Subject: [PATCH] NET : move Qdisc_class_ops and Qdisc_ops in appropriate sections

From: Eric Dumazet <[email-masked]>
Date: Wed, 14 Nov 2007 08:39:24 +0100

Hi David

Please find this patch against net-2.6.25

Thank you

[PATCH] NET : move Qdisc_class_ops and Qdisc_ops in appropriate sections

Qdisc_class_ops are const, and Qdisc_ops are mostly read.

Using "const" and "__read_mostly" qualifiers helps to reduce false sharing.

Signed-off-by: Eric Dumazet <[email-masked]>

  include/net/sch_generic.h |    2 +-
  net/mac80211/wme.c        |    4 ++--
  net/sched/cls_api.c       |    4 ++--
  net/sched/sch_api.c       |   12 ++++++------
  net/sched/sch_atm.c       |    4 ++--
  net/sched/sch_blackhole.c |    2 +-
  net/sched/sch_cbq.c       |    4 ++--
  net/sched/sch_dsmark.c    |    4 ++--
  net/sched/sch_fifo.c      |    4 ++--
  net/sched/sch_generic.c   |   10 +++++-----
  net/sched/sch_gred.c      |    2 +-
  net/sched/sch_hfsc.c      |    4 ++--
  net/sched/sch_htb.c       |    4 ++--
  net/sched/sch_ingress.c   |    4 ++--
  net/sched/sch_netem.c     |    6 +++---
  net/sched/sch_prio.c      |    6 +++---
  net/sched/sch_red.c       |    4 ++--
  net/sched/sch_sfq.c       |    2 +-
  net/sched/sch_tbf.c       |    4 ++--
  19 files changed, 43 insertions(+), 43 deletions(-)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index c926551..60b4b35 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -86,7 +86,7 @@ struct Qdisc_class_ops
 struct Qdisc_ops
 {
 	struct Qdisc_ops	*next;
-	struct Qdisc_class_ops	*cl_ops;
+	const struct Qdisc_class_ops	*cl_ops;
 	char			id[IFNAMSIZ];
 	int			priv_size;
 
diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c
index 5b8a157..8dbdede 100644
--- a/net/mac80211/wme.c
+++ b/net/mac80211/wme.c
@@ -527,7 +527,7 @@ static struct tcf_proto ** wme_classop_find_tcf(struct Qdisc *qd,
 
 /* this qdisc is classful (i.e. has classes, some of which may have leaf qdiscs attached)
  * - these are the operations on the classes */
-static struct Qdisc_class_ops class_ops =
+static const struct Qdisc_class_ops class_ops =
 {
 	.graft = wme_classop_graft,
 	.leaf = wme_classop_leaf,
@@ -547,7 +547,7 @@ static struct Qdisc_class_ops class_ops =

 /* queueing discipline operations */
-static struct Qdisc_ops wme_qdisc_ops =
+static struct Qdisc_ops wme_qdisc_ops __read_mostly =
 {
 	.next = NULL,
 	.cl_ops = &class_ops,
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 0365797..bb98045 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -130,7 +130,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 	struct tcf_proto **back, **chain;
 	struct tcf_proto *tp;
 	struct tcf_proto_ops *tp_ops;
-	struct Qdisc_class_ops *cops;
+	const struct Qdisc_class_ops *cops;
 	unsigned long cl;
 	unsigned long fh;
 	int err;
@@ -382,7 +382,7 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 	struct tcf_proto *tp, **chain;
 	struct tcmsg *tcm = (struct tcmsg*)NLMSG_DATA(cb->nlh);
 	unsigned long cl = 0;
-	struct Qdisc_class_ops *cops;
+	const struct Qdisc_class_ops *cops;
 	struct tcf_dump_args arg;
 
 	if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 8ae137e..259321b 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -195,7 +195,7 @@ static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
 {
 	unsigned long cl;
 	struct Qdisc *leaf;
-	struct Qdisc_class_ops *cops = p->ops->cl_ops;
+	const struct Qdisc_class_ops *cops = p->ops->cl_ops;
 
 	if (cops == NULL)
 		return NULL;
@@ -373,7 +373,7 @@ dev_graft_qdisc(struct net_device *dev, struct Qdisc *qdisc)
 
 void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
 {
-	struct Qdisc_class_ops *cops;
+	const struct Qdisc_class_ops *cops;
 	unsigned long cl;
 	u32 parentid;
 
