Commit cef5ecf9 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net_sched: act_gact: make tcfg_pval non zero 



First step for gact RCU operation :

Instead of testing if tcfg_pval is zero or not, just make it 1.

No change in behavior, but slightly faster code.

The smp_rmb()/smp_wmb() barriers, while not strictly needed at this
stage are added for upcoming spinlock removal.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Acked-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 519c818e

net/sched/act_gact.c

+9 −3
Original line number Original line Diff line number Diff line
@@ -28,14 +28,16 @@ 
#ifdef CONFIG_GACT_PROB

#ifdef CONFIG_GACT_PROB

static int gact_net_rand(struct tcf_gact *gact)

static int gact_net_rand(struct tcf_gact *gact)

{

{

	if (!gact->tcfg_pval || prandom_u32() % gact->tcfg_pval)

	smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */

	if (prandom_u32() % gact->tcfg_pval)

		return gact->tcf_action;

		return gact->tcf_action;

	return gact->tcfg_paction;

	return gact->tcfg_paction;

}

}





static int gact_determ(struct tcf_gact *gact)

static int gact_determ(struct tcf_gact *gact)

{

{

	if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval)

	smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */

	if (gact->tcf_bstats.packets % gact->tcfg_pval)

		return gact->tcf_action;

		return gact->tcf_action;

	return gact->tcfg_paction;

	return gact->tcfg_paction;

}

}
@@ -105,7 +107,11 @@ static int tcf_gact_init(struct net *net, struct nlattr *nla, 
#ifdef CONFIG_GACT_PROB

#ifdef CONFIG_GACT_PROB

	if (p_parm) {

	if (p_parm) {

		gact->tcfg_paction = p_parm->paction;

		gact->tcfg_paction = p_parm->paction;

		gact->tcfg_pval    = p_parm->pval;

		gact->tcfg_pval    = max_t(u16, 1, p_parm->pval);

		/* Make sure tcfg_pval is written before tcfg_ptype

		 * coupled with smp_rmb() in gact_net_rand() & gact_determ()

		 */

		smp_wmb();

		gact->tcfg_ptype   = p_parm->ptype;

		gact->tcfg_ptype   = p_parm->ptype;

	}

	}

#endif

#endif

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