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* [PATCH net-next] net: sched: calls synchronize_net() only when needed
@ 2025-01-09 17:18 Eric Dumazet
  2025-01-10  5:33 ` Cong Wang
  2025-01-14  9:50 ` patchwork-bot+netdevbpf
  0 siblings, 2 replies; 6+ messages in thread
From: Eric Dumazet @ 2025-01-09 17:18 UTC (permalink / raw)
  To: David S . Miller, Jakub Kicinski, Paolo Abeni
  Cc: Simon Horman, Jamal Hadi Salim, Cong Wang, Jiri Pirko, netdev,
	eric.dumazet, Eric Dumazet

dev_deactivate_many() role is to remove the qdiscs
of a network device.

When/if a qdisc is dismantled, an rcu grace period
is needed to make sure all outstanding qdisc enqueue
are done before we proceed with a qdisc reset.

Most virtual devices do not have a qdisc (if we exclude
noqueue ones).

We can call the expensive synchronize_net() only
if needed.

Note that dev_deactivate_many() does not have to deal
with qdisc-less dev_queue_xmit, as an old comment
was claiming.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/sched/sch_generic.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index bb7dd351bd651d4aa16945816ee26df3c4a48645..14ab2f4c190a1e201dd1788b413a06e799a829f2 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -1277,15 +1277,17 @@ static void qdisc_deactivate(struct Qdisc *qdisc)
 
 static void dev_deactivate_queue(struct net_device *dev,
 				 struct netdev_queue *dev_queue,
-				 void *_qdisc_default)
+				 void *_sync_needed)
 {
-	struct Qdisc *qdisc_default = _qdisc_default;
+	bool *sync_needed = _sync_needed;
 	struct Qdisc *qdisc;
 
 	qdisc = rtnl_dereference(dev_queue->qdisc);
 	if (qdisc) {
+		if (qdisc->enqueue)
+			*sync_needed = true;
 		qdisc_deactivate(qdisc);
-		rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
+		rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
 	}
 }
 
@@ -1352,24 +1354,22 @@ static bool some_qdisc_is_busy(struct net_device *dev)
  */
 void dev_deactivate_many(struct list_head *head)
 {
+	bool sync_needed = false;
 	struct net_device *dev;
 
 	list_for_each_entry(dev, head, close_list) {
 		netdev_for_each_tx_queue(dev, dev_deactivate_queue,
-					 &noop_qdisc);
+					 &sync_needed);
 		if (dev_ingress_queue(dev))
 			dev_deactivate_queue(dev, dev_ingress_queue(dev),
-					     &noop_qdisc);
+					     &sync_needed);
 
 		netdev_watchdog_down(dev);
 	}
 
-	/* Wait for outstanding qdisc-less dev_queue_xmit calls or
-	 * outstanding qdisc enqueuing calls.
-	 * This is avoided if all devices are in dismantle phase :
-	 * Caller will call synchronize_net() for us
-	 */
-	synchronize_net();
+	/* Wait for outstanding qdisc enqueuing calls. */
+	if (sync_needed)
+		synchronize_net();
 
 	list_for_each_entry(dev, head, close_list) {
 		netdev_for_each_tx_queue(dev, dev_reset_queue, NULL);
-- 
2.47.1.613.gc27f4b7a9f-goog


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH net-next] net: sched: calls synchronize_net() only when needed
  2025-01-09 17:18 [PATCH net-next] net: sched: calls synchronize_net() only when needed Eric Dumazet
@ 2025-01-10  5:33 ` Cong Wang
  2025-01-10  5:49   ` Eric Dumazet
  2025-01-14  9:50 ` patchwork-bot+netdevbpf
  1 sibling, 1 reply; 6+ messages in thread
From: Cong Wang @ 2025-01-10  5:33 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: David S . Miller, Jakub Kicinski, Paolo Abeni, Simon Horman,
	Jamal Hadi Salim, Jiri Pirko, netdev, eric.dumazet

On Thu, Jan 09, 2025 at 05:18:50PM +0000, Eric Dumazet wrote:
> dev_deactivate_many() role is to remove the qdiscs
> of a network device.
> 
> When/if a qdisc is dismantled, an rcu grace period
> is needed to make sure all outstanding qdisc enqueue
> are done before we proceed with a qdisc reset.
> 
> Most virtual devices do not have a qdisc (if we exclude
> noqueue ones).

