forked from luck/tmp_suning_uos_patched
net/sched: act_csum: don't use spinlock in the fast path
use RCU instead of spin_{,unlock}_bh() to protect concurrent read/write on
act_csum configuration, to reduce the effects of contention in the data
path when multiple readers are present.
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Davide Caratti
David S. Miller
parent
f6052cf2fc
commit
9c5f69bbd7
|
|
@ -6,10 +6,16 @@
|
|||
#include <net/act_api.h>
|
||||
#include <linux/tc_act/tc_csum.h>
|
||||
|
||||
struct tcf_csum_params {
|
||||
int action;
|
||||
u32 update_flags;
|
||||
struct rcu_head rcu;
|
||||
};
|
||||
|
||||
struct tcf_csum {
|
||||
struct tc_action common;
|
||||
|
||||
u32 update_flags;
|
||||
struct tcf_csum_params __rcu *params;
|
||||
};
|
||||
#define to_tcf_csum(a) ((struct tcf_csum *)a)
|
||||
|
||||
|
|
@ -24,7 +30,13 @@ static inline bool is_tcf_csum(const struct tc_action *a)
|
|||
|
||||
static inline u32 tcf_csum_update_flags(const struct tc_action *a)
|
||||
{
|
||||
return to_tcf_csum(a)->update_flags;
|
||||
u32 update_flags;
|
||||
|
||||
rcu_read_lock();
|
||||
update_flags = rcu_dereference(to_tcf_csum(a)->params)->update_flags;
|
||||
rcu_read_unlock();
|
||||
|
||||
return update_flags;
|
||||
}
|
||||
|
||||
#endif /* __NET_TC_CSUM_H */
|
||||
|
|
|
|||
|
|
@ -49,6 +49,7 @@ static int tcf_csum_init(struct net *net, struct nlattr *nla,
|
|||
int bind)
|
||||
{
|
||||
struct tc_action_net *tn = net_generic(net, csum_net_id);
|
||||
struct tcf_csum_params *params_old, *params_new;
|
||||
struct nlattr *tb[TCA_CSUM_MAX + 1];
|
||||
struct tc_csum *parm;
|
||||
struct tcf_csum *p;
|
||||
|
|
@ -80,10 +81,21 @@ static int tcf_csum_init(struct net *net, struct nlattr *nla,
|
|||
}
|
||||
|
||||
p = to_tcf_csum(*a);
|
||||
spin_lock_bh(&p->tcf_lock);
|
||||
p->tcf_action = parm->action;
|
||||
p->update_flags = parm->update_flags;
|
||||
spin_unlock_bh(&p->tcf_lock);
|
||||
ASSERT_RTNL();
|
||||
|
||||
params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
|
||||
if (unlikely(!params_new)) {
|
||||
if (ret == ACT_P_CREATED)
|
||||
tcf_idr_release(*a, bind);
|
||||
return -ENOMEM;
|
||||
}
|
||||
params_old = rtnl_dereference(p->params);
|
||||
|
||||
params_new->action = parm->action;
|
||||
params_new->update_flags = parm->update_flags;
|
||||
rcu_assign_pointer(p->params, params_new);
|
||||
if (params_old)
|
||||
kfree_rcu(params_old, rcu);
|
||||
|
||||
if (ret == ACT_P_CREATED)
|
||||
tcf_idr_insert(tn, *a);
|
||||
|
|
@ -539,19 +551,21 @@ static int tcf_csum(struct sk_buff *skb, const struct tc_action *a,
|
|||
struct tcf_result *res)
|
||||
{
|
||||
struct tcf_csum *p = to_tcf_csum(a);
|
||||
int action;
|
||||
struct tcf_csum_params *params;
|
||||
u32 update_flags;
|
||||
int action;
|
||||
|
||||
rcu_read_lock();
|
||||
params = rcu_dereference(p->params);
|
||||
|
||||
tcf_lastuse_update(&p->tcf_tm);
|
||||
bstats_cpu_update(this_cpu_ptr(p->common.cpu_bstats), skb);
|
||||
spin_lock(&p->tcf_lock);
|
||||
action = p->tcf_action;
|
||||
update_flags = p->update_flags;
|
||||
spin_unlock(&p->tcf_lock);
|
||||
|
||||
action = params->action;
|
||||
if (unlikely(action == TC_ACT_SHOT))
|
||||
goto drop;
|
||||
goto drop_stats;
|
||||
|
||||
update_flags = params->update_flags;
|
||||
switch (tc_skb_protocol(skb)) {
|
||||
case cpu_to_be16(ETH_P_IP):
|
||||
if (!tcf_csum_ipv4(skb, update_flags))
|
||||
|
|
@ -563,11 +577,16 @@ static int tcf_csum(struct sk_buff *skb, const struct tc_action *a,
|
|||
break;
|
||||
}
|
||||
|
||||
unlock:
|
||||
rcu_read_unlock();
|
||||
return action;
|
||||
|
||||
drop:
|
||||
action = TC_ACT_SHOT;
|
||||
|
||||
drop_stats:
|
||||
qstats_drop_inc(this_cpu_ptr(p->common.cpu_qstats));
|
||||
return TC_ACT_SHOT;
|
||||
goto unlock;
|
||||
}
|
||||
|
||||
static int tcf_csum_dump(struct sk_buff *skb, struct tc_action *a, int bind,
|
||||
|
|
@ -575,15 +594,18 @@ static int tcf_csum_dump(struct sk_buff *skb, struct tc_action *a, int bind,
|
|||
{
|
||||
unsigned char *b = skb_tail_pointer(skb);
|
||||
struct tcf_csum *p = to_tcf_csum(a);
|
||||
struct tcf_csum_params *params;
|
||||
struct tc_csum opt = {
|
||||
.update_flags = p->update_flags,
|
||||
.index = p->tcf_index,
|
||||
.action = p->tcf_action,
|
||||
.refcnt = p->tcf_refcnt - ref,
|
||||
.bindcnt = p->tcf_bindcnt - bind,
|
||||
};
|
||||
struct tcf_t t;
|
||||
|
||||
params = rtnl_dereference(p->params);
|
||||
opt.action = params->action;
|
||||
opt.update_flags = params->update_flags;
|
||||
|
||||
if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
|
||||
goto nla_put_failure;
|
||||
|
||||
|
|
@ -598,6 +620,15 @@ static int tcf_csum_dump(struct sk_buff *skb, struct tc_action *a, int bind,
|
|||
return -1;
|
||||
}
|
||||
|
||||
static void tcf_csum_cleanup(struct tc_action *a)
|
||||
{
|
||||
struct tcf_csum *p = to_tcf_csum(a);
|
||||
struct tcf_csum_params *params;
|
||||
|
||||
params = rcu_dereference_protected(p->params, 1);
|
||||
kfree_rcu(params, rcu);
|
||||
}
|
||||
|
||||
static int tcf_csum_walker(struct net *net, struct sk_buff *skb,
|
||||
struct netlink_callback *cb, int type,
|
||||
const struct tc_action_ops *ops)
|
||||
|
|
@ -621,6 +652,7 @@ static struct tc_action_ops act_csum_ops = {
|
|||
.act = tcf_csum,
|
||||
.dump = tcf_csum_dump,
|
||||
.init = tcf_csum_init,
|
||||
.cleanup = tcf_csum_cleanup,
|
||||
.walk = tcf_csum_walker,
|
||||
.lookup = tcf_csum_search,
|
||||
.size = sizeof(struct tcf_csum),
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user