void *v, loff_t *pos)
scan_fwmark:
while (++iter->bucket < IP_VS_SVC_TAB_SIZE) {
hlist_for_each_entry_rcu(svc,
- &ip_vs_svc_fwm_table[iter->bucket],
+ &ipvs->ip_vs_svc_fwm_table[iter->bucket],
f_list)
return svc;
}
@@ -2411,7 +2403,7 @@ static int ip_vs_info_seq_show(struct seq_file *seq, void *v)

if (svc->ipvs != ipvs)
return 0;
- if (iter->table == ip_vs_svc_table) {
+ if (iter->table == ipvs->ip_vs_svc_table) {
#ifdef CONFIG_IP_VS_IPV6
if (svc->af == AF_INET6)
seq_printf(seq, "%s [%pI6]:%04X %s ",
@@ -2733,7 +2725,7 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, sockptr_t ptr, unsigned int len)
return ret;
}

- mutex_lock(&__ip_vs_mutex);
+ mutex_lock(&ipvs->service_mutex);
if (cmd == IP_VS_SO_SET_FLUSH) {
/* Flush the virtual service */
ret = ip_vs_flush(ipvs, false);
@@ -2830,7 +2822,7 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, sockptr_t ptr, unsigned int len)
}

out_unlock:
- mutex_unlock(&__ip_vs_mutex);
+ mutex_unlock(&ipvs->service_mutex);
return ret;
}

@@ -2868,7 +2860,7 @@ __ip_vs_get_service_entries(struct netns_ipvs *ipvs,
int ret = 0;

for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry(svc, &ip_vs_svc_table[idx], s_list) {
+ hlist_for_each_entry(svc, &ipvs->ip_vs_svc_table[idx], s_list) {
/* Only expose IPv4 entries to old interface */
if (svc->af != AF_INET || (svc->ipvs != ipvs))
continue;
@@ -2887,7 +2879,7 @@ __ip_vs_get_service_entries(struct netns_ipvs *ipvs,
}

for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry(svc, &ip_vs_svc_fwm_table[idx], f_list) {
+ hlist_for_each_entry(svc, &ipvs->ip_vs_svc_fwm_table[idx], f_list) {
/* Only expose IPv4 entries to old interface */
if (svc->af != AF_INET || (svc->ipvs != ipvs))
continue;
@@ -3058,7 +3050,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
return ret;
}

- mutex_lock(&__ip_vs_mutex);
+ mutex_lock(&ipvs->service_mutex);
switch (cmd) {
case IP_VS_SO_GET_VERSION:
{
@@ -3157,7 +3149,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
}

out:
- mutex_unlock(&__ip_vs_mutex);
+ mutex_unlock(&ipvs->service_mutex);
return ret;
}

@@ -3392,9 +3384,9 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
struct net *net = sock_net(skb->sk);
struct netns_ipvs *ipvs = net_ipvs(net);

- mutex_lock(&__ip_vs_mutex);
+ mutex_lock(&ipvs->service_mutex);
for (i = 0; i < IP_VS_SVC_TAB_SIZE; i++) {
- hlist_for_each_entry(svc, &ip_vs_svc_table[i], s_list) {
+ hlist_for_each_entry(svc, &ipvs->ip_vs_svc_table[i], s_list) {
if (++idx <= start || (svc->ipvs != ipvs))
continue;
if (ip_vs_genl_dump_service(skb, svc, cb) < 0) {
@@ -3405,7 +3397,7 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
}

for (i = 0; i < IP_VS_SVC_TAB_SIZE; i++) {
- hlist_for_each_entry(svc, &ip_vs_svc_fwm_table[i], f_list) {
+ hlist_for_each_entry(svc, &ipvs->ip_vs_svc_fwm_table[i], f_list) {
if (++idx <= start || (svc->ipvs != ipvs))
continue;
if (ip_vs_genl_dump_service(skb, svc, cb) < 0) {
@@ -3416,7 +3408,7 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
}

nla_put_failure:
- mutex_unlock(&__ip_vs_mutex);
+ mutex_unlock(&ipvs->service_mutex);
cb->args[0] = idx;

return skb->len;
@@ -3605,7 +3597,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb,
struct net *net = sock_net(skb->sk);
struct netns_ipvs *ipvs = net_ipvs(net);

- mutex_lock(&__ip_vs_mutex);
+ mutex_lock(&ipvs->service_mutex);

/* Try to find the service for which to dump destinations */
if (nlmsg_parse_deprecated(cb->nlh, GENL_HDRLEN, attrs, IPVS_CMD_ATTR_MAX, ip_vs_cmd_policy, cb->extack))
@@ -3630,7 +3622,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb,
cb->args[0] = idx;

out_err:
- mutex_unlock(&__ip_vs_mutex);
+ mutex_unlock(&ipvs->service_mutex);

return skb->len;
}
@@ -3916,7 +3908,7 @@ static int ip_vs_genl_set_cmd(struct sk_buff *skb, struct genl_info *info)

cmd = info->genlhdr->cmd;

