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| author | Eric Dumazet <edumazet@google.com> | 2015-07-06 14:18:05 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-07-08 22:50:42 +0200 |
| commit | cef5ecf96b28dc91c4e9f398a336c578fb9e1a0c (patch) | |
| tree | 34bf7a7c6ed21b21a2c9a480df00e1e7e3335e11 /net/sched/act_gact.c | |
| parent | net: sched: add percpu stats to actions (diff) | |
| download | linux-cef5ecf96b28dc91c4e9f398a336c578fb9e1a0c.tar.xz linux-cef5ecf96b28dc91c4e9f398a336c578fb9e1a0c.zip | |
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: Eric Dumazet <edumazet@google.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/act_gact.c')
| -rw-r--r-- | net/sched/act_gact.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c index a4f8af29ee30..22a3a61aa090 100644 --- a/net/sched/act_gact.c +++ b/net/sched/act_gact.c @@ -28,14 +28,16 @@ #ifdef CONFIG_GACT_PROB 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->tcfg_paction; } 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->tcfg_paction; } @@ -105,7 +107,11 @@ static int tcf_gact_init(struct net *net, struct nlattr *nla, #ifdef CONFIG_GACT_PROB if (p_parm) { 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; } #endif |