@@ -417,7 +417,7 @@ static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
 			*old = dev_graft_qdisc(dev, new);
 		}
 	} else {
-		struct Qdisc_class_ops *cops = parent->ops->cl_ops;
+		const struct Qdisc_class_ops *cops = parent->ops->cl_ops;
 
 		err = -EINVAL;
 
@@ -581,7 +581,7 @@ static int
 check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
 {
 	struct Qdisc *leaf;
-	struct Qdisc_class_ops *cops = q->ops->cl_ops;
+	const struct Qdisc_class_ops *cops = q->ops->cl_ops;
 	struct check_loop_arg *arg = (struct check_loop_arg *)w;
 
 	leaf = cops->leaf(q, cl);
@@ -924,7 +924,7 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 	struct rtattr **tca = arg;
 	struct net_device *dev;
 	struct Qdisc *q = NULL;
-	struct Qdisc_class_ops *cops;
+	const struct Qdisc_class_ops *cops;
 	unsigned long cl = 0;
 	unsigned long new_cl;
 	u32 pid = tcm->tcm_parent;
@@ -1039,7 +1039,7 @@ static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q,
 	struct nlmsghdr  *nlh;
 	unsigned char *b = skb_tail_pointer(skb);
 	struct gnet_dump d;
-	struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
+	const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
 
 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
 	tcm = NLMSG_DATA(nlh);
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index ddc4f2c..d870a41 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -668,7 +668,7 @@ static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
 	return 0;
 }
 
-static struct Qdisc_class_ops atm_class_ops = {
+static const struct Qdisc_class_ops atm_class_ops = {
 	.graft		= atm_tc_graft,
 	.leaf		= atm_tc_leaf,
 	.get		= atm_tc_get,
@@ -683,7 +683,7 @@ static struct Qdisc_class_ops atm_class_ops = {
 	.dump_stats	= atm_tc_dump_class_stats,
 };
 
-static struct Qdisc_ops atm_qdisc_ops = {
+static struct Qdisc_ops atm_qdisc_ops __read_mostly = {
 	.cl_ops		= &atm_class_ops,
 	.id		= "atm",
 	.priv_size	= sizeof(struct atm_qdisc_data),
diff --git a/net/sched/sch_blackhole.c b/net/sched/sch_blackhole.c
index f914fc4..507fb48 100644
--- a/net/sched/sch_blackhole.c
+++ b/net/sched/sch_blackhole.c
@@ -28,7 +28,7 @@ static struct sk_buff *blackhole_dequeue(struct Qdisc *sch)
 	return NULL;
 }
 
-static struct Qdisc_ops blackhole_qdisc_ops = {
+static struct Qdisc_ops blackhole_qdisc_ops __read_mostly = {
 	.id		= "blackhole",
 	.priv_size	= 0,
 	.enqueue	= blackhole_enqueue,
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 4de3744..bea123f 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -2045,7 +2045,7 @@ static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 	}
 }
 
-static struct Qdisc_class_ops cbq_class_ops = {
+static const struct Qdisc_class_ops cbq_class_ops = {
 	.graft		=	cbq_graft,
 	.leaf		=	cbq_leaf,
 	.qlen_notify	=	cbq_qlen_notify,
@@ -2061,7 +2061,7 @@ static struct Qdisc_class_ops cbq_class_ops = {
 	.dump_stats	=	cbq_dump_class_stats,
 };
 