- mutex_lock(&__ip_vs_mutex);
+ mutex_lock(&ipvs->service_mutex);

if (cmd == IPVS_CMD_FLUSH) {
ret = ip_vs_flush(ipvs, false);
@@ -4028,7 +4020,7 @@ static int ip_vs_genl_set_cmd(struct sk_buff *skb, struct genl_info *info)
}

out:
- mutex_unlock(&__ip_vs_mutex);
+ mutex_unlock(&ipvs->service_mutex);

return ret;
}
@@ -4058,7 +4050,7 @@ static int ip_vs_genl_get_cmd(struct sk_buff *skb, struct genl_info *info)
if (!msg)
return -ENOMEM;

- mutex_lock(&__ip_vs_mutex);
+ mutex_lock(&ipvs->service_mutex);

reply = genlmsg_put_reply(msg, info, &ip_vs_genl_family, 0, reply_cmd);
if (reply == NULL)
@@ -4126,7 +4118,7 @@ static int ip_vs_genl_get_cmd(struct sk_buff *skb, struct genl_info *info)
out_err:
nlmsg_free(msg);
out:
- mutex_unlock(&__ip_vs_mutex);
+ mutex_unlock(&ipvs->service_mutex);

return ret;
}
@@ -4243,6 +4235,7 @@ static struct genl_family ip_vs_genl_family __ro_after_init = {
.small_ops = ip_vs_genl_ops,
.n_small_ops = ARRAY_SIZE(ip_vs_genl_ops),
.resv_start_op = IPVS_CMD_FLUSH + 1,
+ .parallel_ops = 1,
};

static int __init ip_vs_genl_register(void)
@@ -4411,6 +4404,13 @@ int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs)
int ret = -ENOMEM;
int idx;

+ /* Initialize service_mutex, svc_table, ip_vs_svc_fwm_table per netns */
+ __mutex_init(&ipvs->service_mutex, "ipvs->service_mutex", &__ipvs_service_key);
+ for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
+ INIT_HLIST_HEAD(&ipvs->ip_vs_svc_table[idx]);
+ INIT_HLIST_HEAD(&ipvs->ip_vs_svc_fwm_table[idx]);
+ }
+
/* Initialize rs_table */
for (idx = 0; idx < IP_VS_RTAB_SIZE; idx++)
INIT_HLIST_HEAD(&ipvs->rs_table[idx]);
@@ -4515,17 +4515,8 @@ void ip_vs_unregister_nl_ioctl(void)

int __init ip_vs_control_init(void)
{
- int idx;
int ret;

- /* Initialize svc_table, ip_vs_svc_fwm_table */
- for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- INIT_HLIST_HEAD(&ip_vs_svc_table[idx]);
- INIT_HLIST_HEAD(&ip_vs_svc_fwm_table[idx]);
- }
-
- smp_wmb(); /* Do we really need it now ? */
-
ret = register_netdevice_notifier(&ip_vs_dst_notifier);
if (ret < 0)
return ret;
--
2.19.1.6.gb485710b



2023-07-09 18:29:21

by Julian Anastasov

[permalink] [raw]
Subject: Re: [PATCH net-next] ipvs: make ip_vs_svc_table and ip_vs_svc_fwm_table per netns


Hello,

On Fri, 7 Jul 2023, Dust Li wrote:

