From 64153ce0a7b61b2a5cacb01805cbf670142339e9 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 6 Jun 2013 14:53:16 -0700 Subject: net_sched: htb: do not setup default rate estimators With a thousand htb classes, est_timer() spends ~5 million cpu cycles and throws out cpu cache, because each htb class has a default rate estimator (est 4sec 16sec). Most users do not use default rate estimators, so switch htb to not setup ones. Add a module parameter (htb_rate_est) so that users relying on this default rate estimator can revert the behavior. echo 1 >/sys/module/sch_htb/parameters/htb_rate_est Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/sch_htb.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'net/sched') diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 162fb800754c..1a3655a606c1 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -65,6 +65,10 @@ static int htb_hysteresis __read_mostly = 0; /* whether to use mode hysteresis f module_param (htb_hysteresis, int, 0640); MODULE_PARM_DESC(htb_hysteresis, "Hysteresis mode, less CPU load, less accurate"); +static int htb_rate_est = 0; /* htb classes have a default rate estimator */ +module_param(htb_rate_est, int, 0640); +MODULE_PARM_DESC(htb_rate_est, "setup a default rate estimator (4sec 16sec) for htb classes"); + /* used internaly to keep status of single class */ enum htb_cmode { HTB_CANT_SEND, /* class can't send and can't borrow */ @@ -1366,12 +1370,14 @@ static int htb_change_class(struct Qdisc *sch, u32 classid, if (!cl) goto failure; - err = gen_new_estimator(&cl->bstats, &cl->rate_est, - qdisc_root_sleeping_lock(sch), - tca[TCA_RATE] ? : &est.nla); - if (err) { - kfree(cl); - goto failure; + if (htb_rate_est || tca[TCA_RATE]) { + err = gen_new_estimator(&cl->bstats, &cl->rate_est, + qdisc_root_sleeping_lock(sch), + tca[TCA_RATE] ? : &est.nla); + if (err) { + kfree(cl); + goto failure; + } } cl->refcnt = 1; -- cgit v1.2.1