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From: David Miller <davem@davemloft.net>
To: hannes@stressinduktion.org
Cc: netdev@vger.kernel.org, therbert@google.com, jhs@mojatatu.com,
	edumazet@google.com, jeffrey.t.kirsher@intel.com,
	rusty@rustcorp.com.au, dborkman@redhat.com, brouer@redhat.com,
	john.r.fastabend@intel.com
Subject: Re: [PATCH 0/2] Get rid of ndo_xmit_flush
Date: Mon, 01 Sep 2014 14:56:46 -0700 (PDT)	[thread overview]
Message-ID: <20140901.145646.174847768842584425.davem@davemloft.net> (raw)
In-Reply-To: <1409601942.21965.23.camel@localhost>

From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Date: Mon, 01 Sep 2014 22:05:42 +0200

> But as soon as we try to make Qdiscs absolutely lockless, we don't have
> any guard that we don't concurrently dequeue skbs from it and suddenly
> one Qdisc dequeue processing entity couldn't notify the driver that the
> end of the batching was reached. I think this could become a problem
> depending on how much of the locking is removed?

I am certain that batching will require taking the device transmit
lock over the ->ndo_start_xmit() invocations, and therefore the
deferral decisions must atomically be made inside of that context.

  reply	other threads:[~2014-09-01 21:56 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-25 23:34 [PATCH 0/2] Get rid of ndo_xmit_flush David Miller
2014-08-26  6:28 ` Jesper Dangaard Brouer
2014-08-26 10:13   ` Jesper Dangaard Brouer
2014-08-26 12:52     ` Jesper Dangaard Brouer
2014-08-26 16:43       ` Alexander Duyck
2014-08-27  7:48         ` Jesper Dangaard Brouer
2014-08-27  8:37           ` Jesper Dangaard Brouer
2014-08-26 14:40     ` Jamal Hadi Salim
2014-09-01  0:37     ` Rusty Russell
2014-08-27 12:19 ` Jesper Dangaard Brouer
2014-08-27 20:43   ` David Miller
2014-08-27 12:31 ` Hannes Frederic Sowa
2014-08-27 13:23   ` Eric Dumazet
2014-08-27 13:56     ` Jesper Dangaard Brouer
2014-08-27 14:09       ` Eric Dumazet
2014-08-27 20:48       ` David Miller
2014-08-27 20:46     ` David Miller
2014-08-27 20:45   ` David Miller
2014-08-28  1:42     ` Hannes Frederic Sowa
2014-08-30  3:22       ` David Miller
2014-08-30 10:23         ` Jesper Dangaard Brouer
2014-09-01 20:05         ` Hannes Frederic Sowa
2014-09-01 21:56           ` David Miller [this message]
2014-09-01 22:31             ` Hannes Frederic Sowa
2014-09-01 22:35               ` David Miller
2014-08-27 18:28 ` Cong Wang
2014-08-27 19:31   ` Tom Herbert
2014-08-27 20:53     ` David Miller
2014-08-27 20:51   ` David Miller

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