Such as? To me, most virtual devices use noqueue:

$ git grep IFF_NO_QUEUE -- drivers/net/
drivers/net/amt.c:      dev->priv_flags         |= IFF_NO_QUEUE;
drivers/net/bareudp.c:  dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/bonding/bond_main.c:        bond_dev->priv_flags |= IFF_BONDING | IFF_UNICAST_FLT | IFF_NO_QUEUE;
drivers/net/caif/caif_serial.c: dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/dummy.c:    dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:        dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/ethernet/netronome/nfp/nfp_net_repr.c:      netdev->priv_flags |= IFF_NO_QUEUE | IFF_DISABLE_NETPOLL;
drivers/net/geneve.c:   dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
drivers/net/gtp.c:      dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/ipvlan/ipvlan_main.c:       dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
drivers/net/ipvlan/ipvtap.c:    dev->priv_flags &= ~IFF_NO_QUEUE;
drivers/net/loopback.c: dev->priv_flags         |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
drivers/net/macsec.c:   dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/macvlan.c:  dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/net_failover.c:     failover_dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
drivers/net/netdevsim/netdev.c:                    IFF_NO_QUEUE;
drivers/net/netkit.c:   dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/nlmon.c:    dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/pfcp.c:     dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/team/team_core.c:   dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/veth.c:     dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/vrf.c:      dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/vsockmon.c: dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/vxlan/vxlan_core.c: dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/wan/hdlc_fr.c:      dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/wireguard/device.c: dev->priv_flags |= IFF_NO_QUEUE;
drivers/net/wireless/virtual/mac80211_hwsim.c:  dev->priv_flags |= IFF_NO_QUEUE;


And noqueue_qdisc_ops sets ->enqueue to noop_enqueue():

struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
        .id             =       "noqueue",
        .priv_size      =       0,
        .init           =       noqueue_init,
        .enqueue        =       noop_enqueue,
        .dequeue        =       noop_dequeue,
        .peek           =       noop_dequeue,
        .owner          =       THIS_MODULE,
};

Thanks.

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH net-next] net: sched: calls synchronize_net() only when needed
  2025-01-10  5:33 ` Cong Wang
@ 2025-01-10  5:49   ` Eric Dumazet
  2025-01-13 16:08     ` Eric Dumazet
  0 siblings, 1 reply; 6+ messages in thread
From: Eric Dumazet @ 2025-01-10  5:49 UTC (permalink / raw)
  To: Cong Wang
  Cc: David S . Miller, Jakub Kicinski, Paolo Abeni, Simon Horman,
	Jamal Hadi Salim, Jiri Pirko, netdev, eric.dumazet

