netdev - Re: [patch 10/11] net: use numa_node in net

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <46FB44A7.3020506@garzik.org>
Date:	Thu, 27 Sep 2007 01:50:31 -0400
From:	Jeff Garzik <jeff@...zik.org>
To:	David Miller <davem@...emloft.net>
CC:	akpm@...ux-foundation.org, Yinghai.Lu@....COM,
	Andi Kleen <ak@...e.de>, Al Viro <viro@....linux.org.uk>,
	netdev <netdev@...r.kernel.org>
Subject: Re: [patch 10/11] net: use numa_node in net_device->dev instead of
 parent

(warning, adjusted CC's and added netdev mailing list)

David Miller wrote:
> From: akpm@...ux-foundation.org
> Date: Wed, 26 Sep 2007 18:14:42 -0700
> 
>> From: Yinghai Lu <Yinghai.Lu@....COM>
>>
>> Signed-off-by: Yinghai Lu <yinghai.lu@....com>
>> Cc: Christoph Lameter <clameter@....com>
>> Cc: Andy Whitcroft <apw@...dowen.org>
>> Cc: Jeff Garzik <jeff@...zik.org>
>> Cc: Andi Kleen <ak@...e.de>
>> Cc: "David S. Miller" <davem@...emloft.net>
>> Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
> 
> I'm not applying this, I'm still not convinced it is right.
> 
> The device of netdev->dev is a network subsystem pseudo device and
> it's not a real I/O device at all.  It's there for creating the
> class/net/name info under sysfs for the network device.
> 
> So pulling the NUMA node information out of there is completely

Agreed.

> illogical even if you do add some ugly hack to propagate the NUMA
> information from the I/O device parent into the device struct the
> netdev has embedded in it.

I don't think it's an ugly hack at all.  The following is the standard 
way to tell the net device your parent:

#define SET_NETDEV_DEV(net, pdev)       ((net)->dev.parent = (pdev))

so therefore reading the parent is the standard (only?) way to retrieve 
that same information.

Using IETF RFC language:  Every net driver SHOULD have an associated 
struct device via SET_NETDEV_DEV(), even if it's another pseudo-device 
in the case where the net_device is not associated with real hardware.

However, that said, the overall /system/ employed here is a hack, 
because SET_NETDEV_DEV() does not actually adjust any reference counts 
or anything, for the associated net_device or associated struct device.

Al Viro pointed out problems related to this, ISTR, when someone tried 
to convert net drivers over to using the new devres stuff.  That's why I 
haven't been merging the devres net driver conversions -- they 
exacerbate existing object lifetime-related problems.

	Jeff

-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html