From: Ido Schimmel <idosch@idosch.org>
To: Neil Horman <nhorman@tuxdriver.com>
Cc: netdev@vger.kernel.org, davem@davemloft.net, dsahern@gmail.com,
roopa@cumulusnetworks.com, nikolay@cumulusnetworks.com,
jakub.kicinski@netronome.com, toke@redhat.com,
andy@greyhouse.net, f.fainelli@gmail.com, andrew@lunn.ch,
vivien.didelot@gmail.com, mlxsw@mellanox.com,
Ido Schimmel <idosch@mellanox.com>
Subject: Re: [RFC PATCH net-next 10/12] drop_monitor: Add packet alert mode
Date: Tue, 23 Jul 2019 17:16:25 +0300 [thread overview]
Message-ID: <20190723141625.GA8972@splinter> (raw)
In-Reply-To: <20190723124340.GA10377@hmswarspite.think-freely.org>
On Tue, Jul 23, 2019 at 08:43:40AM -0400, Neil Horman wrote:
> On Mon, Jul 22, 2019 at 09:31:32PM +0300, Ido Schimmel wrote:
> > +static void net_dm_packet_work(struct work_struct *work)
> > +{
> > + struct per_cpu_dm_data *data;
> > + struct sk_buff_head list;
> > + struct sk_buff *skb;
> > + unsigned long flags;
> > +
> > + data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
> > +
> > + __skb_queue_head_init(&list);
> > +
> > + spin_lock_irqsave(&data->drop_queue.lock, flags);
> > + skb_queue_splice_tail_init(&data->drop_queue, &list);
> > + spin_unlock_irqrestore(&data->drop_queue.lock, flags);
> > +
> These functions are all executed in a per-cpu context. While theres nothing
> wrong with using a spinlock here, I think you can get away with just doing
> local_irqsave and local_irq_restore.
Hi Neil,
Thanks a lot for reviewing. I might be missing something, but please
note that this function is executed from a workqueue and therefore the
CPU it is running on does not have to be the same CPU to which 'data'
belongs to. If so, I'm not sure how I can avoid taking the spinlock, as
otherwise two different CPUs can modify the list concurrently.
>
> Neil
>
> > + while ((skb = __skb_dequeue(&list)))
> > + net_dm_packet_report(skb);
> > +}
next prev parent reply other threads:[~2019-07-23 14:16 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-22 18:31 [RFC PATCH net-next 00/12] drop_monitor: Capture dropped packets and metadata Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 01/12] drop_monitor: Use correct error code Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 02/12] drop_monitor: Rename and document scope of mutex Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 03/12] drop_monitor: Document scope of spinlock Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 04/12] drop_monitor: Avoid multiple blank lines Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 05/12] drop_monitor: Add extack support Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 06/12] drop_monitor: Use pre_doit / post_doit hooks Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 07/12] drop_monitor: Split tracing enable / disable to different functions Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 08/12] drop_monitor: Initialize timer and work item upon tracing enable Ido Schimmel
2019-07-24 9:01 ` Jiri Pirko
2019-07-24 17:02 ` Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 09/12] drop_monitor: Require CAP_NET_ADMIN for drop monitor configuration Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 10/12] drop_monitor: Add packet alert mode Ido Schimmel
2019-07-23 12:43 ` Neil Horman
2019-07-23 14:16 ` Ido Schimmel [this message]
2019-07-23 15:14 ` Neil Horman
2019-07-24 7:10 ` Ido Schimmel
2019-07-24 12:53 ` Jiri Pirko
2019-07-24 16:57 ` Ido Schimmel
2019-07-29 9:52 ` [drop_monitor] 98ffbd6cd2: will-it-scale.per_thread_ops -17.5% regression kernel test robot
2019-08-05 11:56 ` Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 11/12] drop_monitor: Allow truncation of dropped packets Ido Schimmel
[not found] ` <20190724125537.GC2225@nanopsycho>
2019-07-24 16:49 ` Ido Schimmel
2019-07-22 18:31 ` [RFC PATCH net-next 12/12] drop_monitor: Add a command to query current configuration Ido Schimmel
2019-07-22 19:43 ` [RFC PATCH net-next 00/12] drop_monitor: Capture dropped packets and metadata Toke Høiland-Jørgensen
2019-07-23 6:46 ` Ido Schimmel
2019-07-23 12:17 ` Toke Høiland-Jørgensen
2019-07-23 15:14 ` Ido Schimmel
2019-07-23 15:47 ` David Ahern
2019-07-24 7:57 ` Ido Schimmel
2019-07-23 16:08 ` Toke Høiland-Jørgensen
2019-07-24 8:10 ` Ido Schimmel
2019-07-24 9:51 ` Toke Høiland-Jørgensen
2019-07-24 12:58 ` Jiri Pirko
2019-07-24 16:48 ` Ido Schimmel
2019-07-24 22:48 ` David Miller
2019-07-24 15:15 ` Jiri Pirko
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