On Fri, Jan 10, 2025 at 6:33 AM Cong Wang <xiyou.wangcong@gmail.com> wrote:
>
> On Thu, Jan 09, 2025 at 05:18:50PM +0000, Eric Dumazet wrote:
> > dev_deactivate_many() role is to remove the qdiscs
> > of a network device.
> >
> > When/if a qdisc is dismantled, an rcu grace period
> > is needed to make sure all outstanding qdisc enqueue
> > are done before we proceed with a qdisc reset.
> >
> > Most virtual devices do not have a qdisc (if we exclude
> > noqueue ones).
>
> Such as? To me, most virtual devices use noqueue:
>
> $ git grep IFF_NO_QUEUE -- drivers/net/
> drivers/net/amt.c:      dev->priv_flags         |= IFF_NO_QUEUE;
> drivers/net/bareudp.c:  dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/bonding/bond_main.c:        bond_dev->priv_flags |= IFF_BONDING | IFF_UNICAST_FLT | IFF_NO_QUEUE;
> drivers/net/caif/caif_serial.c: dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/dummy.c:    dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
> drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:        dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/ethernet/netronome/nfp/nfp_net_repr.c:      netdev->priv_flags |= IFF_NO_QUEUE | IFF_DISABLE_NETPOLL;
> drivers/net/geneve.c:   dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
> drivers/net/gtp.c:      dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/ipvlan/ipvlan_main.c:       dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
> drivers/net/ipvlan/ipvtap.c:    dev->priv_flags &= ~IFF_NO_QUEUE;
> drivers/net/loopback.c: dev->priv_flags         |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
> drivers/net/macsec.c:   dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/macvlan.c:  dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/net_failover.c:     failover_dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
> drivers/net/netdevsim/netdev.c:                    IFF_NO_QUEUE;
> drivers/net/netkit.c:   dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/nlmon.c:    dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/pfcp.c:     dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/team/team_core.c:   dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/veth.c:     dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/vrf.c:      dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/vsockmon.c: dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/vxlan/vxlan_core.c: dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/wan/hdlc_fr.c:      dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/wireguard/device.c: dev->priv_flags |= IFF_NO_QUEUE;
> drivers/net/wireless/virtual/mac80211_hwsim.c:  dev->priv_flags |= IFF_NO_QUEUE;
>
>
> And noqueue_qdisc_ops sets ->enqueue to noop_enqueue():
>
> struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
>         .id             =       "noqueue",
>         .priv_size      =       0,
>         .init           =       noqueue_init,
>         .enqueue        =       noop_enqueue,
>         .dequeue        =       noop_dequeue,
>         .peek           =       noop_dequeue,
>         .owner          =       THIS_MODULE,
> };

Sure, but please a look at :

static int noqueue_init(struct Qdisc *qdisc, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
        /* register_qdisc() assigns a default of noop_enqueue if unset,
        * but __dev_queue_xmit() treats noqueue only as such
        * if this is NULL - so clear it here. */
        qdisc->enqueue = NULL;
        return 0;
}

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH net-next] net: sched: calls synchronize_net() only when needed
  2025-01-10  5:49   ` Eric Dumazet
@ 2025-01-13 16:08     ` Eric Dumazet
  2025-01-14  9:17       ` Paolo Abeni
  0 siblings, 1 reply; 6+ messages in thread
From: Eric Dumazet @ 2025-01-13 16:08 UTC (permalink / raw)
  To: Cong Wang
  Cc: David S . Miller, Jakub Kicinski, Paolo Abeni, Simon Horman,
	Jamal Hadi Salim, Jiri Pirko, netdev, eric.dumazet