-static struct Qdisc_ops cbq_qdisc_ops = {
+static struct Qdisc_ops cbq_qdisc_ops __read_mostly = {
 	.next		=	NULL,
 	.cl_ops		=	&cbq_class_ops,
 	.id		=	"cbq",
diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
index 60f8919..b9fe697 100644
--- a/net/sched/sch_dsmark.c
+++ b/net/sched/sch_dsmark.c
@@ -461,7 +461,7 @@ rtattr_failure:
 	return RTA_NEST_CANCEL(skb, opts);
 }
 
-static struct Qdisc_class_ops dsmark_class_ops = {
+static const struct Qdisc_class_ops dsmark_class_ops = {
 	.graft		=	dsmark_graft,
 	.leaf		=	dsmark_leaf,
 	.get		=	dsmark_get,
@@ -475,7 +475,7 @@ static struct Qdisc_class_ops dsmark_class_ops = {
 	.dump		=	dsmark_dump_class,
 };
 
-static struct Qdisc_ops dsmark_qdisc_ops = {
+static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
 	.next		=	NULL,
 	.cl_ops		=	&dsmark_class_ops,
 	.id		=	"dsmark",
diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c
index c264308..d71dbfc 100644
--- a/net/sched/sch_fifo.c
+++ b/net/sched/sch_fifo.c
@@ -78,7 +78,7 @@ rtattr_failure:
 	return -1;
 }
 
-struct Qdisc_ops pfifo_qdisc_ops = {
+struct Qdisc_ops pfifo_qdisc_ops __read_mostly = {
 	.id		=	"pfifo",
 	.priv_size	=	sizeof(struct fifo_sched_data),
 	.enqueue	=	pfifo_enqueue,
@@ -92,7 +92,7 @@ struct Qdisc_ops pfifo_qdisc_ops = {
 	.owner		=	THIS_MODULE,
 };
 
-struct Qdisc_ops bfifo_qdisc_ops = {
+struct Qdisc_ops bfifo_qdisc_ops __read_mostly = {
 	.id		=	"bfifo",
 	.priv_size	=	sizeof(struct fifo_sched_data),
 	.enqueue	=	bfifo_enqueue,
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 7f49620..4f019c2 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -286,7 +286,7 @@ static int noop_requeue(struct sk_buff *skb, struct Qdisc* qdisc)
 	return NET_XMIT_CN;
 }
 
-struct Qdisc_ops noop_qdisc_ops = {
+struct Qdisc_ops noop_qdisc_ops __read_mostly = {
 	.id		=	"noop",
 	.priv_size	=	0,
 	.enqueue	=	noop_enqueue,
@@ -303,7 +303,7 @@ struct Qdisc noop_qdisc = {
 	.list		=	LIST_HEAD_INIT(noop_qdisc.list),
 };
 
-static struct Qdisc_ops noqueue_qdisc_ops = {
+static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
 	.id		=	"noqueue",
 	.priv_size	=	0,
 	.enqueue	=	noop_enqueue,
@@ -405,7 +405,7 @@ static int pfifo_fast_init(struct Qdisc *qdisc, struct rtattr *opt)
 	return 0;
 }
 
-static struct Qdisc_ops pfifo_fast_ops = {
+static struct Qdisc_ops pfifo_fast_ops __read_mostly = {
 	.id		=	"pfifo_fast",
 	.priv_size	=	PFIFO_FAST_BANDS * sizeof(struct sk_buff_head),
 	.enqueue	=	pfifo_fast_enqueue,
@@ -471,7 +471,7 @@ errout:
 
 void qdisc_reset(struct Qdisc *qdisc)
 {
-	struct Qdisc_ops *ops = qdisc->ops;
+	const struct Qdisc_ops *ops = qdisc->ops;
 
 	if (ops->reset)
 		ops->reset(qdisc);
@@ -490,7 +490,7 @@ static void __qdisc_destroy(struct rcu_head *head)
 
 void qdisc_destroy(struct Qdisc *qdisc)
 {
-	struct Qdisc_ops  *ops = qdisc->ops;
+	const struct Qdisc_ops  *ops = qdisc->ops;
 
 	if (qdisc->flags & TCQ_F_BUILTIN ||
 	    !atomic_dec_and_test(&qdisc->refcnt))
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index 3cc6dda..e2bcd66 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -577,7 +577,7 @@ static void gred_destroy(struct Qdisc *sch)
 	}
 }
 
