--- /dev/null
+From: Hannes Reinecke <hare@suse.de>
+Date: Wed, 17 Sep 2008 16:45:55 +0200
+Subject: pkt_sched: Add multiqueue scheduler support
+References: FATE#303913
+
+This patch is intended to add a qdisc to support the new tx multiqueue
+architecture by providing a band for each hardware queue. By doing
+this it is possible to support a different qdisc per physical hardware
+queue.
+
+This qdisc uses the skb->queue_mapping to select which band to place
+the traffic onto. It then uses a round robin w/ a check to see if the
+subqueue is stopped to determine which band to dequeue the packet from.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
+Signed-off-by: Hannes Reinecke <hare@suse.de>
+---
+ Documentation/networking/multiqueue.txt | 47 +++-
+ include/linux/pkt_sched.h | 7 +
+ net/sched/Kconfig | 9 +
+ net/sched/Makefile | 1 +
+ net/sched/sch_multiq.c | 469 +++++++++++++++++++++++++++++++
+ 5 files changed, 532 insertions(+), 1 deletions(-)
+ create mode 100644 net/sched/sch_multiq.c
+
+diff --git a/Documentation/networking/multiqueue.txt b/Documentation/networking/multiqueue.txt
+index d391ea6..5787ee6 100644
+--- a/Documentation/networking/multiqueue.txt
++++ b/Documentation/networking/multiqueue.txt
+@@ -24,4 +24,49 @@ netif_{start|stop|wake}_subqueue() functions to manage each queue while the
+ device is still operational. netdev->queue_lock is still used when the device
+ comes online or when it's completely shut down (unregister_netdev(), etc.).
+
+-Author: Peter P. Waskiewicz Jr. <peter.p.waskiewicz.jr@intel.com>
++
++Section 2: Qdisc support for multiqueue devices
++
++-----------------------------------------------
++
++Currently two qdiscs support multiqueue devices. The first is the default
++pfifo_fast qdisc. This qdisc supports one qdisc per hardware queue. A new
++round-robin qdisc, sch_multiq also supports multiple hardware queues. The
++qdisc is responsible for classifying the skb's and then directing the skb's to
++bands and queues based on the value in skb->queue_mapping. Use this field in
++the base driver to determine which queue to send the skb to.
++
++sch_multiq has been added for hardware that wishes to avoid unnecessary
++requeuing. It will cycle though the bands and verify that the hardware queue
++associated with the band is not stopped prior to dequeuing a packet.
++
++On qdisc load, the number of bands is based on the number of queues on the
++hardware. Once the association is made, any skb with skb->queue_mapping set,
++will be queued to the band associated with the hardware queue.
++
++
++Section 3: Brief howto using MULTIQ for multiqueue devices
++---------------------------------------------------------------
++
++The userspace command 'tc,' part of the iproute2 package, is used to configure
++qdiscs. To add the MULTIQ qdisc to your network device, assuming the device
++is called eth0, run the following command:
++
++# tc qdisc add dev eth0 root handle 1: multiq
++
++The qdisc will allocate the number of bands to equal the number of queues that
++the device reports, and bring the qdisc online. Assuming eth0 has 4 Tx
++queues, the band mapping would look like:
++
++band 0 => queue 0
++band 1 => queue 1
++band 2 => queue 2
++band 3 => queue 3
++
++Traffic will begin flowing through each queue if your base device has either
++the default simple_tx_hash or a custom netdev->select_queue() defined.
++
++The behavior of tc filters remains the same.
++
++Author: Alexander Duyck <alexander.h.duyck@intel.com>
++Original Author: Peter P. Waskiewicz Jr. <peter.p.waskiewicz.jr@intel.com>
+diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
+index e5de421..5d921fa 100644
+--- a/include/linux/pkt_sched.h
++++ b/include/linux/pkt_sched.h
+@@ -123,6 +123,13 @@ struct tc_prio_qopt
+ __u8 priomap[TC_PRIO_MAX+1]; /* Map: logical priority -> PRIO band */
+ };
+
++/* MULTIQ section */
++
++struct tc_multiq_qopt {
++ __u16 bands; /* Number of bands */
++ __u16 max_bands; /* Maximum number of queues */
++};
++
+ /* TBF section */
+
+ struct tc_tbf_qopt
+diff --git a/net/sched/Kconfig b/net/sched/Kconfig
+index 9437b27..efaa7a7 100644
+--- a/net/sched/Kconfig
++++ b/net/sched/Kconfig
+@@ -106,6 +106,15 @@ config NET_SCH_PRIO
+ To compile this code as a module, choose M here: the
+ module will be called sch_prio.