On Fri, Jan 10, 2025 at 6:49 AM Eric Dumazet <edumazet@google.com> wrote:
>
> On Fri, Jan 10, 2025 at 6:33 AM Cong Wang <xiyou.wangcong@gmail.com> wrote:
> >
> > On Thu, Jan 09, 2025 at 05:18:50PM +0000, Eric Dumazet wrote:
> > > dev_deactivate_many() role is to remove the qdiscs
> > > of a network device.
> > >
> > > When/if a qdisc is dismantled, an rcu grace period
> > > is needed to make sure all outstanding qdisc enqueue
> > > are done before we proceed with a qdisc reset.
> > >
> > > Most virtual devices do not have a qdisc (if we exclude
> > > noqueue ones).
> >
> > Such as? To me, most virtual devices use noqueue:
> >
> > $ git grep IFF_NO_QUEUE -- drivers/net/
> > drivers/net/amt.c:      dev->priv_flags         |= IFF_NO_QUEUE;
> > drivers/net/bareudp.c:  dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/bonding/bond_main.c:        bond_dev->priv_flags |= IFF_BONDING | IFF_UNICAST_FLT | IFF_NO_QUEUE;
> > drivers/net/caif/caif_serial.c: dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/dummy.c:    dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
> > drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:        dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/ethernet/netronome/nfp/nfp_net_repr.c:      netdev->priv_flags |= IFF_NO_QUEUE | IFF_DISABLE_NETPOLL;
> > drivers/net/geneve.c:   dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
> > drivers/net/gtp.c:      dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/ipvlan/ipvlan_main.c:       dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
> > drivers/net/ipvlan/ipvtap.c:    dev->priv_flags &= ~IFF_NO_QUEUE;
> > drivers/net/loopback.c: dev->priv_flags         |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
> > drivers/net/macsec.c:   dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/macvlan.c:  dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/net_failover.c:     failover_dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
> > drivers/net/netdevsim/netdev.c:                    IFF_NO_QUEUE;
> > drivers/net/netkit.c:   dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/nlmon.c:    dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/pfcp.c:     dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/team/team_core.c:   dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/veth.c:     dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/vrf.c:      dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/vsockmon.c: dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/vxlan/vxlan_core.c: dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/wan/hdlc_fr.c:      dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/wireguard/device.c: dev->priv_flags |= IFF_NO_QUEUE;
> > drivers/net/wireless/virtual/mac80211_hwsim.c:  dev->priv_flags |= IFF_NO_QUEUE;
> >
> >
> > And noqueue_qdisc_ops sets ->enqueue to noop_enqueue():
> >
> > struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
> >         .id             =       "noqueue",
> >         .priv_size      =       0,
> >         .init           =       noqueue_init,
> >         .enqueue        =       noop_enqueue,
> >         .dequeue        =       noop_dequeue,
> >         .peek           =       noop_dequeue,
> >         .owner          =       THIS_MODULE,
> > };
>
> Sure, but please a look at :
>
> static int noqueue_init(struct Qdisc *qdisc, struct nlattr *opt,
> struct netlink_ext_ack *extack)
> {
>         /* register_qdisc() assigns a default of noop_enqueue if unset,
>         * but __dev_queue_xmit() treats noqueue only as such
>         * if this is NULL - so clear it here. */
>         qdisc->enqueue = NULL;
>         return 0;
> }

How can we proceed on this patch ?

I can remove the "(if we exclude noqueue ones)" part if this is confusing.

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH net-next] net: sched: calls synchronize_net() only when needed
  2025-01-13 16:08     ` Eric Dumazet
@ 2025-01-14  9:17       ` Paolo Abeni
  0 siblings, 0 replies; 6+ messages in thread
From: Paolo Abeni @ 2025-01-14  9:17 UTC (permalink / raw)
  To: Eric Dumazet, Cong Wang
  Cc: David S . Miller, Jakub Kicinski, Simon Horman, Jamal Hadi Salim,
	Jiri Pirko, netdev, eric.dumazet