> From: Jiejian Wu <[email protected]>
>
> Current ipvs uses one global mutex "__ip_vs_mutex" to keep the global
> "ip_vs_svc_table" and "ip_vs_svc_fwm_table" safe. But when there are
> tens of thousands of services from different netns in the table, it
> takes a long time to look up the table, for example, using "ipvsadm
> -ln" from different netns simultaneously.
>
> We make "ip_vs_svc_table" and "ip_vs_svc_fwm_table" per netns, and we
> add "service_mutex" per netns to keep these two tables safe instead of
> the global "__ip_vs_mutex" in current version. To this end, looking up
> services from different netns simultaneously will not get stuck,
> shortening the time consumption in large-scale deployment. Evaluation
> methods and results are provided below.
>
> init.sh: #!/bin/bash
> for((i=1;i<=4;i++));do
> ip netns add ns$i
> ip netns exec ns$i ip link set dev lo up
> ip netns exec ns$i sh add-services.sh
> done
>
> add-services.sh: #!/bin/bash
> for((i=0;i<30000;i++)); do
> ipvsadm -A -t 10.10.10.10:$((80+$i)) -s rr
> done
>
> runtest.sh: #!/bin/bash
> for((i=1;i<4;i++));do
> ip netns exec ns$i ipvsadm -ln > /dev/null &
> done
> ip netns exec ns4 ipvsadm -ln > /dev/null
>
> Run "sh init.sh" to initiate the network environment. Then run "time
> ./runtest.sh" to evaluate the time consumption. Our testbed is a 4-core
> Intel Xeon ECS. The result of the original version is around 8 seconds,
> while the result of the modified version is only 0.8 seconds.
>
> Signed-off-by: Jiejian Wu <[email protected]>
> Co-developed-by: Dust Li <[email protected]>
> Signed-off-by: Dust Li <[email protected]>
> ---
> include/net/ip_vs.h | 12 ++++
> net/netfilter/ipvs/ip_vs_ctl.c | 109 +++++++++++++++------------------
> 2 files changed, 62 insertions(+), 59 deletions(-)
>
> diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
> index ff406ef4fd4aa..83ab2db4a994b 100644
> --- a/include/net/ip_vs.h
> +++ b/include/net/ip_vs.h
> @@ -33,6 +33,12 @@
>
> #define IP_VS_HDR_INVERSE 1
> #define IP_VS_HDR_ICMP 2
> +/*
> + * Hash table: for virtual service lookups
> + */
> +#define IP_VS_SVC_TAB_BITS 8
> +#define IP_VS_SVC_TAB_SIZE (1 << IP_VS_SVC_TAB_BITS)
> +#define IP_VS_SVC_TAB_MASK (IP_VS_SVC_TAB_SIZE - 1)
>
> /* Generic access of ipvs struct */
> static inline struct netns_ipvs *net_ipvs(struct net* net)
> @@ -1041,6 +1047,12 @@ struct netns_ipvs {
> */
> unsigned int mixed_address_family_dests;
> unsigned int hooks_afmask; /* &1=AF_INET, &2=AF_INET6 */
> +
> + struct mutex service_mutex;
> + /* the service table hashed by <protocol, addr, port> */
> + struct hlist_head ip_vs_svc_table[IP_VS_SVC_TAB_SIZE];
> + /* the service table hashed by fwmark */
> + struct hlist_head ip_vs_svc_fwm_table[IP_VS_SVC_TAB_SIZE];

Can we use svc_table and svc_fwm_table for the table names?

> };
>
> #define DEFAULT_SYNC_THRESHOLD 3
> diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> index 62606fb44d027..c8b30f9ec5106 100644
> --- a/net/netfilter/ipvs/ip_vs_ctl.c
> +++ b/net/netfilter/ipvs/ip_vs_ctl.c

> @@ -414,7 +404,7 @@ __ip_vs_service_find(struct netns_ipvs *ipvs, int af, __u16 protocol,
> /* Check for "full" addressed entries */
> hash = ip_vs_svc_hashkey(ipvs, af, protocol, vaddr, vport);
>
> - hlist_for_each_entry_rcu(svc, &ip_vs_svc_table[hash], s_list) {
> + hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_table[hash], s_list) {
> if ((svc->af == af)
> && ip_vs_addr_equal(af, &svc->addr, vaddr)
> && (svc->port == vport)
> @@ -441,7 +431,7 @@ __ip_vs_svc_fwm_find(struct netns_ipvs *ipvs, int af, __u32 fwmark)
> /* Check for fwmark addressed entries */
> hash = ip_vs_svc_fwm_hashkey(ipvs, fwmark);
>
> - hlist_for_each_entry_rcu(svc, &ip_vs_svc_fwm_table[hash], f_list) {
> + hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_fwm_table[hash], f_list) {
> if (svc->fwmark == fwmark && svc->af == af
> && (svc->ipvs == ipvs)) {

__ip_vs_service_find and __ip_vs_svc_fwm_find: match
by svc->ipvs is not needed anymore. There are other svc->ipvs == ipvs
checks in this file.

> @@ -1732,12 +1722,12 @@ void ip_vs_service_nets_cleanup(struct list_head *net_list)
> struct net *net;
>
> /* Check for "full" addressed entries */
> - mutex_lock(&__ip_vs_mutex);
> list_for_each_entry(net, net_list, exit_list) {
> ipvs = net_ipvs(net);
> + mutex_lock(&ipvs->service_mutex);
> ip_vs_flush(ipvs, true);
> + mutex_unlock(&ipvs->service_mutex);
> }
> - mutex_unlock(&__ip_vs_mutex);

This reverts speedups from commit 5d5a0815f854 but with some
reordering we probably can remove the mutex completely as part from
further optimizations.

> }
>
> /* Put all references for device (dst_cache) */
> @@ -1775,9 +1765,9 @@ static int ip_vs_dst_event(struct notifier_block *this, unsigned long event,
> if (event != NETDEV_DOWN || !ipvs)
> return NOTIFY_DONE;
> IP_VS_DBG(3, "%s() dev=%s\n", __func__, dev->name);
> - mutex_lock(&__ip_vs_mutex);
> + mutex_lock(&ipvs->service_mutex);

Looks like with global notifier we have a problem where
ip_vs_dst_event() can not know if net->ipvs is not in process
of freeing from another CPU. The global __ip_vs_mutex helped
to avoid the problem, if we see svc then svc->ipvs is valid.
But now even the ipvs->dest_trash_lock access looks under risk.
Probably, we should switch to register_netdevice_notifier_net,
so that ip_vs_dst_event() can safely work with the ipvs struct.
At first look, unregister_netdevice_notifier_net() should be
called in ip_vs_control_net_cleanup() just after the
ip_vs_trash_cleanup() call. A drawback is that when we unregister
from netns exit context __unregister_netdevice_notifier_net()
still calls call_netdevice_unregister_net_notifiers, something
that we do not want. May be we can silence these events with
some new wrapper/parameter.

