Re: [PATCH net-next] net: sched: delete duplicate cleanup of backlog and qlen

From: shaozhengchao
Date: Tue Aug 23 2022 - 20:44:24 EST




On 2022/8/24 0:29, Eric Dumazet wrote:
On Tue, Aug 23, 2022 at 12:54 AM Zhengchao Shao
<shaozhengchao@xxxxxxxxxx> wrote:

The qdisc_reset function has cleared the backlog and qlen of the qdisc.
There is no need to clear them again in the specific reset function.

changelog is slightly inaccurate.

qdisc_reset() is clearing qdisc->q.qlen and qdisc->qstats.backlog
_after_ calling qdisc->ops->reset,
not before.


Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>
---
include/net/sch_generic.h | 1 -
net/sched/sch_atm.c | 1 -
net/sched/sch_cbq.c | 1 -
net/sched/sch_choke.c | 2 --
net/sched/sch_drr.c | 2 --
net/sched/sch_dsmark.c | 2 --
net/sched/sch_etf.c | 3 ---
net/sched/sch_ets.c | 2 --
net/sched/sch_fq_codel.c | 2 --
net/sched/sch_fq_pie.c | 3 ---
net/sched/sch_hfsc.c | 2 --
net/sched/sch_htb.c | 2 --
net/sched/sch_multiq.c | 1 -
net/sched/sch_prio.c | 2 --
net/sched/sch_qfq.c | 2 --
net/sched/sch_red.c | 2 --
net/sched/sch_sfb.c | 2 --
net/sched/sch_skbprio.c | 3 ---
net/sched/sch_taprio.c | 2 --
net/sched/sch_tbf.c | 2 --
net/sched/sch_teql.c | 1 -
21 files changed, 40 deletions(-)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index ec693fe7c553..f2958fb5ae08 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -1137,7 +1137,6 @@ static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
static inline void qdisc_reset_queue(struct Qdisc *sch)
{
__qdisc_reset_queue(&sch->q);
- sch->qstats.backlog = 0;
}

static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index 4c8e994cf0a5..816fd0d7ba38 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -577,7 +577,6 @@ static void atm_tc_reset(struct Qdisc *sch)
pr_debug("atm_tc_reset(sch %p,[qdisc %p])\n", sch, p);
list_for_each_entry(flow, &p->flows, list)
qdisc_reset(flow->q);
- sch->q.qlen = 0;
}

static void atm_tc_destroy(struct Qdisc *sch)
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index af126eb3e431..b026daca160e 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -975,7 +975,6 @@ cbq_reset(struct Qdisc *sch)
cl->cpriority = cl->priority;
}
}
- sch->q.qlen = 0;
}


diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c
index 2adbd945bf15..25d2daaa8122 100644
--- a/net/sched/sch_choke.c
+++ b/net/sched/sch_choke.c
@@ -315,8 +315,6 @@ static void choke_reset(struct Qdisc *sch)
rtnl_qdisc_drop(skb, sch);
}

- sch->q.qlen = 0;
- sch->qstats.backlog = 0;
if (q->tab)
memset(q->tab, 0, (q->tab_mask + 1) * sizeof(struct sk_buff *));
q->head = q->tail = 0;
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index 18e4f7a0b291..4e5b1cf11b85 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -441,8 +441,6 @@ static void drr_reset_qdisc(struct Qdisc *sch)
qdisc_reset(cl->qdisc);
}
}
- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
}

static void drr_destroy_qdisc(struct Qdisc *sch)
diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
index 4c100d105269..7da6dc38a382 100644
--- a/net/sched/sch_dsmark.c
+++ b/net/sched/sch_dsmark.c
@@ -409,8 +409,6 @@ static void dsmark_reset(struct Qdisc *sch)
pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
if (p->q)
qdisc_reset(p->q);
- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
}

static void dsmark_destroy(struct Qdisc *sch)
diff --git a/net/sched/sch_etf.c b/net/sched/sch_etf.c
index c48f91075b5c..d96103b0e2bf 100644
--- a/net/sched/sch_etf.c
+++ b/net/sched/sch_etf.c
@@ -445,9 +445,6 @@ static void etf_reset(struct Qdisc *sch)
timesortedlist_clear(sch);
__qdisc_reset_queue(&sch->q);

- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
-
q->last = 0;
}

diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c
index d73393493553..8de4365886e8 100644
--- a/net/sched/sch_ets.c
+++ b/net/sched/sch_ets.c
@@ -727,8 +727,6 @@ static void ets_qdisc_reset(struct Qdisc *sch)
}
for (band = 0; band < q->nbands; band++)
qdisc_reset(q->classes[band].qdisc);
- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
}

static void ets_qdisc_destroy(struct Qdisc *sch)
diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index 839e1235db05..23a042adb74d 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -347,8 +347,6 @@ static void fq_codel_reset(struct Qdisc *sch)
codel_vars_init(&flow->cvars);
}
memset(q->backlogs, 0, q->flows_cnt * sizeof(u32));
- sch->q.qlen = 0;
- sch->qstats.backlog = 0;
q->memory_usage = 0;
}

diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c
index d6aba6edd16e..35c35465226b 100644
--- a/net/sched/sch_fq_pie.c
+++ b/net/sched/sch_fq_pie.c
@@ -521,9 +521,6 @@ static void fq_pie_reset(struct Qdisc *sch)
INIT_LIST_HEAD(&flow->flowchain);
pie_vars_init(&flow->vars);
}
-
- sch->q.qlen = 0;
- sch->qstats.backlog = 0;
}

static void fq_pie_destroy(struct Qdisc *sch)
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index d3979a6000e7..03efc40e42fc 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1484,8 +1484,6 @@ hfsc_reset_qdisc(struct Qdisc *sch)
}
q->eligible = RB_ROOT;
qdisc_watchdog_cancel(&q->watchdog);
- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
}

static void
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 23a9d6242429..cb5872d22ecf 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1008,8 +1008,6 @@ static void htb_reset(struct Qdisc *sch)
}
qdisc_watchdog_cancel(&q->watchdog);
__qdisc_reset_queue(&q->direct_queue);
- sch->q.qlen = 0;
- sch->qstats.backlog = 0;
memset(q->hlevel, 0, sizeof(q->hlevel));
memset(q->row_mask, 0, sizeof(q->row_mask));
}
diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index cd8ab90c4765..f28050c7f12d 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -152,7 +152,6 @@ multiq_reset(struct Qdisc *sch)

for (band = 0; band < q->bands; band++)
qdisc_reset(q->queues[band]);
- sch->q.qlen = 0;
q->curband = 0;
}

diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index 3b8d7197c06b..c03a11dd990f 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -135,8 +135,6 @@ prio_reset(struct Qdisc *sch)

for (prio = 0; prio < q->bands; prio++)
qdisc_reset(q->queues[prio]);
- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
}

static int prio_offload(struct Qdisc *sch, struct tc_prio_qopt *qopt)
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index d4ce58c90f9f..13246a9dc5c1 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -1458,8 +1458,6 @@ static void qfq_reset_qdisc(struct Qdisc *sch)
qdisc_reset(cl->qdisc);
}
}
- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
}

static void qfq_destroy_qdisc(struct Qdisc *sch)
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index 40adf1f07a82..f1e013e3f04a 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -176,8 +176,6 @@ static void red_reset(struct Qdisc *sch)
struct red_sched_data *q = qdisc_priv(sch);

qdisc_reset(q->qdisc);
- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
red_restart(&q->vars);
}

diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c
index 3d061a13d7ed..31717fa45a4f 100644
--- a/net/sched/sch_sfb.c
+++ b/net/sched/sch_sfb.c
@@ -453,8 +453,6 @@ static void sfb_reset(struct Qdisc *sch)
struct sfb_sched_data *q = qdisc_priv(sch);

qdisc_reset(q->qdisc);
- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
q->slot = 0;
q->double_buffering = false;
sfb_zero_all_buckets(q);
diff --git a/net/sched/sch_skbprio.c b/net/sched/sch_skbprio.c
index 7a5e4c454715..df72fb83d9c7 100644
--- a/net/sched/sch_skbprio.c
+++ b/net/sched/sch_skbprio.c
@@ -213,9 +213,6 @@ static void skbprio_reset(struct Qdisc *sch)
struct skbprio_sched_data *q = qdisc_priv(sch);
int prio;

- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
-
for (prio = 0; prio < SKBPRIO_MAX_PRIORITY; prio++)
__skb_queue_purge(&q->qdiscs[prio]);

diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 0b941dd63d26..db88a692ef81 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1636,8 +1636,6 @@ static void taprio_reset(struct Qdisc *sch)
if (q->qdiscs[i])
qdisc_reset(q->qdiscs[i]);
}
- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
}

static void taprio_destroy(struct Qdisc *sch)
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index 72102277449e..d0288e223542 100644
--- a/net/sched/sch_tbf.c
+++ b/net/sched/sch_tbf.c
@@ -330,8 +330,6 @@ static void tbf_reset(struct Qdisc *sch)
struct tbf_sched_data *q = qdisc_priv(sch);

qdisc_reset(q->qdisc);
- sch->qstats.backlog = 0;
- sch->q.qlen = 0;
q->t_c = ktime_get_ns();
q->tokens = q->buffer;
q->ptokens = q->mtu;
diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c
index 6af6b95bdb67..79aaab51cbf5 100644
--- a/net/sched/sch_teql.c
+++ b/net/sched/sch_teql.c
@@ -124,7 +124,6 @@ teql_reset(struct Qdisc *sch)
struct teql_sched_data *dat = qdisc_priv(sch);

skb_queue_purge(&dat->q);
- sch->q.qlen = 0;
}

static void
--
2.17.1


Hi Eric:
Thank you for your reply. I will modify changelog in v2.

Zhengchao Shao