On 1/13/25 5:08 PM, Eric Dumazet wrote:
> On Fri, Jan 10, 2025 at 6:49 AM Eric Dumazet <edumazet@google.com> wrote:
>>
>> On Fri, Jan 10, 2025 at 6:33 AM Cong Wang <xiyou.wangcong@gmail.com> wrote:
>>>
>>> On Thu, Jan 09, 2025 at 05:18:50PM +0000, Eric Dumazet wrote:
>>>> dev_deactivate_many() role is to remove the qdiscs
>>>> of a network device.
>>>>
>>>> When/if a qdisc is dismantled, an rcu grace period
>>>> is needed to make sure all outstanding qdisc enqueue
>>>> are done before we proceed with a qdisc reset.
>>>>
>>>> Most virtual devices do not have a qdisc (if we exclude
>>>> noqueue ones).
>>>
>>> Such as? To me, most virtual devices use noqueue:
>>>
>>> $ git grep IFF_NO_QUEUE -- drivers/net/
>>> drivers/net/amt.c:      dev->priv_flags         |= IFF_NO_QUEUE;
>>> drivers/net/bareudp.c:  dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/bonding/bond_main.c:        bond_dev->priv_flags |= IFF_BONDING | IFF_UNICAST_FLT | IFF_NO_QUEUE;
>>> drivers/net/caif/caif_serial.c: dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/dummy.c:    dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
>>> drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:        dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/ethernet/netronome/nfp/nfp_net_repr.c:      netdev->priv_flags |= IFF_NO_QUEUE | IFF_DISABLE_NETPOLL;
>>> drivers/net/geneve.c:   dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
>>> drivers/net/gtp.c:      dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/ipvlan/ipvlan_main.c:       dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
>>> drivers/net/ipvlan/ipvtap.c:    dev->priv_flags &= ~IFF_NO_QUEUE;
>>> drivers/net/loopback.c: dev->priv_flags         |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
>>> drivers/net/macsec.c:   dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/macvlan.c:  dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/net_failover.c:     failover_dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
>>> drivers/net/netdevsim/netdev.c:                    IFF_NO_QUEUE;
>>> drivers/net/netkit.c:   dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/nlmon.c:    dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/pfcp.c:     dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/team/team_core.c:   dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/veth.c:     dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/vrf.c:      dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/vsockmon.c: dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/vxlan/vxlan_core.c: dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/wan/hdlc_fr.c:      dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/wireguard/device.c: dev->priv_flags |= IFF_NO_QUEUE;
>>> drivers/net/wireless/virtual/mac80211_hwsim.c:  dev->priv_flags |= IFF_NO_QUEUE;
>>>
>>>
>>> And noqueue_qdisc_ops sets ->enqueue to noop_enqueue():
>>>
>>> struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
>>>         .id             =       "noqueue",
>>>         .priv_size      =       0,
>>>         .init           =       noqueue_init,
>>>         .enqueue        =       noop_enqueue,
>>>         .dequeue        =       noop_dequeue,
>>>         .peek           =       noop_dequeue,
>>>         .owner          =       THIS_MODULE,
>>> };
>>
>> Sure, but please a look at :
>>
>> static int noqueue_init(struct Qdisc *qdisc, struct nlattr *opt,
>> struct netlink_ext_ack *extack)
>> {
>>         /* register_qdisc() assigns a default of noop_enqueue if unset,
>>         * but __dev_queue_xmit() treats noqueue only as such
>>         * if this is NULL - so clear it here. */
>>         qdisc->enqueue = NULL;
>>         return 0;
>> }
> 
> How can we proceed on this patch ?
> 
> I can remove the "(if we exclude noqueue ones)" part if this is confusing.

I personally interpret the lack of reply from Cong to your previous
message as agreement/understanding. I'll drop the blamed sentence from
the commit message when applying the patch.

BTW, in the long run I think it would be nice to remove the noqueue_init
hack - AFAICS no in-tree kernel has NULL enqueue/dequeue/peek CB, so the
related checks in register_qdisc() could possibly be dropped.

/P


^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH net-next] net: sched: calls synchronize_net() only when needed
  2025-01-09 17:18 [PATCH net-next] net: sched: calls synchronize_net() only when needed Eric Dumazet
  2025-01-10  5:33 ` Cong Wang
@ 2025-01-14  9:50 ` patchwork-bot+netdevbpf
  1 sibling, 0 replies; 6+ messages in thread
From: patchwork-bot+netdevbpf @ 2025-01-14  9:50 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: davem, kuba, pabeni, horms, jhs, xiyou.wangcong, jiri, netdev,
	eric.dumazet

Hello:

This patch was applied to netdev/net-next.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Thu,  9 Jan 2025 17:18:50 +0000 you wrote:
> dev_deactivate_many() role is to remove the qdiscs
> of a network device.
> 
> When/if a qdisc is dismantled, an rcu grace period
> is needed to make sure all outstanding qdisc enqueue
> are done before we proceed with a qdisc reset.
> 
> [...]

Here is the summary with links:
  - [net-next] net: sched: calls synchronize_net() only when needed
    https://git.kernel.org/netdev/net-next/c/88df16f851ad

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html



^ permalink raw reply	[flat|nested] 6+ messages in thread
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2025-01-09 17:18 [PATCH net-next] net: sched: calls synchronize_net() only when needed Eric Dumazet
2025-01-10  5:33 ` Cong Wang
2025-01-10  5:49   ` Eric Dumazet
2025-01-13 16:08     ` Eric Dumazet
2025-01-14  9:17       ` Paolo Abeni
2025-01-14  9:50 ` patchwork-bot+netdevbpf

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