> @@ -2303,9 +2293,9 @@ static struct ip_vs_service *ip_vs_info_array(struct seq_file *seq, loff_t pos)
>
> /* look in hash by protocol */
> for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
> - hlist_for_each_entry_rcu(svc, &ip_vs_svc_table[idx], s_list) {
> + hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_table[idx], s_list) {
> if ((svc->ipvs == ipvs) && pos-- == 0) {
> - iter->table = ip_vs_svc_table;
> + iter->table = ipvs->ip_vs_svc_table;

We can change iter->table to int table_id, 0 (ip_vs_svc_table)
and 1 (ip_vs_svc_fwm_table), for all these ip_vs_info_* funcs.

> iter->bucket = idx;
> return svc;
> }
> @@ -2314,10 +2304,10 @@ static struct ip_vs_service *ip_vs_info_array(struct seq_file *seq, loff_t pos)
>
> /* keep looking in fwmark */
> for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
> - hlist_for_each_entry_rcu(svc, &ip_vs_svc_fwm_table[idx],
> + hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_fwm_table[idx],
> f_list) {
> if ((svc->ipvs == ipvs) && pos-- == 0) {
> - iter->table = ip_vs_svc_fwm_table;
> + iter->table = ipvs->ip_vs_svc_fwm_table;
> iter->bucket = idx;
> return svc;
> }

> @@ -3058,7 +3050,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
> return ret;
> }
>
> - mutex_lock(&__ip_vs_mutex);
> + mutex_lock(&ipvs->service_mutex);
> switch (cmd) {
> case IP_VS_SO_GET_VERSION:
> {
> @@ -3157,7 +3149,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
> }
>
> out:
> - mutex_unlock(&__ip_vs_mutex);
> + mutex_unlock(&ipvs->service_mutex);
> return ret;
> }
>
> @@ -3392,9 +3384,9 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
> struct net *net = sock_net(skb->sk);
> struct netns_ipvs *ipvs = net_ipvs(net);
>
> - mutex_lock(&__ip_vs_mutex);
> + mutex_lock(&ipvs->service_mutex);

While do_ip_vs_get_ctl is a reader that can block we
can not use RCU but in ip_vs_genl_dump_services() we can replace
the __ip_vs_mutex with rcu_read_lock because we just fill the skb.

> for (i = 0; i < IP_VS_SVC_TAB_SIZE; i++) {
> - hlist_for_each_entry(svc, &ip_vs_svc_table[i], s_list) {
> + hlist_for_each_entry(svc, &ipvs->ip_vs_svc_table[i], s_list) {
> if (++idx <= start || (svc->ipvs != ipvs))
> continue;
> if (ip_vs_genl_dump_service(skb, svc, cb) < 0) {
> @@ -3405,7 +3397,7 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
> }
>
> for (i = 0; i < IP_VS_SVC_TAB_SIZE; i++) {
> - hlist_for_each_entry(svc, &ip_vs_svc_fwm_table[i], f_list) {
> + hlist_for_each_entry(svc, &ipvs->ip_vs_svc_fwm_table[i], f_list) {
> if (++idx <= start || (svc->ipvs != ipvs))
> continue;
> if (ip_vs_genl_dump_service(skb, svc, cb) < 0) {
> @@ -3416,7 +3408,7 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
> }
>
> nla_put_failure:
> - mutex_unlock(&__ip_vs_mutex);
> + mutex_unlock(&ipvs->service_mutex);
> cb->args[0] = idx;
>
> return skb->len;
> @@ -3605,7 +3597,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb,
> struct net *net = sock_net(skb->sk);
> struct netns_ipvs *ipvs = net_ipvs(net);
>
> - mutex_lock(&__ip_vs_mutex);
> + mutex_lock(&ipvs->service_mutex);

In ip_vs_genl_dump_dests() we can use RCU too but there
will be probably double rcu_read_lock in ip_vs_genl_parse_service(),
so rcu_read_lock can be moved into the top caller.

