netdev - Re: [PATCH take 2] pkt_sched: Fix qdisc_watchdog() vs. dev

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

Message-ID: <20080914214331.GB2540@ami.dom.local>
Date:	Sun, 14 Sep 2008 23:43:31 +0200
From:	Jarek Poplawski <jarkao2@...il.com>
To:	Alexander Duyck <alexander.duyck@...il.com>
Cc:	Herbert Xu <herbert@...dor.apana.org.au>,
	David Miller <davem@...emloft.net>, netdev@...r.kernel.org,
	kaber@...sh.net
Subject: Re: [PATCH take 2] pkt_sched: Fix qdisc_watchdog() vs.
	dev_deactivate() race

On Sun, Sep 14, 2008 at 03:31:35AM -0700, Alexander Duyck wrote:
...
> What if we were to push the check for netif_tx_queue_stopped further down into
> the qdisc layer so that the basic qdiscs such as pfifo_fast did their own peek
> and in the event that a queue is stopped it just returned NULL and set a flag
> bit?  Basically this would mimic how we are currently handling throttled
> queues (TCQ_F_THROTTLED).  Then in turn each parent could do a check on skb ==
> NULL and set the same flag, or they could act like multiq and just skip over
> that leaf and move onto the next because it is stopped.

IMHO it's a very interesting idea. Probably it could be better
evaluated if we have any stats how much this reason of requeing is a
problem with mq devices.

On the other hand, I wondered about a possibility of rehashing to other
queues in some cases during requeuing, which would be impossible after
such change.

Thanks,
Jarek P.
--
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