From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Patrick McHardy <kaber@trash.net>,
Vladislav Yasevich <vyasevic@redhat.com>
Subject: Re: [PATCH net-next] macvtap/macvlan: use IFF_NO_QUEUE
Date: Tue, 25 Aug 2015 13:17:30 +0300 [thread overview]
Message-ID: <20150825131608-mutt-send-email-mst@redhat.com> (raw)
In-Reply-To: <1440405192-25926-1-git-send-email-jasowang@redhat.com>
On Mon, Aug 24, 2015 at 04:33:12PM +0800, Jason Wang wrote:
> For macvlan, switch to use IFF_NO_QUEUE instead of tx_queue_len = 0.
>
> For macvtap, after commit 6acf54f1cf0a6747bac9fea26f34cfc5a9029523
> ("macvtap: Add support of packet capture on macvtap
> device."). Multiqueue macvtap suffers from single qdisc lock
> contention. This is because macvtap claims a non zero tx_queue_len and
> it reuses this value as it socket receive queue size.Thanks to
> IFF_NO_QUEUE, we can remove the lock contention without breaking
> existing socket receive queue length logic.
>
> Cc: Patrick McHardy <kaber@trash.net>
> Cc: Vladislav Yasevich <vyasevic@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
Seems to make sense. Give me a day or two to get over the jet lag
(and get out from under the pile of mail accumulated while I was traveling),
I'll review properly and ack.
> ---
> drivers/net/macvlan.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
> index 47da435..09d8718 100644
> --- a/drivers/net/macvlan.c
> +++ b/drivers/net/macvlan.c
> @@ -1056,7 +1056,7 @@ void macvlan_common_setup(struct net_device *dev)
>
> dev->priv_flags &= ~IFF_TX_SKB_SHARING;
> netif_keep_dst(dev);
> - dev->priv_flags |= IFF_UNICAST_FLT;
> + dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
> dev->netdev_ops = &macvlan_netdev_ops;
> dev->destructor = free_netdev;
> dev->header_ops = &macvlan_hard_header_ops;
> @@ -1067,7 +1067,6 @@ EXPORT_SYMBOL_GPL(macvlan_common_setup);
> static void macvlan_setup(struct net_device *dev)
> {
> macvlan_common_setup(dev);
> - dev->tx_queue_len = 0;
> }
>
> static int macvlan_port_create(struct net_device *dev)
> --
> 2.1.4
next prev parent reply other threads:[~2015-08-25 10:17 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-24 8:33 [PATCH net-next] macvtap/macvlan: use IFF_NO_QUEUE Jason Wang
2015-08-25 10:17 ` Michael S. Tsirkin [this message]
2015-08-25 11:30 ` Jason Wang
2015-08-25 16:32 ` Vlad Yasevich
2015-08-26 5:45 ` Jason Wang
2015-08-27 10:43 ` Michael S. Tsirkin
2015-08-28 2:42 ` Jason Wang
2015-08-28 12:25 ` Vlad Yasevich
2015-08-31 2:45 ` Jason Wang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150825131608-mutt-send-email-mst@redhat.com \
--to=mst@redhat.com \
--cc=jasowang@redhat.com \
--cc=kaber@trash.net \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=vyasevic@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).