On Tue, Sep 30, 2014 at 2:46 PM, Jesper Dangaard Brouer
[off-list ref] wrote:

On Tue, 30 Sep 2014 07:55:36 -0700
Eric Dumazet [off-list ref] wrote:

quoted

On Tue, 2014-09-30 at 16:31 +0200, Florian Westphal wrote:

quoted

Eric Dumazet [off-list ref] wrote:

quoted

If you feel not comfortable with "burst", rename it to whatever you
think is best.
But please, do not hard code magic 7 in your code.

I had hoped that this 'magic' value could be removed
completely, only using bql data for bulking decisions.

But it is apparently not the case, since you guys decided to had it set
to 8, then to 7 later, based on experiments.

The "magic" limit is only a conservative save guard.  We do plan to
remove this completely.  That is the reason for not exporting this, as
we want free-hands to remove this completely.

Guess, I'll remove it completely now, so we can move on.


I would like some off/on switch, exported to userspace, for disabling
this bulking (then we don't need this conservative magic number).  How
would that be done best?

I'd suggest to keep the packet limit as an unsigned. Default value is
infinity (-1UL), 0 turns it off, and other values are available if
someone really wants to tune this (for example, if BQL is disabled--
BQL limit is infinity). Export this as sys variable for the TX queue.

Tom

--
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Sr. Network Kernel Developer at Red Hat
  Author of http://www.iptv-analyzer.org
  LinkedIn: http://www.linkedin.com/in/brouer