>
> /* Try to find the service for which to dump destinations */
> if (nlmsg_parse_deprecated(cb->nlh, GENL_HDRLEN, attrs, IPVS_CMD_ATTR_MAX, ip_vs_cmd_policy, cb->extack))
> @@ -3630,7 +3622,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb,
> cb->args[0] = idx;
>
> out_err:
> - mutex_unlock(&__ip_vs_mutex);
> + mutex_unlock(&ipvs->service_mutex);
>
> return skb->len;
> }

> @@ -4058,7 +4050,7 @@ static int ip_vs_genl_get_cmd(struct sk_buff *skb, struct genl_info *info)
> if (!msg)
> return -ENOMEM;
>
> - mutex_lock(&__ip_vs_mutex);
> + mutex_lock(&ipvs->service_mutex);

ip_vs_genl_get_cmd is another place that we can use RCU.

>
> reply = genlmsg_put_reply(msg, info, &ip_vs_genl_family, 0, reply_cmd);
> if (reply == NULL)
> @@ -4126,7 +4118,7 @@ static int ip_vs_genl_get_cmd(struct sk_buff *skb, struct genl_info *info)
> out_err:
> nlmsg_free(msg);
> out:
> - mutex_unlock(&__ip_vs_mutex);
> + mutex_unlock(&ipvs->service_mutex);
>
> return ret;
> }

Note that ip_vs_est.c uses __ip_vs_mutex too, it should be
changed to service_mutex. Do not keep __ip_vs_mutex anymore.

Also, there is more work if we want independent
namespaces and to give power to users:

- account memory: GFP_KERNEL -> GFP_KERNEL_ACCOUNT

- the connections table is still global but it should be possible
to make all tables per-net and to grow on load from NULL to max bits

- convert GENL_ADMIN_PERM -> GENL_UNS_ADMIN_PERM and make
sysctls visible to other namespaces

If the plan is to have multiple netns loaded with many
conns may be I can follow your patch with more optimization
patches.

Regards

--
Julian Anastasov <[email protected]>


2023-07-10 16:19:36

by Dust Li

[permalink] [raw]
Subject: Re: [PATCH net-next] ipvs: make ip_vs_svc_table and ip_vs_svc_fwm_table per netns

On Sun, Jul 09, 2023 at 08:45:19PM +0300, Julian Anastasov wrote:
>
> Hello,
>
>On Fri, 7 Jul 2023, Dust Li wrote:
>
>> From: Jiejian Wu <[email protected]>
>>
>> Current ipvs uses one global mutex "__ip_vs_mutex" to keep the global
>> "ip_vs_svc_table" and "ip_vs_svc_fwm_table" safe. But when there are
>> tens of thousands of services from different netns in the table, it
>> takes a long time to look up the table, for example, using "ipvsadm
>> -ln" from different netns simultaneously.
>>
>> We make "ip_vs_svc_table" and "ip_vs_svc_fwm_table" per netns, and we
>> add "service_mutex" per netns to keep these two tables safe instead of
>> the global "__ip_vs_mutex" in current version. To this end, looking up
>> services from different netns simultaneously will not get stuck,
>> shortening the time consumption in large-scale deployment. Evaluation
>> methods and results are provided below.
>>
>> init.sh: #!/bin/bash
>> for((i=1;i<=4;i++));do
>> ip netns add ns$i
>> ip netns exec ns$i ip link set dev lo up
>> ip netns exec ns$i sh add-services.sh
>> done
>>
>> add-services.sh: #!/bin/bash
>> for((i=0;i<30000;i++)); do
>> ipvsadm -A -t 10.10.10.10:$((80+$i)) -s rr
>> done
>>
>> runtest.sh: #!/bin/bash
>> for((i=1;i<4;i++));do
>> ip netns exec ns$i ipvsadm -ln > /dev/null &
>> done
>> ip netns exec ns4 ipvsadm -ln > /dev/null
>>
>> Run "sh init.sh" to initiate the network environment. Then run "time
>> ./runtest.sh" to evaluate the time consumption. Our testbed is a 4-core
>> Intel Xeon ECS. The result of the original version is around 8 seconds,
>> while the result of the modified version is only 0.8 seconds.
>>
>> Signed-off-by: Jiejian Wu <[email protected]>
>> Co-developed-by: Dust Li <[email protected]>
>> Signed-off-by: Dust Li <[email protected]>
>> ---
>> include/net/ip_vs.h | 12 ++++
>> net/netfilter/ipvs/ip_vs_ctl.c | 109 +++++++++++++++------------------
>> 2 files changed, 62 insertions(+), 59 deletions(-)
>>
>> diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
>> index ff406ef4fd4aa..83ab2db4a994b 100644
>> --- a/include/net/ip_vs.h
>> +++ b/include/net/ip_vs.h
>> @@ -33,6 +33,12 @@
>>
>> #define IP_VS_HDR_INVERSE 1
>> #define IP_VS_HDR_ICMP 2
>> +/*
>> + * Hash table: for virtual service lookups
>> + */
>> +#define IP_VS_SVC_TAB_BITS 8
>> +#define IP_VS_SVC_TAB_SIZE (1 << IP_VS_SVC_TAB_BITS)
>> +#define IP_VS_SVC_TAB_MASK (IP_VS_SVC_TAB_SIZE - 1)
>>
>> /* Generic access of ipvs struct */
>> static inline struct netns_ipvs *net_ipvs(struct net* net)
>> @@ -1041,6 +1047,12 @@ struct netns_ipvs {
>> */
>> unsigned int mixed_address_family_dests;
>> unsigned int hooks_afmask; /* &1=AF_INET, &2=AF_INET6 */
>> +
>> + struct mutex service_mutex;
>> + /* the service table hashed by <protocol, addr, port> */
>> + struct hlist_head ip_vs_svc_table[IP_VS_SVC_TAB_SIZE];
>> + /* the service table hashed by fwmark */
>> + struct hlist_head ip_vs_svc_fwm_table[IP_VS_SVC_TAB_SIZE];
>
> Can we use svc_table and svc_fwm_table for the table names?
>