+
++config NET_SCH_MULTIQ
++ tristate "Hardware Multiqueue-aware Multi Band Queuing (MULTIQ)"
++ ---help---
++ Say Y here if you want to use an n-band queue packet scheduler
++ to support devices that have multiple hardware transmit queues.
++
++ To compile this code as a module, choose M here: the
++ module will be called sch_multiq.
++
+ config NET_SCH_RED
+ tristate "Random Early Detection (RED)"
+ ---help---
+diff --git a/net/sched/Makefile b/net/sched/Makefile
+index 1d2b0f7..3d9b953 100644
+--- a/net/sched/Makefile
++++ b/net/sched/Makefile
+@@ -26,6 +26,7 @@ obj-$(CONFIG_NET_SCH_SFQ) += sch_sfq.o
+ obj-$(CONFIG_NET_SCH_TBF) += sch_tbf.o
+ obj-$(CONFIG_NET_SCH_TEQL) += sch_teql.o
+ obj-$(CONFIG_NET_SCH_PRIO) += sch_prio.o
++obj-$(CONFIG_NET_SCH_MULTIQ) += sch_multiq.o
+ obj-$(CONFIG_NET_SCH_ATM) += sch_atm.o
+ obj-$(CONFIG_NET_SCH_NETEM) += sch_netem.o
+ obj-$(CONFIG_NET_CLS_U32) += cls_u32.o
+diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
+new file mode 100644
+index 0000000..ce00df4
+--- /dev/null
++++ b/net/sched/sch_multiq.c
+@@ -0,0 +1,469 @@
++/*
++ * Copyright (c) 2008, Intel Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms and conditions of the GNU General Public License,
++ * version 2, as published by the Free Software Foundation.
++ *
++ * This program is distributed in the hope it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
++ * Place - Suite 330, Boston, MA 02111-1307 USA.
++ *
++ * Author: Alexander Duyck <alexander.h.duyck@intel.com>
++ */
++
++#include <linux/module.h>
++#include <linux/types.h>
++#include <linux/kernel.h>
++#include <linux/string.h>
++#include <linux/errno.h>
++#include <linux/skbuff.h>
++#include <net/netlink.h>
++#include <net/pkt_sched.h>
++
++
++struct multiq_sched_data {
++ u16 bands;
++ u16 max_bands;
++ u16 curband;
++ struct tcf_proto *filter_list;
++ struct Qdisc **queues;
++};
++
++
++static struct Qdisc *
++multiq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ u32 band;
++ struct tcf_result res;
++ int err;
++
++ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
++ err = tc_classify(skb, q->filter_list, &res);
++#ifdef CONFIG_NET_CLS_ACT
++ switch (err) {
++ case TC_ACT_STOLEN:
++ case TC_ACT_QUEUED:
++ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
++ case TC_ACT_SHOT:
++ return NULL;
++ }
++#endif
++ band = skb_get_queue_mapping(skb);
++
++ if (band >= q->bands)
++ return q->queues[0];
++
++ return q->queues[band];
++}
++
++static int
++multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
++{
++ struct Qdisc *qdisc;
++ int ret;
++
++ qdisc = multiq_classify(skb, sch, &ret);
++#ifdef CONFIG_NET_CLS_ACT
++ if (qdisc == NULL) {
++
++ if (ret & __NET_XMIT_BYPASS)
++ sch->qstats.drops++;
++ kfree_skb(skb);
++ return ret;
++ }
++#endif
++
++ ret = qdisc_enqueue(skb, qdisc);
++ if (ret == NET_XMIT_SUCCESS) {
++ sch->bstats.bytes += qdisc_pkt_len(skb);
++ sch->bstats.packets++;
++ sch->q.qlen++;
++ return NET_XMIT_SUCCESS;
++ }
++ if (net_xmit_drop_count(ret))
++ sch->qstats.drops++;
++ return ret;
++}
++
++
++static int
++multiq_requeue(struct sk_buff *skb, struct Qdisc *sch)
++{
++ struct Qdisc *qdisc;
++ int ret;
++
++ qdisc = multiq_classify(skb, sch, &ret);
++#ifdef CONFIG_NET_CLS_ACT
++ if (qdisc == NULL) {
++ if (ret & __NET_XMIT_BYPASS)
++ sch->qstats.drops++;
++ kfree_skb(skb);
++ return ret;
++ }
++#endif
++
++ ret = qdisc->ops->requeue(skb, qdisc);
++ if (ret == NET_XMIT_SUCCESS) {
++ sch->q.qlen++;
++ sch->qstats.requeues++;
++ return NET_XMIT_SUCCESS;
++ }
++ if (net_xmit_drop_count(ret))
++ sch->qstats.drops++;
++ return ret;
++}
++
++
++static struct sk_buff *multiq_dequeue(struct Qdisc *sch)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ struct Qdisc *qdisc;