-static struct Qdisc_ops gred_qdisc_ops = {
+static struct Qdisc_ops gred_qdisc_ops __read_mostly = {
 	.id		=	"gred",
 	.priv_size	=	sizeof(struct gred_sched),
 	.enqueue	=	gred_enqueue,
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 55e7e45..ff03327 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1698,7 +1698,7 @@ hfsc_drop(struct Qdisc *sch)
 	return 0;
 }
 
-static struct Qdisc_class_ops hfsc_class_ops = {
+static const struct Qdisc_class_ops hfsc_class_ops = {
 	.change		= hfsc_change_class,
 	.delete		= hfsc_delete_class,
 	.graft		= hfsc_graft_class,
@@ -1714,7 +1714,7 @@ static struct Qdisc_class_ops hfsc_class_ops = {
 	.walk		= hfsc_walk
 };
 
-static struct Qdisc_ops hfsc_qdisc_ops = {
+static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
 	.id		= "hfsc",
 	.init		= hfsc_init_qdisc,
 	.change		= hfsc_change_qdisc,
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 5e608a6..72beb66 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1529,7 +1529,7 @@ static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 	}
 }
 
-static struct Qdisc_class_ops htb_class_ops = {
+static const struct Qdisc_class_ops htb_class_ops = {
 	.graft		=	htb_graft,
 	.leaf		=	htb_leaf,
 	.qlen_notify	=	htb_qlen_notify,
@@ -1545,7 +1545,7 @@ static struct Qdisc_class_ops htb_class_ops = {
 	.dump_stats	=	htb_dump_class_stats,
 };
 
-static struct Qdisc_ops htb_qdisc_ops = {
+static struct Qdisc_ops htb_qdisc_ops __read_mostly = {
 	.next		=	NULL,
 	.cl_ops		=	&htb_class_ops,
 	.id		=	"htb",
diff --git a/net/sched/sch_ingress.c b/net/sched/sch_ingress.c
index 3f8335e..05d2bb7 100644
--- a/net/sched/sch_ingress.c
+++ b/net/sched/sch_ingress.c
@@ -338,7 +338,7 @@ rtattr_failure:
 	return -1;
 }
 
-static struct Qdisc_class_ops ingress_class_ops = {
+static const struct Qdisc_class_ops ingress_class_ops = {
 	.graft		=	ingress_graft,
 	.leaf		=	ingress_leaf,
 	.get		=	ingress_get,
@@ -352,7 +352,7 @@ static struct Qdisc_class_ops ingress_class_ops = {
 	.dump		=	NULL,
 };
 
-static struct Qdisc_ops ingress_qdisc_ops = {
+static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
 	.next		=	NULL,
 	.cl_ops		=	&ingress_class_ops,
 	.id		=	"ingress",
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 9e5e87e..6c344ad 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -544,7 +544,7 @@ rtattr_failure:
 	return -1;
 }
 
-static struct Qdisc_ops tfifo_qdisc_ops = {
+static struct Qdisc_ops tfifo_qdisc_ops __read_mostly = {
 	.id		=	"tfifo",
 	.priv_size	=	sizeof(struct fifo_sched_data),
 	.enqueue	=	tfifo_enqueue,
@@ -705,7 +705,7 @@ static struct tcf_proto **netem_find_tcf(struct Qdisc *sch, unsigned long cl)
 	return NULL;
 }
 