Sure, will do.

>> };
>>
>> #define DEFAULT_SYNC_THRESHOLD 3
>> diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
>> index 62606fb44d027..c8b30f9ec5106 100644
>> --- a/net/netfilter/ipvs/ip_vs_ctl.c
>> +++ b/net/netfilter/ipvs/ip_vs_ctl.c
>
>> @@ -414,7 +404,7 @@ __ip_vs_service_find(struct netns_ipvs *ipvs, int af, __u16 protocol,
>> /* Check for "full" addressed entries */
>> hash = ip_vs_svc_hashkey(ipvs, af, protocol, vaddr, vport);
>>
>> - hlist_for_each_entry_rcu(svc, &ip_vs_svc_table[hash], s_list) {
>> + hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_table[hash], s_list) {
>> if ((svc->af == af)
>> && ip_vs_addr_equal(af, &svc->addr, vaddr)
>> && (svc->port == vport)
>> @@ -441,7 +431,7 @@ __ip_vs_svc_fwm_find(struct netns_ipvs *ipvs, int af, __u32 fwmark)
>> /* Check for fwmark addressed entries */
>> hash = ip_vs_svc_fwm_hashkey(ipvs, fwmark);
>>
>> - hlist_for_each_entry_rcu(svc, &ip_vs_svc_fwm_table[hash], f_list) {
>> + hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_fwm_table[hash], f_list) {
>> if (svc->fwmark == fwmark && svc->af == af
>> && (svc->ipvs == ipvs)) {
>
> __ip_vs_service_find and __ip_vs_svc_fwm_find: match
>by svc->ipvs is not needed anymore. There are other svc->ipvs == ipvs
>checks in this file.
>

Yes, will remove the check in the next version.

>> @@ -1732,12 +1722,12 @@ void ip_vs_service_nets_cleanup(struct list_head *net_list)
>> struct net *net;
>>
>> /* Check for "full" addressed entries */
>> - mutex_lock(&__ip_vs_mutex);
>> list_for_each_entry(net, net_list, exit_list) {
>> ipvs = net_ipvs(net);
>> + mutex_lock(&ipvs->service_mutex);
>> ip_vs_flush(ipvs, true);
>> + mutex_unlock(&ipvs->service_mutex);
>> }
>> - mutex_unlock(&__ip_vs_mutex);
>
> This reverts speedups from commit 5d5a0815f854 but with some
Yes :)

>reordering we probably can remove the mutex completely as part from
>further optimizations.
>

Agree. It is not a frequently called routine, so we kept it here.


>> }
>>
>> /* Put all references for device (dst_cache) */
>> @@ -1775,9 +1765,9 @@ static int ip_vs_dst_event(struct notifier_block *this, unsigned long event,
>> if (event != NETDEV_DOWN || !ipvs)
>> return NOTIFY_DONE;
>> IP_VS_DBG(3, "%s() dev=%s\n", __func__, dev->name);
>> - mutex_lock(&__ip_vs_mutex);
>> + mutex_lock(&ipvs->service_mutex);
>
> Looks like with global notifier we have a problem where
>ip_vs_dst_event() can not know if net->ipvs is not in process
>of freeing from another CPU. The global __ip_vs_mutex helped
>to avoid the problem, if we see svc then svc->ipvs is valid.
>But now even the ipvs->dest_trash_lock access looks under risk.
>Probably, we should switch to register_netdevice_notifier_net,
>so that ip_vs_dst_event() can safely work with the ipvs struct.
>At first look, unregister_netdevice_notifier_net() should be
>called in ip_vs_control_net_cleanup() just after the
>ip_vs_trash_cleanup() call. A drawback is that when we unregister
>from netns exit context __unregister_netdevice_notifier_net()
>still calls call_netdevice_unregister_net_notifiers, something
>that we do not want. May be we can silence these events with
>some new wrapper/parameter.
>
>> @@ -2303,9 +2293,9 @@ static struct ip_vs_service *ip_vs_info_array(struct seq_file *seq, loff_t pos)
>>
>> /* look in hash by protocol */
>> for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
>> - hlist_for_each_entry_rcu(svc, &ip_vs_svc_table[idx], s_list) {
>> + hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_table[idx], s_list) {
>> if ((svc->ipvs == ipvs) && pos-- == 0) {
>> - iter->table = ip_vs_svc_table;
>> + iter->table = ipvs->ip_vs_svc_table;
>
> We can change iter->table to int table_id, 0 (ip_vs_svc_table)
>and 1 (ip_vs_svc_fwm_table), for all these ip_vs_info_* funcs.

