Commit 7d12057b authored by Pedro Tammela's avatar Pedro Tammela Committed by Paolo Abeni
Browse files

net/sched: act_nat: transition to percpu stats and rcu 



The tc action act_nat was using shared stats and taking the per action
lock in the datapath. Improve it by using percpu stats and rcu.

perf before:
- 10.48% tcf_nat_act
   - 81.83% _raw_spin_lock
        81.08% native_queued_spin_lock_slowpath

perf after:
- 0.48% tcf_nat_act

tdc results:
1..27
ok 1 7565 - Add nat action on ingress with default control action
ok 2 fd79 - Add nat action on ingress with pipe control action
ok 3 eab9 - Add nat action on ingress with continue control action
ok 4 c53a - Add nat action on ingress with reclassify control action
ok 5 76c9 - Add nat action on ingress with jump control action
ok 6 24c6 - Add nat action on ingress with drop control action
ok 7 2120 - Add nat action on ingress with maximum index value
ok 8 3e9d - Add nat action on ingress with invalid index value
ok 9 f6c9 - Add nat action on ingress with invalid IP address
ok 10 be25 - Add nat action on ingress with invalid argument
ok 11 a7bd - Add nat action on ingress with DEFAULT IP address
ok 12 ee1e - Add nat action on ingress with ANY IP address
ok 13 1de8 - Add nat action on ingress with ALL IP address
ok 14 8dba - Add nat action on egress with default control action
ok 15 19a7 - Add nat action on egress with pipe control action
ok 16 f1d9 - Add nat action on egress with continue control action
ok 17 6d4a - Add nat action on egress with reclassify control action
ok 18 b313 - Add nat action on egress with jump control action
ok 19 d9fc - Add nat action on egress with drop control action
ok 20 a895 - Add nat action on egress with DEFAULT IP address
ok 21 2572 - Add nat action on egress with ANY IP address
ok 22 37f3 - Add nat action on egress with ALL IP address
ok 23 6054 - Add nat action on egress with cookie
ok 24 79d6 - Add nat action on ingress with cookie
ok 25 4b12 - Replace nat action with invalid goto chain control
ok 26 b811 - Delete nat action with valid index
ok 27 a521 - Delete nat action with invalid index

Reviewed-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarPedro Tammela <pctammela@mojatatu.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 10d13421

include/net/tc_act/tc_nat.h

+7 −3
Original line number Diff line number Diff line
@@ -5,13 +5,17 @@ 
#include <linux/types.h>

#include <net/act_api.h>



struct tcf_nat {

	struct tc_action common;



struct tcf_nat_parms {

	__be32 old_addr;

	__be32 new_addr;

	__be32 mask;

	u32 flags;

	struct rcu_head rcu;

};



struct tcf_nat {

	struct tc_action common;

	struct tcf_nat_parms __rcu *parms;

};



#define to_tcf_nat(a) ((struct tcf_nat *)a)

net/sched/act_nat.c

+49 −23
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ static int tcf_nat_init(struct net *net, struct nlattr *nla, struct nlattr *est, 
{

	struct tc_action_net *tn = net_generic(net, act_nat_ops.net_id);

	bool bind = flags & TCA_ACT_FLAGS_BIND;

	struct tcf_nat_parms *nparm, *oparm;

	struct nlattr *tb[TCA_NAT_MAX + 1];

	struct tcf_chain *goto_ch = NULL;

	struct tc_nat *parm;
@@ -59,8 +60,8 @@ static int tcf_nat_init(struct net *net, struct nlattr *nla, struct nlattr *est, 
	index = parm->index;

	err = tcf_idr_check_alloc(tn, &index, a, bind);

	if (!err) {

		ret = tcf_idr_create(tn, index, est, a,

				     &act_nat_ops, bind, false, flags);

		ret = tcf_idr_create_from_flags(tn, index, est, a, &act_nat_ops,

						bind, flags);

		if (ret) {

			tcf_idr_cleanup(tn, index);

			return ret;
@@ -79,19 +80,31 @@ static int tcf_nat_init(struct net *net, struct nlattr *nla, struct nlattr *est, 
	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);

	if (err < 0)

		goto release_idr;



	nparm = kzalloc(sizeof(*nparm), GFP_KERNEL);

	if (!nparm) {

		err = -ENOMEM;

		goto release_idr;

