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Date: Mon, 5 Aug 2013 22:16:20 +0200
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Subject: Re: [net] protecting interfaces from races between control and data ?
From: Luigi Rizzo <rizzo@iet.unipi.it>
To: Adrian Chadd <adrian@freebsd.org>
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Cc: FreeBSD current mailing list <current@freebsd.org>,
 Bryan Venteicher <bryanv@daemoninthecloset.org>,
 Navdeep Parhar <np@freebsd.org>, net@freebsd.org,
 Giuseppe Lettieri <g.lettieri@iet.unipi.it>, Jack Vogel <jfvogel@gmail.com>
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On Mon, Aug 5, 2013 at 8:19 PM, Adrian Chadd <adrian@freebsd.org> wrote:

> No, brian said two things:
>
> * the flag, protected by the core lock
> * per-queue flags
>

i see no mentions on per-queue flags on his email.
This is the relevant part

------------

What I've done in my drivers is:
  * Lock the core mutex
  * Clear IFF_DRV_RUNNING
  * Lock/unlock each queue's lock

The various Rx/Tx queue functions check for IFF_DRV_RUNNING after
(re)acquiring their queue lock. See at vtnet_stop_rendezvous() at
[1] for an example.

[1]
http://svnweb.freebsd.org/base/user/bryanv/vtnetmq/sys/dev/virtio/network/if_vtnet.c?revision=252451&view=markup

-----------------


>
>
>
> -adrian
>



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