++ struct sk_buff *skb;
++ int band;
++
++ for (band = 0; band < q->bands; band++) {
++ /* cycle through bands to ensure fairness */
++ q->curband++;
++ if (q->curband >= q->bands)
++ q->curband = 0;
++
++ /* Check that target subqueue is available before
++ * pulling an skb to avoid excessive requeues
++ */
++ if (!__netif_subqueue_stopped(qdisc_dev(sch), q->curband)) {
++ qdisc = q->queues[q->curband];
++ skb = qdisc->dequeue(qdisc);
++ if (skb) {
++ sch->q.qlen--;
++ return skb;
++ }
++ }
++ }
++ return NULL;
++
++}
++
++static unsigned int multiq_drop(struct Qdisc *sch)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ int band;
++ unsigned int len;
++ struct Qdisc *qdisc;
++
++ for (band = q->bands-1; band >= 0; band--) {
++ qdisc = q->queues[band];
++ if (qdisc->ops->drop) {
++ len = qdisc->ops->drop(qdisc);
++ if (len != 0) {
++ sch->q.qlen--;
++ return len;
++ }
++ }
++ }
++ return 0;
++}
++
++
++static void
++multiq_reset(struct Qdisc *sch)
++{
++ u16 band;
++ struct multiq_sched_data *q = qdisc_priv(sch);
++
++ for (band = 0; band < q->bands; band++)
++ qdisc_reset(q->queues[band]);
++ sch->q.qlen = 0;
++ q->curband = 0;
++}
++
++static void
++multiq_destroy(struct Qdisc *sch)
++{
++ int band;
++ struct multiq_sched_data *q = qdisc_priv(sch);
++
++ tcf_destroy_chain(&q->filter_list);
++ for (band = 0; band < q->bands; band++)
++ qdisc_destroy(q->queues[band]);
++
++ kfree(q->queues);
++}
++
++static int multiq_tune(struct Qdisc *sch, struct nlattr *opt)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ struct tc_multiq_qopt *qopt;
++ int i;
++
++ if (sch->parent != TC_H_ROOT)
++ return -EINVAL;
++ if (!netif_is_multiqueue(qdisc_dev(sch)))
++ return -EINVAL;
++ if (nla_len(opt) < sizeof(*qopt))
++ return -EINVAL;
++
++ qopt = nla_data(opt);
++
++ qopt->bands = qdisc_dev(sch)->real_num_tx_queues;
++
++ sch_tree_lock(sch);
++ q->bands = qopt->bands;
++ for (i = q->bands; i < q->max_bands; i++) {
++ struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
++ if (child != &noop_qdisc) {
++ qdisc_tree_decrease_qlen(child, child->q.qlen);
++ qdisc_destroy(child);
++ }
++ }
++
++ sch_tree_unlock(sch);
++
++ for (i = 0; i < q->bands; i++) {
++ if (q->queues[i] == &noop_qdisc) {
++ struct Qdisc *child;
++ child = qdisc_create_dflt(qdisc_dev(sch),
++ sch->dev_queue,
++ &pfifo_qdisc_ops,
++ TC_H_MAKE(sch->handle,
++ i + 1));
++ if (child) {
++ sch_tree_lock(sch);
++ child = xchg(&q->queues[i], child);
++
++ if (child != &noop_qdisc) {
++ qdisc_tree_decrease_qlen(child,
++ child->q.qlen);
++ qdisc_destroy(child);
++ }
++ sch_tree_unlock(sch);
++ }
++ }
++ }
++ return 0;
++}
++
++static int multiq_init(struct Qdisc *sch, struct nlattr *opt)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ int i;
++
++ q->queues = NULL;
++
++ if (opt == NULL)
++ return -EINVAL;
++
++ q->max_bands = qdisc_dev(sch)->num_tx_queues;
++
++ q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL);
++ if (!q->queues)
++ return -ENOBUFS;
++ for (i = 0; i < q->max_bands; i++)
++ q->queues[i] = &noop_qdisc;
++
++ return multiq_tune(sch, opt);
++}
++
++static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ unsigned char *b = skb_tail_pointer(skb);
++ struct tc_multiq_qopt opt;
++
++ opt.bands = q->bands;
++ opt.max_bands = q->max_bands;
++
++ NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
++
++ return skb->len;
++
++nla_put_failure:
++ nlmsg_trim(skb, b);
++ return -1;
++}
++
++static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
++ struct Qdisc **old)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ unsigned long band = arg - 1;
++
++ if (band >= q->bands)
++ return -EINVAL;
++
++ if (new == NULL)
++ new = &noop_qdisc;
++
++ sch_tree_lock(sch);
