From dd47c1fa776cda48531b651c88341e951140b0a7 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 9 Jun 2016 00:27:40 +0200 Subject: cbq: remove TCA_CBQ_POLICE support iproute2 doesn't implement any cbq option that results in this attribute being sent to kernel. To make use of it, user would have to - patch iproute2 - add a class - attach a qdisc to the class (default pfifo doesn't work as q->handle is 0 and cbq_set_police() is a no-op in this case) - re-'add' the same class (tc class change ...) again - user must also specifiy a defmap (e.g. 'split 1:0 defmap 3f'), since this 'police' feature relies on its presence - the added qdisc must be one of bfifo, pfifo or netem If all of these conditions are met and _some_ leaf qdiscs, namely p/bfifo, netem, plug or tbf would drop a packet, kernel calls back into cbq, which will attempt to re-queue the skb into a different class as indicated by the parents' defmap entry for TC_PRIO_BESTEFFORT. [ i.e. we behave as if tc_classify returned TC_ACT_RECLASSIFY ]. This feature, which isn't documented or implemented in iproute2, and isn't implemented consistently (most qdiscs like sfq, codel, etc drop right away instead of attempting this reclassification) is the sole reason for the reshape_fail and __parent member in Qdisc struct. So remove TCA_CBQ_POLICE support from the kernel, reject it via EOPNOTSUPP so userspace knows we don't support it, and then remove no-longer needed infrastructure in followup commit. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- include/net/sch_generic.h | 4 ---- 1 file changed, 4 deletions(-) (limited to 'include') diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index c4f5749342ec..c069ac1dd75d 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -68,10 +68,6 @@ struct Qdisc { void *u32_node; - /* This field is deprecated, but it is still used by CBQ - * and it will live until better solution will be invented. - */ - struct Qdisc *__parent; struct netdev_queue *dev_queue; struct gnet_stats_rate_est64 rate_est; -- cgit v1.2.3 From c3a173d7dba2d7c74dd4ab871b8f22bf56ac10b2 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 9 Jun 2016 00:27:41 +0200 Subject: sched: remove qdisc_rehape_fail After the removal of TCA_CBQ_POLICE in cbq scheduler qdisc->reshape_fail is always NULL, i.e. qdisc_rehape_fail is now the same as qdisc_drop. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- include/net/sch_generic.h | 19 ------------------- 1 file changed, 19 deletions(-) (limited to 'include') diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index c069ac1dd75d..a9aec633d467 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -63,9 +63,6 @@ struct Qdisc { struct list_head list; u32 handle; u32 parent; - int (*reshape_fail)(struct sk_buff *skb, - struct Qdisc *q); - void *u32_node; struct netdev_queue *dev_queue; @@ -771,22 +768,6 @@ static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) return NET_XMIT_DROP; } -static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch) -{ - qdisc_qstats_drop(sch); - -#ifdef CONFIG_NET_CLS_ACT - if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch)) - goto drop; - - return NET_XMIT_SUCCESS; - -drop: -#endif - kfree_skb(skb); - return NET_XMIT_DROP; -} - /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how long it will take to send a packet given its size. */ -- cgit v1.2.3 From a09ceb0e08140a1eec05b49b4c232d3481339cb0 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 9 Jun 2016 00:27:42 +0200 Subject: sched: remove qdisc->drop after removal of TCA_CBQ_OVL_STRATEGY from cbq scheduler, there are no more callers of ->drop() outside of other ->drop functions, i.e. nothing calls them. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- include/net/sch_generic.h | 36 ------------------------------------ 1 file changed, 36 deletions(-) (limited to 'include') diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index a9aec633d467..4dedb7f12ed5 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -174,7 +174,6 @@ struct Qdisc_ops { int (*enqueue)(struct sk_buff *, struct Qdisc *); struct sk_buff * (*dequeue)(struct Qdisc *); struct sk_buff * (*peek)(struct Qdisc *); - unsigned int (*drop)(struct Qdisc *); int (*init)(struct Qdisc *, struct nlattr *arg); void (*reset)(struct Qdisc *); @@ -658,22 +657,6 @@ static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch) return __qdisc_queue_drop_head(sch, &sch->q); } -static inline struct sk_buff *__qdisc_dequeue_tail(struct Qdisc *sch, - struct sk_buff_head *list) -{ - struct sk_buff *skb = __skb_dequeue_tail(list); - - if (likely(skb != NULL)) - qdisc_qstats_backlog_dec(sch, skb); - - return skb; -} - -static inline struct sk_buff *qdisc_dequeue_tail(struct Qdisc *sch) -{ - return __qdisc_dequeue_tail(sch, &sch->q); -} - static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch) { return skb_peek(&sch->q); @@ -741,25 +724,6 @@ static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new, return old; } -static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch, - struct sk_buff_head *list) -{ - struct sk_buff *skb = __qdisc_dequeue_tail(sch, list); - - if (likely(skb != NULL)) { - unsigned int len = qdisc_pkt_len(skb); - kfree_skb(skb); - return len; - } - - return 0; -} - -static inline unsigned int qdisc_queue_drop(struct Qdisc *sch) -{ - return __qdisc_queue_drop(sch, &sch->q); -} - static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) { kfree_skb(skb); -- cgit v1.2.3 From c8945043cdc687388b7a43fc6f474bddd9607e80 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 9 Jun 2016 00:27:43 +0200 Subject: sched: place state, next_sched and gso_skb in same cacheline again Earlier commits removed two members from struct Qdisc which places next_sched/gso_skb into a different cacheline than ->state. This restores the struct layout to what it was before the removal. Move the two members, then add an annotation so they all reside in the same cacheline. This adds a 16 byte hole after cpu_qstats. The hole could be closed but as it doesn't decrease total struct size just do it this way. Reported-by: Eric Dumazet Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- include/net/sch_generic.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 4dedb7f12ed5..49534e28824b 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -71,11 +71,11 @@ struct Qdisc { struct gnet_stats_basic_cpu __percpu *cpu_bstats; struct gnet_stats_queue __percpu *cpu_qstats; - struct Qdisc *next_sched; - struct sk_buff *gso_skb; /* * For performance sake on SMP, we put highly modified fields at the end */ + struct Qdisc *next_sched ____cacheline_aligned_in_smp; + struct sk_buff *gso_skb; unsigned long state; struct sk_buff_head q; struct gnet_stats_basic_packed bstats; -- cgit v1.2.3