-static struct Qdisc_class_ops netem_class_ops = {
+static const struct Qdisc_class_ops netem_class_ops = {
 	.graft		=	netem_graft,
 	.leaf		=	netem_leaf,
 	.get		=	netem_get,
@@ -717,7 +717,7 @@ static struct Qdisc_class_ops netem_class_ops = {
 	.dump		=	netem_dump_class,
 };
 
-static struct Qdisc_ops netem_qdisc_ops = {
+static struct Qdisc_ops netem_qdisc_ops __read_mostly = {
 	.id		=	"netem",
 	.cl_ops		=	&netem_class_ops,
 	.priv_size	=	sizeof(struct netem_sched_data),
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index de89409..2243aaa 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -468,7 +468,7 @@ static struct tcf_proto ** prio_find_tcf(struct Qdisc *sch, unsigned long cl)
 	return &q->filter_list;
 }
 
-static struct Qdisc_class_ops prio_class_ops = {
+static const struct Qdisc_class_ops prio_class_ops = {
 	.graft		=	prio_graft,
 	.leaf		=	prio_leaf,
 	.get		=	prio_get,
@@ -483,7 +483,7 @@ static struct Qdisc_class_ops prio_class_ops = {
 	.dump_stats	=	prio_dump_class_stats,
 };
 
-static struct Qdisc_ops prio_qdisc_ops = {
+static struct Qdisc_ops prio_qdisc_ops __read_mostly = {
 	.next		=	NULL,
 	.cl_ops		=	&prio_class_ops,
 	.id		=	"prio",
@@ -500,7 +500,7 @@ static struct Qdisc_ops prio_qdisc_ops = {
 	.owner		=	THIS_MODULE,
 };
 
-static struct Qdisc_ops rr_qdisc_ops = {
+static struct Qdisc_ops rr_qdisc_ops __read_mostly = {
 	.next		=	NULL,
 	.cl_ops		=	&prio_class_ops,
 	.id		=	"rr",
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index 9b95fef..f1e9647 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -359,7 +359,7 @@ static struct tcf_proto **red_find_tcf(struct Qdisc *sch, unsigned long cl)
 	return NULL;
 }
 
-static struct Qdisc_class_ops red_class_ops = {
+static const struct Qdisc_class_ops red_class_ops = {
 	.graft		=	red_graft,
 	.leaf		=	red_leaf,
 	.get		=	red_get,
@@ -371,7 +371,7 @@ static struct Qdisc_class_ops red_class_ops = {
 	.dump		=	red_dump_class,
 };
 
-static struct Qdisc_ops red_qdisc_ops = {
+static struct Qdisc_ops red_qdisc_ops __read_mostly = {
 	.id		=	"red",
 	.priv_size	=	sizeof(struct red_sched_data),
 	.cl_ops		=	&red_class_ops,
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 6529387..c58fa6e 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -480,7 +480,7 @@ rtattr_failure:
 	return -1;
 }
 
-static struct Qdisc_ops sfq_qdisc_ops = {
+static struct Qdisc_ops sfq_qdisc_ops __read_mostly = {
 	.next		=	NULL,
 	.cl_ops		=	NULL,
 	.id		=	"sfq",
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index b0d8109..d88fea9 100644
--- a/net/sched/sch_tbf.c
+++ b/net/sched/sch_tbf.c
@@ -469,7 +469,7 @@ static struct tcf_proto **tbf_find_tcf(struct Qdisc *sch, unsigned long cl)
 	return NULL;
 }
 
-static struct Qdisc_class_ops tbf_class_ops =
+static const struct Qdisc_class_ops tbf_class_ops =
 {
 	.graft		=	tbf_graft,
 	.leaf		=	tbf_leaf,
@@ -482,7 +482,7 @@ static struct Qdisc_class_ops tbf_class_ops =
 	.dump		=	tbf_dump_class,
 };
 
-static struct Qdisc_ops tbf_qdisc_ops = {
+static struct Qdisc_ops tbf_qdisc_ops __read_mostly = {
 	.next		=	NULL,
 	.cl_ops		=	&tbf_class_ops,
 	.id		=	"tbf",