From: "Guo-Fu Tseng" <cooldavid@cooldavid.org>
To: David Miller <davem@davemloft.net>
Cc: chavey@google.com, ethanhsiao@jmicron.com, netdev@vger.kernel.org
Subject: Re: [PATCH v2.6.33 2/2] jme: Adding lock to protect vlgrp structure.
Date: Tue, 16 Mar 2010 15:15:50 +0800 [thread overview]
Message-ID: <20100316071242.M65171@cooldavid.org> (raw)
In-Reply-To: <20100315.155350.26952440.davem@davemloft.net>
On Mon, 15 Mar 2010 15:53:50 -0700 (PDT), David Miller wrote
> From: "Guo-Fu Tseng" <cooldavid@cooldavid.org>
> Date: Tue, 16 Mar 2010 03:13:33 +0800
>
> > The vlan_rx_register is called through ioctl.
> > And the packet feeding is called in the tasklet.
> > I see no lock in register_vlan_dev(), register_vlan_device(), and vlan_ioctl_handler()
> > which is related to the vlan_hwaccel_receive_skb(), vlan_hwaccel_rx().
> >
> > It prevents the vlgrp pointer be modified while trying to feed the packet.
>
> This is not how you fix this. Adding a new lock to your hot code
> path of packet receiving is the last thing you should be doing.
>
> Instead, do what other drivers do, take down the device and bring it
> back up again when changing the ->vlgrp pointer.
>
> See drivers/net/tg3.c:tg3_vlan_rx_register() for an example.
I see. I'll work on it.
--
Guo-Fu Tseng
next prev parent reply other threads:[~2010-03-16 7:16 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-15 5:15 [PATCH v2.6.33 1/2] jme: Fix VLAN memory leak cooldavid
2010-03-15 5:15 ` [PATCH v2.6.33 2/2] jme: Adding lock to protect vlgrp structure cooldavid
2010-03-15 18:22 ` Laurent Chavey
2010-03-15 19:13 ` Guo-Fu Tseng
2010-03-15 22:53 ` David Miller
2010-03-16 7:15 ` Guo-Fu Tseng [this message]
2010-03-16 7:40 ` Eric Dumazet
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