![stephen hemminger](/assets/img/avatar_default.png)
By default, the pfifo_fast queue discipline has been used by default for all devices. But we have better choices now. This patch allow setting the default queueing discipline with sysctl. This allows easy use of better queueing disciplines on all devices without having to use tc qdisc scripts. It is intended to allow an easy path for distributions to make fq_codel or sfq the default qdisc. This patch also makes pfifo_fast more of a first class qdisc, since it is now possible to manually override the default and explicitly use pfifo_fast. The behavior for systems who do not use the sysctl is unchanged, they still get pfifo_fast Also removes leftover random # in sysctl net core. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
244 lines
5.7 KiB
C
244 lines
5.7 KiB
C
/*
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* net/sched/sch_mq.c Classful multiqueue dummy scheduler
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*
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* Copyright (c) 2009 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/skbuff.h>
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#include <net/netlink.h>
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#include <net/pkt_sched.h>
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struct mq_sched {
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struct Qdisc **qdiscs;
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};
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static void mq_destroy(struct Qdisc *sch)
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{
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struct net_device *dev = qdisc_dev(sch);
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struct mq_sched *priv = qdisc_priv(sch);
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unsigned int ntx;
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if (!priv->qdiscs)
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return;
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for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++)
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qdisc_destroy(priv->qdiscs[ntx]);
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kfree(priv->qdiscs);
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}
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static int mq_init(struct Qdisc *sch, struct nlattr *opt)
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{
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struct net_device *dev = qdisc_dev(sch);
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struct mq_sched *priv = qdisc_priv(sch);
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struct netdev_queue *dev_queue;
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struct Qdisc *qdisc;
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unsigned int ntx;
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if (sch->parent != TC_H_ROOT)
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return -EOPNOTSUPP;
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if (!netif_is_multiqueue(dev))
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return -EOPNOTSUPP;
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/* pre-allocate qdiscs, attachment can't fail */
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priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]),
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GFP_KERNEL);
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if (priv->qdiscs == NULL)
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return -ENOMEM;
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for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
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dev_queue = netdev_get_tx_queue(dev, ntx);
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qdisc = qdisc_create_dflt(dev_queue, default_qdisc_ops,
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TC_H_MAKE(TC_H_MAJ(sch->handle),
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TC_H_MIN(ntx + 1)));
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if (qdisc == NULL)
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goto err;
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priv->qdiscs[ntx] = qdisc;
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qdisc->flags |= TCQ_F_ONETXQUEUE;
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}
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sch->flags |= TCQ_F_MQROOT;
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return 0;
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err:
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mq_destroy(sch);
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return -ENOMEM;
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}
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static void mq_attach(struct Qdisc *sch)
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{
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struct net_device *dev = qdisc_dev(sch);
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struct mq_sched *priv = qdisc_priv(sch);
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struct Qdisc *qdisc;
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unsigned int ntx;
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for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
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qdisc = priv->qdiscs[ntx];
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qdisc = dev_graft_qdisc(qdisc->dev_queue, qdisc);
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if (qdisc)
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qdisc_destroy(qdisc);
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}
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kfree(priv->qdiscs);
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priv->qdiscs = NULL;
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}
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static int mq_dump(struct Qdisc *sch, struct sk_buff *skb)
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{
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struct net_device *dev = qdisc_dev(sch);
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struct Qdisc *qdisc;
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unsigned int ntx;
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sch->q.qlen = 0;
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memset(&sch->bstats, 0, sizeof(sch->bstats));
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memset(&sch->qstats, 0, sizeof(sch->qstats));
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for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
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qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping;
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spin_lock_bh(qdisc_lock(qdisc));
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sch->q.qlen += qdisc->q.qlen;
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sch->bstats.bytes += qdisc->bstats.bytes;
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sch->bstats.packets += qdisc->bstats.packets;
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sch->qstats.qlen += qdisc->qstats.qlen;
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sch->qstats.backlog += qdisc->qstats.backlog;
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sch->qstats.drops += qdisc->qstats.drops;
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sch->qstats.requeues += qdisc->qstats.requeues;
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sch->qstats.overlimits += qdisc->qstats.overlimits;
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spin_unlock_bh(qdisc_lock(qdisc));
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}
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return 0;
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}
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static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl)
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{
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struct net_device *dev = qdisc_dev(sch);
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unsigned long ntx = cl - 1;
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if (ntx >= dev->num_tx_queues)
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return NULL;
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return netdev_get_tx_queue(dev, ntx);
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}
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static struct netdev_queue *mq_select_queue(struct Qdisc *sch,
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struct tcmsg *tcm)
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{
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unsigned int ntx = TC_H_MIN(tcm->tcm_parent);
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struct netdev_queue *dev_queue = mq_queue_get(sch, ntx);
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if (!dev_queue) {
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struct net_device *dev = qdisc_dev(sch);
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return netdev_get_tx_queue(dev, 0);
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}
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return dev_queue;
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}
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static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,
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struct Qdisc **old)
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{
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struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
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struct net_device *dev = qdisc_dev(sch);
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if (dev->flags & IFF_UP)
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dev_deactivate(dev);
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*old = dev_graft_qdisc(dev_queue, new);
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if (new)
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new->flags |= TCQ_F_ONETXQUEUE;
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if (dev->flags & IFF_UP)
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dev_activate(dev);
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return 0;
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}
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static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl)
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{
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struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
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return dev_queue->qdisc_sleeping;
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}
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static unsigned long mq_get(struct Qdisc *sch, u32 classid)
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{
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unsigned int ntx = TC_H_MIN(classid);
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if (!mq_queue_get(sch, ntx))
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return 0;
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return ntx;
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}
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static void mq_put(struct Qdisc *sch, unsigned long cl)
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{
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}
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static int mq_dump_class(struct Qdisc *sch, unsigned long cl,
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struct sk_buff *skb, struct tcmsg *tcm)
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{
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struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
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tcm->tcm_parent = TC_H_ROOT;
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tcm->tcm_handle |= TC_H_MIN(cl);
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tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
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return 0;
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}
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static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
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struct gnet_dump *d)
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{
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struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
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sch = dev_queue->qdisc_sleeping;
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sch->qstats.qlen = sch->q.qlen;
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if (gnet_stats_copy_basic(d, &sch->bstats) < 0 ||
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gnet_stats_copy_queue(d, &sch->qstats) < 0)
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return -1;
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return 0;
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}
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static void mq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
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{
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struct net_device *dev = qdisc_dev(sch);
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unsigned int ntx;
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if (arg->stop)
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return;
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arg->count = arg->skip;
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for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
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if (arg->fn(sch, ntx + 1, arg) < 0) {
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arg->stop = 1;
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break;
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}
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arg->count++;
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}
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}
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static const struct Qdisc_class_ops mq_class_ops = {
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.select_queue = mq_select_queue,
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.graft = mq_graft,
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.leaf = mq_leaf,
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.get = mq_get,
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.put = mq_put,
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.walk = mq_walk,
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.dump = mq_dump_class,
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.dump_stats = mq_dump_class_stats,
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};
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struct Qdisc_ops mq_qdisc_ops __read_mostly = {
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.cl_ops = &mq_class_ops,
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.id = "mq",
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.priv_size = sizeof(struct mq_sched),
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.init = mq_init,
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.destroy = mq_destroy,
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.attach = mq_attach,
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.dump = mq_dump,
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.owner = THIS_MODULE,
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};
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