From: Eric Dumazet Date: Thu, 3 Mar 2011 19:10:02 +0000 (-0800) Subject: net_sched: reduce fifo qdisc size X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d276055c4e90a7278cd5167ba9755c9b214bcff7;p=linux-beck.git net_sched: reduce fifo qdisc size Because of various alignements [SLUB / qdisc], we use 512 bytes of memory for one {p|b}fifo qdisc, instead of 256 bytes on 64bit arches and 192 bytes on 32bit ones. Move the "u32 limit" inside "struct Qdisc" (no impact on other qdiscs) Change qdisc_alloc(), first trying a regular allocation before an oversized one. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 16626a04cb03..1934634f8896 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -83,6 +83,7 @@ struct Qdisc { struct gnet_stats_queue qstats; struct rcu_head rcu_head; spinlock_t busylock; + u32 limit; }; static inline bool qdisc_is_running(const struct Qdisc *qdisc) diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c index be33f9ddf9dd..66effe2da8e0 100644 --- a/net/sched/sch_fifo.c +++ b/net/sched/sch_fifo.c @@ -19,15 +19,9 @@ /* 1 band FIFO pseudo-"scheduler" */ -struct fifo_sched_data { - u32 limit; -}; - static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch) { - struct fifo_sched_data *q = qdisc_priv(sch); - - if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <= q->limit)) + if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <= sch->limit)) return qdisc_enqueue_tail(skb, sch); return qdisc_reshape_fail(skb, sch); @@ -35,9 +29,7 @@ static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch) static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch) { - struct fifo_sched_data *q = qdisc_priv(sch); - - if (likely(skb_queue_len(&sch->q) < q->limit)) + if (likely(skb_queue_len(&sch->q) < sch->limit)) return qdisc_enqueue_tail(skb, sch); return qdisc_reshape_fail(skb, sch); @@ -45,9 +37,7 @@ static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch) static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch) { - struct fifo_sched_data *q = qdisc_priv(sch); - - if (likely(skb_queue_len(&sch->q) < q->limit)) + if (likely(skb_queue_len(&sch->q) < sch->limit)) return qdisc_enqueue_tail(skb, sch); /* queue full, remove one skb to fulfill the limit */ @@ -60,7 +50,6 @@ static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch) static int fifo_init(struct Qdisc *sch, struct nlattr *opt) { - struct fifo_sched_data *q = qdisc_priv(sch); bool bypass; bool is_bfifo = sch->ops == &bfifo_qdisc_ops; @@ -70,20 +59,20 @@ static int fifo_init(struct Qdisc *sch, struct nlattr *opt) if (is_bfifo) limit *= psched_mtu(qdisc_dev(sch)); - q->limit = limit; + sch->limit = limit; } else { struct tc_fifo_qopt *ctl = nla_data(opt); if (nla_len(opt) < sizeof(*ctl)) return -EINVAL; - q->limit = ctl->limit; + sch->limit = ctl->limit; } if (is_bfifo) - bypass = q->limit >= psched_mtu(qdisc_dev(sch)); + bypass = sch->limit >= psched_mtu(qdisc_dev(sch)); else - bypass = q->limit >= 1; + bypass = sch->limit >= 1; if (bypass) sch->flags |= TCQ_F_CAN_BYPASS; @@ -94,8 +83,7 @@ static int fifo_init(struct Qdisc *sch, struct nlattr *opt) static int fifo_dump(struct Qdisc *sch, struct sk_buff *skb) { - struct fifo_sched_data *q = qdisc_priv(sch); - struct tc_fifo_qopt opt = { .limit = q->limit }; + struct tc_fifo_qopt opt = { .limit = sch->limit }; NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); return skb->len; @@ -106,7 +94,7 @@ nla_put_failure: struct Qdisc_ops pfifo_qdisc_ops __read_mostly = { .id = "pfifo", - .priv_size = sizeof(struct fifo_sched_data), + .priv_size = 0, .enqueue = pfifo_enqueue, .dequeue = qdisc_dequeue_head, .peek = qdisc_peek_head, @@ -121,7 +109,7 @@ EXPORT_SYMBOL(pfifo_qdisc_ops); struct Qdisc_ops bfifo_qdisc_ops __read_mostly = { .id = "bfifo", - .priv_size = sizeof(struct fifo_sched_data), + .priv_size = 0, .enqueue = bfifo_enqueue, .dequeue = qdisc_dequeue_head, .peek = qdisc_peek_head, @@ -136,7 +124,7 @@ EXPORT_SYMBOL(bfifo_qdisc_ops); struct Qdisc_ops pfifo_head_drop_qdisc_ops __read_mostly = { .id = "pfifo_head_drop", - .priv_size = sizeof(struct fifo_sched_data), + .priv_size = 0, .enqueue = pfifo_tail_enqueue, .dequeue = qdisc_dequeue_head, .peek = qdisc_peek_head, diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 0da09d508737..a854cab03f1e 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -550,21 +550,25 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, { void *p; struct Qdisc *sch; - unsigned int size; + unsigned int size = QDISC_ALIGN(sizeof(*sch)) + ops->priv_size; int err = -ENOBUFS; - /* ensure that the Qdisc and the private data are 64-byte aligned */ - size = QDISC_ALIGN(sizeof(*sch)); - size += ops->priv_size + (QDISC_ALIGNTO - 1); - p = kzalloc_node(size, GFP_KERNEL, netdev_queue_numa_node_read(dev_queue)); if (!p) goto errout; sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p); - sch->padded = (char *) sch - (char *) p; - + /* if we got non aligned memory, ask more and do alignment ourself */ + if (sch != p) { + kfree(p); + p = kzalloc_node(size + QDISC_ALIGNTO - 1, GFP_KERNEL, + netdev_queue_numa_node_read(dev_queue)); + if (!p) + goto errout; + sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p); + sch->padded = (char *) sch - (char *) p; + } INIT_LIST_HEAD(&sch->list); skb_queue_head_init(&sch->q); spin_lock_init(&sch->busylock);