From 1e080f17750d1083e8a32f7b350584ae1cd7ff20 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 13 Sep 2021 15:53:30 -0700 Subject: [PATCH 1/3] net: sched: update default qdisc visibility after Tx queue cnt changes mq / mqprio make the default child qdiscs visible. They only do so for the qdiscs which are within real_num_tx_queues when the device is registered. Depending on order of calls in the driver, or if user space changes config via ethtool -L the number of qdiscs visible under tc qdisc show will differ from the number of queues. This is confusing to users and potentially to system configuration scripts which try to make sure qdiscs have the right parameters. Add a new Qdisc_ops callback and make relevant qdiscs TTRT. Note that this uncovers the "shortcut" created by commit 1f27cde313d7 ("net: sched: use pfifo_fast for non real queues") The default child qdiscs beyond initial real_num_tx are always pfifo_fast, no matter what the sysfs setting is. Fixing this gets a little tricky because we'd need to keep a reference on whatever the default qdisc was at the time of creation. In practice this is likely an non-issue the qdiscs likely have to be configured to non-default settings, so whatever user space is doing such configuration can replace the pfifos... now that it will see them. Reported-by: Matthew Massey Reviewed-by: Dave Taht Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- include/net/sch_generic.h | 4 ++++ net/core/dev.c | 2 ++ net/sched/sch_generic.c | 9 +++++++++ net/sched/sch_mq.c | 24 ++++++++++++++++++++++++ net/sched/sch_mqprio.c | 23 +++++++++++++++++++++++ 5 files changed, 62 insertions(+) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index c0069ac00e62d..8c2d611639fca 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -308,6 +308,8 @@ struct Qdisc_ops { struct netlink_ext_ack *extack); void (*attach)(struct Qdisc *sch); int (*change_tx_queue_len)(struct Qdisc *, unsigned int); + void (*change_real_num_tx)(struct Qdisc *sch, + unsigned int new_real_tx); int (*dump)(struct Qdisc *, struct sk_buff *); int (*dump_stats)(struct Qdisc *, struct gnet_dump *); @@ -684,6 +686,8 @@ void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *); void qdisc_class_hash_destroy(struct Qdisc_class_hash *); int dev_qdisc_change_tx_queue_len(struct net_device *dev); +void dev_qdisc_change_real_num_tx(struct net_device *dev, + unsigned int new_real_tx); void dev_init_scheduler(struct net_device *dev); void dev_shutdown(struct net_device *dev); void dev_activate(struct net_device *dev); diff --git a/net/core/dev.c b/net/core/dev.c index 74fd402d26dde..f930329f0dc26 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2921,6 +2921,8 @@ int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq) if (dev->num_tc) netif_setup_tc(dev, txq); + dev_qdisc_change_real_num_tx(dev, txq); + dev->real_num_tx_queues = txq; if (disabling) { diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index a8dd06c74e318..66d2fbe9ef501 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -1330,6 +1330,15 @@ static int qdisc_change_tx_queue_len(struct net_device *dev, return 0; } +void dev_qdisc_change_real_num_tx(struct net_device *dev, + unsigned int new_real_tx) +{ + struct Qdisc *qdisc = dev->qdisc; + + if (qdisc->ops->change_real_num_tx) + qdisc->ops->change_real_num_tx(qdisc, new_real_tx); +} + int dev_qdisc_change_tx_queue_len(struct net_device *dev) { bool up = dev->flags & IFF_UP; diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c index e79f1afe0cfd6..db18d8a860f9c 100644 --- a/net/sched/sch_mq.c +++ b/net/sched/sch_mq.c @@ -125,6 +125,29 @@ static void mq_attach(struct Qdisc *sch) priv->qdiscs = NULL; } +static void mq_change_real_num_tx(struct Qdisc *sch, unsigned int new_real_tx) +{ +#ifdef CONFIG_NET_SCHED + struct net_device *dev = qdisc_dev(sch); + struct Qdisc *qdisc; + unsigned int i; + + for (i = new_real_tx; i < dev->real_num_tx_queues; i++) { + qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping; + /* Only update the default qdiscs we created, + * qdiscs with handles are always hashed. + */ + if (qdisc != &noop_qdisc && !qdisc->handle) + qdisc_hash_del(qdisc); + } + for (i = dev->real_num_tx_queues; i < new_real_tx; i++) { + qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping; + if (qdisc != &noop_qdisc && !qdisc->handle) + qdisc_hash_add(qdisc, false); + } +#endif +} + static int mq_dump(struct Qdisc *sch, struct sk_buff *skb) { struct net_device *dev = qdisc_dev(sch); @@ -288,6 +311,7 @@ struct Qdisc_ops mq_qdisc_ops __read_mostly = { .init = mq_init, .destroy = mq_destroy, .attach = mq_attach, + .change_real_num_tx = mq_change_real_num_tx, .dump = mq_dump, .owner = THIS_MODULE, }; diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c index 8766ab5b87880..7f23a92849d5d 100644 --- a/net/sched/sch_mqprio.c +++ b/net/sched/sch_mqprio.c @@ -306,6 +306,28 @@ static void mqprio_attach(struct Qdisc *sch) priv->qdiscs = NULL; } +static void mqprio_change_real_num_tx(struct Qdisc *sch, + unsigned int new_real_tx) +{ + struct net_device *dev = qdisc_dev(sch); + struct Qdisc *qdisc; + unsigned int i; + + for (i = new_real_tx; i < dev->real_num_tx_queues; i++) { + qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping; + /* Only update the default qdiscs we created, + * qdiscs with handles are always hashed. + */ + if (qdisc != &noop_qdisc && !qdisc->handle) + qdisc_hash_del(qdisc); + } + for (i = dev->real_num_tx_queues; i < new_real_tx; i++) { + qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping; + if (qdisc != &noop_qdisc && !qdisc->handle) + qdisc_hash_add(qdisc, false); + } +} + static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch, unsigned long cl) { @@ -623,6 +645,7 @@ static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = { .init = mqprio_init, .destroy = mqprio_destroy, .attach = mqprio_attach, + .change_real_num_tx = mqprio_change_real_num_tx, .dump = mqprio_dump, .owner = THIS_MODULE, }; From 2e367522ce6bc302f2613a0334c9930dafccf2e7 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 13 Sep 2021 15:53:31 -0700 Subject: [PATCH 2/3] netdevsim: add ability to change channel count For testing visibility of mq/mqprio default children. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- drivers/net/netdevsim/ethtool.c | 28 ++++++++++++++++++++++++++++ drivers/net/netdevsim/netdevsim.h | 1 + 2 files changed, 29 insertions(+) diff --git a/drivers/net/netdevsim/ethtool.c b/drivers/net/netdevsim/ethtool.c index b03a0513eb7e7..0ab6a40be6114 100644 --- a/drivers/net/netdevsim/ethtool.c +++ b/drivers/net/netdevsim/ethtool.c @@ -81,6 +81,30 @@ static int nsim_set_ringparam(struct net_device *dev, return 0; } +static void +nsim_get_channels(struct net_device *dev, struct ethtool_channels *ch) +{ + struct netdevsim *ns = netdev_priv(dev); + + ch->max_combined = ns->nsim_bus_dev->num_queues; + ch->combined_count = ns->ethtool.channels; +} + +static int +nsim_set_channels(struct net_device *dev, struct ethtool_channels *ch) +{ + struct netdevsim *ns = netdev_priv(dev); + int err; + + err = netif_set_real_num_queues(dev, ch->combined_count, + ch->combined_count); + if (err) + return err; + + ns->ethtool.channels = ch->combined_count; + return 0; +} + static int nsim_get_fecparam(struct net_device *dev, struct ethtool_fecparam *fecparam) { @@ -118,6 +142,8 @@ static const struct ethtool_ops nsim_ethtool_ops = { .get_coalesce = nsim_get_coalesce, .get_ringparam = nsim_get_ringparam, .set_ringparam = nsim_set_ringparam, + .get_channels = nsim_get_channels, + .set_channels = nsim_set_channels, .get_fecparam = nsim_get_fecparam, .set_fecparam = nsim_set_fecparam, }; @@ -141,6 +167,8 @@ void nsim_ethtool_init(struct netdevsim *ns) ns->ethtool.fec.fec = ETHTOOL_FEC_NONE; ns->ethtool.fec.active_fec = ETHTOOL_FEC_NONE; + ns->ethtool.channels = ns->nsim_bus_dev->num_queues; + ethtool = debugfs_create_dir("ethtool", ns->nsim_dev_port->ddir); debugfs_create_u32("get_err", 0600, ethtool, &ns->ethtool.get_err); diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h index 793c86dc5a9c1..d42eec05490f4 100644 --- a/drivers/net/netdevsim/netdevsim.h +++ b/drivers/net/netdevsim/netdevsim.h @@ -62,6 +62,7 @@ struct nsim_ethtool_pauseparam { struct nsim_ethtool { u32 get_err; u32 set_err; + u32 channels; struct nsim_ethtool_pauseparam pauseparam; struct ethtool_coalesce coalesce; struct ethtool_ringparam ring; From 2d6a58996ee23f85745a8e42edaad7a2b86d1a83 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 13 Sep 2021 15:53:32 -0700 Subject: [PATCH 3/3] selftests: net: test ethtool -L vs mq Add a selftest for checking mq children are visible after ethtool -L. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- .../drivers/net/netdevsim/ethtool-common.sh | 2 +- .../drivers/net/netdevsim/tc-mq-visibility.sh | 77 +++++++++++++++++++ 2 files changed, 78 insertions(+), 1 deletion(-) create mode 100755 tools/testing/selftests/drivers/net/netdevsim/tc-mq-visibility.sh diff --git a/tools/testing/selftests/drivers/net/netdevsim/ethtool-common.sh b/tools/testing/selftests/drivers/net/netdevsim/ethtool-common.sh index 7ca1f030d2099..922744059aaa2 100644 --- a/tools/testing/selftests/drivers/net/netdevsim/ethtool-common.sh +++ b/tools/testing/selftests/drivers/net/netdevsim/ethtool-common.sh @@ -50,7 +50,7 @@ function make_netdev { modprobe netdevsim fi - echo $NSIM_ID > /sys/bus/netdevsim/new_device + echo $NSIM_ID $@ > /sys/bus/netdevsim/new_device # get new device name ls /sys/bus/netdevsim/devices/netdevsim${NSIM_ID}/net/ } diff --git a/tools/testing/selftests/drivers/net/netdevsim/tc-mq-visibility.sh b/tools/testing/selftests/drivers/net/netdevsim/tc-mq-visibility.sh new file mode 100755 index 0000000000000..fd13c8cfb7a87 --- /dev/null +++ b/tools/testing/selftests/drivers/net/netdevsim/tc-mq-visibility.sh @@ -0,0 +1,77 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0-only + +source ethtool-common.sh + +set -o pipefail + +n_children() { + n=$(tc qdisc show dev $NDEV | grep '^qdisc' | wc -l) + echo $((n - 1)) +} + +tcq() { + tc qdisc $1 dev $NDEV ${@:2} +} + +n_child_assert() { + n=$(n_children) + if [ $n -ne $1 ]; then + echo "ERROR ($root): ${@:2}, expected $1 have $n" + ((num_errors++)) + else + ((num_passes++)) + fi +} + + +for root in mq mqprio; do + NDEV=$(make_netdev 1 4) + + opts= + [ $root == "mqprio" ] && opts='hw 0 num_tc 1 map 0 0 0 0 queues 1@0' + + tcq add root handle 100: $root $opts + n_child_assert 4 'Init' + + # All defaults + + for n in 3 2 1 2 3 4 1 4; do + ethtool -L $NDEV combined $n + n_child_assert $n "Change queues to $n while down" + done + + ip link set dev $NDEV up + + for n in 3 2 1 2 3 4 1 4; do + ethtool -L $NDEV combined $n + n_child_assert $n "Change queues to $n while up" + done + + # One real one + tcq replace parent 100:4 handle 204: pfifo_fast + n_child_assert 4 "One real queue" + + ethtool -L $NDEV combined 1 + n_child_assert 2 "One real queue, one default" + + ethtool -L $NDEV combined 4 + n_child_assert 4 "One real queue, rest default" + + # Graft some + tcq replace parent 100:1 handle 204: + n_child_assert 3 "Grafted" + + ethtool -L $NDEV combined 1 + n_child_assert 1 "Grafted, one" + + cleanup_nsim +done + +if [ $num_errors -eq 0 ]; then + echo "PASSED all $((num_passes)) checks" + exit 0 +else + echo "FAILED $num_errors/$((num_errors+num_passes)) checks" + exit 1 +fi