From mboxrd@z Thu Jan  1 00:00:00 1970
From: Robert Olsson <Robert.Olsson@data.slu.se>
Subject: Re: netif_tx_disable and lockless TX
Date: Fri, 2 Jun 2006 12:46:35 +0200
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Cc: Robert Olsson <Robert.Olsson@data.slu.se>, hadi@cyberus.ca,
	Herbert Xu <herbert@gondor.apana.org.au>,
	netdev@vger.kernel.org, jgarzik@pobox.com, mchan@broadcom.com,
	David Miller <davem@davemloft.net>, Andi Kleen <ak@suse.de>
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To: Stephen Hemminger <shemminger@osdl.org>
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Stephen Hemminger writes:

 > I also noticed that you really don't save much by doing TX cleaning at 
 > hardirq, because in hardirq you need to do dev_kfree_irq and that causes 
 > a softirq (for the routing case where users=1). So when routing it 
 > doesn't make much difference, both methods cause the softirq delayed 
 > processing to be invoked. For locally generated packets which are 
 > cloned, the hardirq will drop the ref count, and that is faster than 
 > doing the whole softirq round trip.

 Right. Also the other way around, repeated ->poll can avoid TX hardirq's.

 Cheers.
						--ro