Sorry, I don't get this. Why do we need to change this ?

>
>> iter->bucket = idx;
>> return svc;
>> }
>> @@ -2314,10 +2304,10 @@ static struct ip_vs_service *ip_vs_info_array(struct seq_file *seq, loff_t pos)
>>
>> /* keep looking in fwmark */
>> for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
>> - hlist_for_each_entry_rcu(svc, &ip_vs_svc_fwm_table[idx],
>> + hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_fwm_table[idx],
>> f_list) {
>> if ((svc->ipvs == ipvs) && pos-- == 0) {
>> - iter->table = ip_vs_svc_fwm_table;
>> + iter->table = ipvs->ip_vs_svc_fwm_table;
>> iter->bucket = idx;
>> return svc;
>> }
>
>> @@ -3058,7 +3050,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
>> return ret;
>> }
>>
>> - mutex_lock(&__ip_vs_mutex);
>> + mutex_lock(&ipvs->service_mutex);
>> switch (cmd) {
>> case IP_VS_SO_GET_VERSION:
>> {
>> @@ -3157,7 +3149,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
>> }
>>
>> out:
>> - mutex_unlock(&__ip_vs_mutex);
>> + mutex_unlock(&ipvs->service_mutex);
>> return ret;
>> }
>>
>> @@ -3392,9 +3384,9 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
>> struct net *net = sock_net(skb->sk);
>> struct netns_ipvs *ipvs = net_ipvs(net);
>>
>> - mutex_lock(&__ip_vs_mutex);
>> + mutex_lock(&ipvs->service_mutex);
>
> While do_ip_vs_get_ctl is a reader that can block we
>can not use RCU but in ip_vs_genl_dump_services() we can replace
>the __ip_vs_mutex with rcu_read_lock because we just fill the skb.
>

I think we can replace mutex in ip_vs_genl_dump_services() by RCU.
Do you prefer replacing it in this patch or later ?


>> for (i = 0; i < IP_VS_SVC_TAB_SIZE; i++) {
>> - hlist_for_each_entry(svc, &ip_vs_svc_table[i], s_list) {
>> + hlist_for_each_entry(svc, &ipvs->ip_vs_svc_table[i], s_list) {
>> if (++idx <= start || (svc->ipvs != ipvs))
>> continue;
>> if (ip_vs_genl_dump_service(skb, svc, cb) < 0) {
>> @@ -3405,7 +3397,7 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
>> }
>>
>> for (i = 0; i < IP_VS_SVC_TAB_SIZE; i++) {
>> - hlist_for_each_entry(svc, &ip_vs_svc_fwm_table[i], f_list) {
>> + hlist_for_each_entry(svc, &ipvs->ip_vs_svc_fwm_table[i], f_list) {
>> if (++idx <= start || (svc->ipvs != ipvs))
>> continue;
>> if (ip_vs_genl_dump_service(skb, svc, cb) < 0) {
>> @@ -3416,7 +3408,7 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
>> }
>>
>> nla_put_failure:
>> - mutex_unlock(&__ip_vs_mutex);
>> + mutex_unlock(&ipvs->service_mutex);
>> cb->args[0] = idx;
>>
>> return skb->len;
>> @@ -3605,7 +3597,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb,
>> struct net *net = sock_net(skb->sk);
>> struct netns_ipvs *ipvs = net_ipvs(net);
>>
>> - mutex_lock(&__ip_vs_mutex);
>> + mutex_lock(&ipvs->service_mutex);
>
> In ip_vs_genl_dump_dests() we can use RCU too but there
>will be probably double rcu_read_lock in ip_vs_genl_parse_service(),
>so rcu_read_lock can be moved into the top caller.

Yes.

>
>>
>> /* Try to find the service for which to dump destinations */
>> if (nlmsg_parse_deprecated(cb->nlh, GENL_HDRLEN, attrs, IPVS_CMD_ATTR_MAX, ip_vs_cmd_policy, cb->extack))
>> @@ -3630,7 +3622,7 @@ static int ip_vs_genl_dump_dests(struct sk_buff *skb,
>> cb->args[0] = idx;
>>
>> out_err:
>> - mutex_unlock(&__ip_vs_mutex);
>> + mutex_unlock(&ipvs->service_mutex);
>>
>> return skb->len;
>> }
>
>> @@ -4058,7 +4050,7 @@ static int ip_vs_genl_get_cmd(struct sk_buff *skb, struct genl_info *info)
>> if (!msg)
>> return -ENOMEM;
>>
>> - mutex_lock(&__ip_vs_mutex);
>> + mutex_lock(&ipvs->service_mutex);
>
> ip_vs_genl_get_cmd is another place that we can use RCU.
>