++ *old = q->queues[band];
++ q->queues[band] = new;
++ qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
++ qdisc_reset(*old);
++ sch_tree_unlock(sch);
++
++ return 0;
++}
++
++static struct Qdisc *
++multiq_leaf(struct Qdisc *sch, unsigned long arg)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ unsigned long band = arg - 1;
++
++ if (band >= q->bands)
++ return NULL;
++
++ return q->queues[band];
++}
++
++static unsigned long multiq_get(struct Qdisc *sch, u32 classid)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ unsigned long band = TC_H_MIN(classid);
++
++ if (band - 1 >= q->bands)
++ return 0;
++ return band;
++}
++
++static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent,
++ u32 classid)
++{
++ return multiq_get(sch, classid);
++}
++
++
++static void multiq_put(struct Qdisc *q, unsigned long cl)
++{
++ return;
++}
++
++static int multiq_change(struct Qdisc *sch, u32 handle, u32 parent,
++ struct nlattr **tca, unsigned long *arg)
++{
++ unsigned long cl = *arg;
++ struct multiq_sched_data *q = qdisc_priv(sch);
++
++ if (cl - 1 > q->bands)
++ return -ENOENT;
++ return 0;
++}
++
++static int multiq_delete(struct Qdisc *sch, unsigned long cl)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ if (cl - 1 > q->bands)
++ return -ENOENT;
++ return 0;
++}
++
++
++static int multiq_dump_class(struct Qdisc *sch, unsigned long cl,
++ struct sk_buff *skb, struct tcmsg *tcm)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++
++ if (cl - 1 > q->bands)
++ return -ENOENT;
++ tcm->tcm_handle |= TC_H_MIN(cl);
++ if (q->queues[cl-1])
++ tcm->tcm_info = q->queues[cl-1]->handle;
++ return 0;
++}
++
++static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
++ struct gnet_dump *d)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ struct Qdisc *cl_q;
++
++ cl_q = q->queues[cl - 1];
++ if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 ||
++ gnet_stats_copy_queue(d, &cl_q->qstats) < 0)
++ return -1;
++
++ return 0;
++}
++
++static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++ int band;
++
++ if (arg->stop)
++ return;
++
++ for (band = 0; band < q->bands; band++) {
++ if (arg->count < arg->skip) {
++ arg->count++;
++ continue;
++ }
++ if (arg->fn(sch, band+1, arg) < 0) {
++ arg->stop = 1;
++ break;
++ }
++ arg->count++;
++ }
++}
++
++static struct tcf_proto **multiq_find_tcf(struct Qdisc *sch, unsigned long cl)
++{
++ struct multiq_sched_data *q = qdisc_priv(sch);
++
++ if (cl)
++ return NULL;
++ return &q->filter_list;
++}
++
++static const struct Qdisc_class_ops multiq_class_ops = {
++ .graft = multiq_graft,
++ .leaf = multiq_leaf,
++ .get = multiq_get,
++ .put = multiq_put,
++ .change = multiq_change,
++ .delete = multiq_delete,
++ .walk = multiq_walk,
++ .tcf_chain = multiq_find_tcf,
++ .bind_tcf = multiq_bind,
++ .unbind_tcf = multiq_put,
++ .dump = multiq_dump_class,
++ .dump_stats = multiq_dump_class_stats,
++};
++
++static struct Qdisc_ops multiq_qdisc_ops __read_mostly = {
++ .next = NULL,
++ .cl_ops = &multiq_class_ops,
++ .id = "multiq",
++ .priv_size = sizeof(struct multiq_sched_data),
++ .enqueue = multiq_enqueue,
++ .dequeue = multiq_dequeue,
++ .requeue = multiq_requeue,
++ .drop = multiq_drop,
++ .init = multiq_init,
++ .reset = multiq_reset,
++ .destroy = multiq_destroy,
++ .change = multiq_tune,
++ .dump = multiq_dump,
++ .owner = THIS_MODULE,
++};
++
++static int __init multiq_module_init(void)
++{
++ return register_qdisc(&multiq_qdisc_ops);
++}
++
++static void __exit multiq_module_exit(void)
++{
++ unregister_qdisc(&multiq_qdisc_ops);
++}
++
++module_init(multiq_module_init)
++module_exit(multiq_module_exit)
++
++MODULE_LICENSE("GPL");
+--
+1.5.2.4
+
projects / people / pmueller / ipfire-2.x.git / blobdiff