From 348e3435cbefa815bd56a5205c1412b5afe7b92e Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Tue, 18 Aug 2015 10:30:49 +0200 Subject: [PATCH] net: sched: drop all special handling of tx_queue_len == 0 Those were all workarounds for the formerly double meaning of tx_queue_len, which broke scheduling algorithms if untreated. Now that all in-tree drivers have been converted away from setting tx_queue_len = 0, it should be safe to drop these workarounds for categorically broken setups. Signed-off-by: Phil Sutter Cc: Jamal Hadi Salim Signed-off-by: David S. Miller --- net/sched/sch_fifo.c | 2 +- net/sched/sch_gred.c | 8 +++----- net/sched/sch_htb.c | 6 ++---- net/sched/sch_plug.c | 8 ++------ net/sched/sch_sfb.c | 2 +- 5 files changed, 9 insertions(+), 17 deletions(-) diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c index 2e2398cfc694..2177eac0a61e 100644 --- a/net/sched/sch_fifo.c +++ b/net/sched/sch_fifo.c @@ -54,7 +54,7 @@ static int fifo_init(struct Qdisc *sch, struct nlattr *opt) bool is_bfifo = sch->ops == &bfifo_qdisc_ops; if (opt == NULL) { - u32 limit = qdisc_dev(sch)->tx_queue_len ? : 1; + u32 limit = qdisc_dev(sch)->tx_queue_len; if (is_bfifo) limit *= psched_mtu(qdisc_dev(sch)); diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c index abb9f2fec28f..80105109f756 100644 --- a/net/sched/sch_gred.c +++ b/net/sched/sch_gred.c @@ -512,11 +512,9 @@ static int gred_init(struct Qdisc *sch, struct nlattr *opt) if (tb[TCA_GRED_LIMIT]) sch->limit = nla_get_u32(tb[TCA_GRED_LIMIT]); - else { - u32 qlen = qdisc_dev(sch)->tx_queue_len ? : 1; - - sch->limit = qlen * psched_mtu(qdisc_dev(sch)); - } + else + sch->limit = qdisc_dev(sch)->tx_queue_len + * psched_mtu(qdisc_dev(sch)); return gred_change_table_def(sch, tb[TCA_GRED_DPS]); } diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index f1acb0f60dc3..cf4b0f865d1b 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -1048,11 +1048,9 @@ static int htb_init(struct Qdisc *sch, struct nlattr *opt) if (tb[TCA_HTB_DIRECT_QLEN]) q->direct_qlen = nla_get_u32(tb[TCA_HTB_DIRECT_QLEN]); - else { + else q->direct_qlen = qdisc_dev(sch)->tx_queue_len; - if (q->direct_qlen < 2) /* some devices have zero tx_queue_len */ - q->direct_qlen = 2; - } + if ((q->rate2quantum = gopt->rate2quantum) < 1) q->rate2quantum = 1; q->defcls = gopt->defcls; diff --git a/net/sched/sch_plug.c b/net/sched/sch_plug.c index ade9445a55ab..5abfe44678d4 100644 --- a/net/sched/sch_plug.c +++ b/net/sched/sch_plug.c @@ -130,12 +130,8 @@ static int plug_init(struct Qdisc *sch, struct nlattr *opt) q->unplug_indefinite = false; if (opt == NULL) { - /* We will set a default limit of 100 pkts (~150kB) - * in case tx_queue_len is not available. The - * default value is completely arbitrary. - */ - u32 pkt_limit = qdisc_dev(sch)->tx_queue_len ? : 100; - q->limit = pkt_limit * psched_mtu(qdisc_dev(sch)); + q->limit = qdisc_dev(sch)->tx_queue_len + * psched_mtu(qdisc_dev(sch)); } else { struct tc_plug_qopt *ctl = nla_data(opt); diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c index 4b815193326c..dcdff5c769a1 100644 --- a/net/sched/sch_sfb.c +++ b/net/sched/sch_sfb.c @@ -502,7 +502,7 @@ static int sfb_change(struct Qdisc *sch, struct nlattr *opt) limit = ctl->limit; if (limit == 0) - limit = max_t(u32, qdisc_dev(sch)->tx_queue_len, 1); + limit = qdisc_dev(sch)->tx_queue_len; child = fifo_create_dflt(sch, &pfifo_qdisc_ops, limit); if (IS_ERR(child))