	}



	nparm->old_addr = parm->old_addr;

	nparm->new_addr = parm->new_addr;

	nparm->mask = parm->mask;

	nparm->flags = parm->flags;



	p = to_tcf_nat(*a);



	spin_lock_bh(&p->tcf_lock);

	p->old_addr = parm->old_addr;

	p->new_addr = parm->new_addr;

	p->mask = parm->mask;

	p->flags = parm->flags;



	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);

	oparm = rcu_replace_pointer(p->parms, nparm, lockdep_is_held(&p->tcf_lock));

	spin_unlock_bh(&p->tcf_lock);



	if (goto_ch)

		tcf_chain_put_by_act(goto_ch);



	if (oparm)

		kfree_rcu(oparm, rcu);



	return ret;

release_idr:

	tcf_idr_release(*a, bind);
@@ -103,6 +116,7 @@ TC_INDIRECT_SCOPE int tcf_nat_act(struct sk_buff *skb, 
				  struct tcf_result *res)

{

	struct tcf_nat *p = to_tcf_nat(a);

	struct tcf_nat_parms *parms;

	struct iphdr *iph;

	__be32 old_addr;

	__be32 new_addr;
@@ -113,18 +127,16 @@ TC_INDIRECT_SCOPE int tcf_nat_act(struct sk_buff *skb, 
	int ihl;

	int noff;



	spin_lock(&p->tcf_lock);



	tcf_lastuse_update(&p->tcf_tm);

	old_addr = p->old_addr;

	new_addr = p->new_addr;

	mask = p->mask;

	egress = p->flags & TCA_NAT_FLAG_EGRESS;

	action = p->tcf_action;

	tcf_action_update_bstats(&p->common, skb);



	bstats_update(&p->tcf_bstats, skb);

	action = READ_ONCE(p->tcf_action);



	spin_unlock(&p->tcf_lock);

	parms = rcu_dereference_bh(p->parms);

	old_addr = parms->old_addr;

	new_addr = parms->new_addr;

	mask = parms->mask;

	egress = parms->flags & TCA_NAT_FLAG_EGRESS;



	if (unlikely(action == TC_ACT_SHOT))

		goto drop;
@@ -248,9 +260,7 @@ TC_INDIRECT_SCOPE int tcf_nat_act(struct sk_buff *skb, 
	return action;



drop:

	spin_lock(&p->tcf_lock);

	p->tcf_qstats.drops++;

	spin_unlock(&p->tcf_lock);

	tcf_action_inc_drop_qstats(&p->common);

	return TC_ACT_SHOT;

}
@@ -264,15 +274,20 @@ static int tcf_nat_dump(struct sk_buff *skb, struct tc_action *a, 
		.refcnt   = refcount_read(&p->tcf_refcnt) - ref,

		.bindcnt  = atomic_read(&p->tcf_bindcnt) - bind,

	};

	struct tcf_nat_parms *parms;

	struct tcf_t t;



	spin_lock_bh(&p->tcf_lock);

	opt.old_addr = p->old_addr;

	opt.new_addr = p->new_addr;

	opt.mask = p->mask;

	opt.flags = p->flags;



	opt.action = p->tcf_action;



	parms = rcu_dereference_protected(p->parms, lockdep_is_held(&p->tcf_lock));



	opt.old_addr = parms->old_addr;

	opt.new_addr = parms->new_addr;

	opt.mask = parms->mask;

	opt.flags = parms->flags;



	if (nla_put(skb, TCA_NAT_PARMS, sizeof(opt), &opt))

		goto nla_put_failure;
@@ -289,6 +304,16 @@ static int tcf_nat_dump(struct sk_buff *skb, struct tc_action *a, 
	return -1;

}



static void tcf_nat_cleanup(struct tc_action *a)

{

	struct tcf_nat *p = to_tcf_nat(a);

	struct tcf_nat_parms *parms;



	parms = rcu_dereference_protected(p->parms, 1);

	if (parms)

		kfree_rcu(parms, rcu);

}



static struct tc_action_ops act_nat_ops = {

	.kind		=	"nat",

	.id		=	TCA_ID_NAT,
@@ -296,6 +321,7 @@ static struct tc_action_ops act_nat_ops = { 
	.act		=	tcf_nat_act,

	.dump		=	tcf_nat_dump,

	.init		=	tcf_nat_init,

	.cleanup	=	tcf_nat_cleanup,

	.size		=	sizeof(struct tcf_nat),

};