OK

>>
>> reply = genlmsg_put_reply(msg, info, &ip_vs_genl_family, 0, reply_cmd);
>> if (reply == NULL)
>> @@ -4126,7 +4118,7 @@ static int ip_vs_genl_get_cmd(struct sk_buff *skb, struct genl_info *info)
>> out_err:
>> nlmsg_free(msg);
>> out:
>> - mutex_unlock(&__ip_vs_mutex);
>> + mutex_unlock(&ipvs->service_mutex);
>>
>> return ret;
>> }
>
> Note that ip_vs_est.c uses __ip_vs_mutex too, it should be
>changed to service_mutex. Do not keep __ip_vs_mutex anymore.

OK, will fix in the next version.

>
> Also, there is more work if we want independent
>namespaces and to give power to users:
>
>- account memory: GFP_KERNEL -> GFP_KERNEL_ACCOUNT
>
>- the connections table is still global but it should be possible
>to make all tables per-net and to grow on load from NULL to max bits
>
>- convert GENL_ADMIN_PERM -> GENL_UNS_ADMIN_PERM and make
>sysctls visible to other namespaces
>
> If the plan is to have multiple netns loaded with many
>conns may be I can follow your patch with more optimization
>patches.

Yes, we do missed those details. I think moving those into different
netns is good, besides we already have netns supported. So why not do
it more completely ?

If it is convenient for you to do more optimizations, we would greatly
appreciate it !

Best regards,
Dust


>
>Regards
>
>--
>Julian Anastasov <[email protected]>

2023-07-10 19:08:50

by Julian Anastasov

[permalink] [raw]
Subject: Re: [PATCH net-next] ipvs: make ip_vs_svc_table and ip_vs_svc_fwm_table per netns


Hello,

On Mon, 10 Jul 2023, Dust Li wrote:

> On Sun, Jul 09, 2023 at 08:45:19PM +0300, Julian Anastasov wrote:
> >
> > Hello,
> >
> >On Fri, 7 Jul 2023, Dust Li wrote:
> >
> >> @@ -2303,9 +2293,9 @@ static struct ip_vs_service *ip_vs_info_array(struct seq_file *seq, loff_t pos)
> >>
> >> /* look in hash by protocol */
> >> for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
> >> - hlist_for_each_entry_rcu(svc, &ip_vs_svc_table[idx], s_list) {
> >> + hlist_for_each_entry_rcu(svc, &ipvs->ip_vs_svc_table[idx], s_list) {
> >> if ((svc->ipvs == ipvs) && pos-- == 0) {
> >> - iter->table = ip_vs_svc_table;
> >> + iter->table = ipvs->ip_vs_svc_table;
> >
> > We can change iter->table to int table_id, 0 (ip_vs_svc_table)
> >and 1 (ip_vs_svc_fwm_table), for all these ip_vs_info_* funcs.
>
> Sorry, I don't get this. Why do we need to change this ?

It is a hint which table to walk, no need for such
dereferences. For example:

iter->table = ip_vs_svc_table;
becomes
iter->table_id = 0;

iter->table = ip_vs_svc_fwm_table;
becomes
iter->table_id = 1;

etc

> >> @@ -3392,9 +3384,9 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
> >> struct net *net = sock_net(skb->sk);
> >> struct netns_ipvs *ipvs = net_ipvs(net);
> >>
> >> - mutex_lock(&__ip_vs_mutex);
> >> + mutex_lock(&ipvs->service_mutex);
> >
> > While do_ip_vs_get_ctl is a reader that can block we
> >can not use RCU but in ip_vs_genl_dump_services() we can replace
> >the __ip_vs_mutex with rcu_read_lock because we just fill the skb.
> >
>
> I think we can replace mutex in ip_vs_genl_dump_services() by RCU.
> Do you prefer replacing it in this patch or later ?

You can include these RCU conversions

> > Also, there is more work if we want independent
> >namespaces and to give power to users:
> >
> >- account memory: GFP_KERNEL -> GFP_KERNEL_ACCOUNT
> >
> >- the connections table is still global but it should be possible
> >to make all tables per-net and to grow on load from NULL to max bits
> >
> >- convert GENL_ADMIN_PERM -> GENL_UNS_ADMIN_PERM and make
> >sysctls visible to other namespaces
> >
> > If the plan is to have multiple netns loaded with many
> >conns may be I can follow your patch with more optimization
> >patches.
>
> Yes, we do missed those details. I think moving those into different
> netns is good, besides we already have netns supported. So why not do
> it more completely ?
>
> If it is convenient for you to do more optimizations, we would greatly
> appreciate it !

Yes, I'll prepare more patches on top of your patch.

Regards

--
Julian Anastasov <[email protected]>