From a73ed26bbae7327370c5bd298f07de78df9e3466 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 9 Dec 2011 02:46:45 +0000 Subject: sch_red: generalize accurate MAX_P support to RED/GRED/CHOKE Now RED uses a Q0.32 number to store max_p (max probability), allow RED/GRED/CHOKE to use/report full resolution at config/dump time. Old tc binaries are non aware of new attributes, and still set/get Plog. New tc binary set/get both Plog and max_p for backward compatibility, they display "probability value" if they get max_p from new kernels. # tc -d qdisc show dev ... ... qdisc red 10: parent 1:1 limit 360Kb min 30Kb max 90Kb ecn ewma 5 probability 0.09 Scell_log 15 Make sure we avoid potential divides by 0 in reciprocal_value(), if (max_th - min_th) is big. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/sch_red.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'net/sched/sch_red.c') diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c index 8f5a85bf9d10..ce2256a17d7e 100644 --- a/net/sched/sch_red.c +++ b/net/sched/sch_red.c @@ -170,6 +170,7 @@ static void red_destroy(struct Qdisc *sch) static const struct nla_policy red_policy[TCA_RED_MAX + 1] = { [TCA_RED_PARMS] = { .len = sizeof(struct tc_red_qopt) }, [TCA_RED_STAB] = { .len = RED_STAB_SIZE }, + [TCA_RED_MAX_P] = { .type = NLA_U32 }, }; static int red_change(struct Qdisc *sch, struct nlattr *opt) @@ -179,6 +180,7 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt) struct tc_red_qopt *ctl; struct Qdisc *child = NULL; int err; + u32 max_P; if (opt == NULL) return -EINVAL; @@ -191,6 +193,8 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt) tb[TCA_RED_STAB] == NULL) return -EINVAL; + max_P = tb[TCA_RED_MAX_P] ? nla_get_u32(tb[TCA_RED_MAX_P]) : 0; + ctl = nla_data(tb[TCA_RED_PARMS]); if (ctl->limit > 0) { @@ -209,8 +213,9 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt) } red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog, - ctl->Plog, ctl->Scell_log, - nla_data(tb[TCA_RED_STAB])); + ctl->Plog, ctl->Scell_log, + nla_data(tb[TCA_RED_STAB]), + max_P); del_timer(&q->adapt_timer); if (ctl->flags & TC_RED_ADAPTATIVE) -- cgit v1.2.3-59-g8ed1b