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From: David Miller <davem@davemloft.net>
To: dada1@cosmosbay.com
Cc: netdev@vger.kernel.org
Subject: Re: [RFC] net: release dst entry in dev_queue_xmit()
Date: Tue, 24 Mar 2009 23:43:54 -0700 (PDT)	[thread overview]
Message-ID: <20090324.234354.43714160.davem@davemloft.net> (raw)
In-Reply-To: <49C380A6.4000904@cosmosbay.com>

From: Eric Dumazet <dada1@cosmosbay.com>
Date: Fri, 20 Mar 2009 12:40:22 +0100

> I believe we can release dst in dev_queue_xmit(), while cpu cache is
> hot, since caller of dev_queue_xmit() had to hold a reference on dst
> right before. This reduce work to be done by softirq handler, and
> decrease cache misses.
> 

This will break various packet schedulers and classifiers.

Heck sch_sfq.c even uses skb->dst as part of it's flow hash
function :-)

  parent reply	other threads:[~2009-03-25  6:44 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-20 11:40 [RFC] net: release dst entry in dev_queue_xmit() Eric Dumazet
2009-03-20 14:10 ` Neil Horman
2009-03-25  6:43 ` David Miller [this message]
2009-03-25  7:13   ` Eric Dumazet
2009-03-25  7:17     ` David Miller
2009-03-25 18:22       ` Jarek Poplawski
2009-03-25 18:41         ` Eric Dumazet
2009-03-25 19:18           ` Jarek Poplawski
2009-03-25 19:40             ` Eric Dumazet
2009-03-25 19:54               ` Jarek Poplawski
2009-03-25 20:28                 ` Eric Dumazet
2009-03-25 21:12                   ` Jarek Poplawski
2009-03-25 21:20                     ` Patrick McHardy
2009-05-12  8:12 ` [PATCH] net: release dst entry in dev_hard_start_xmit() Eric Dumazet
2009-05-12  8:21   ` Eric Dumazet
2009-05-12 19:26     ` [PATCH, v2] " Eric Dumazet
2009-05-19  5:19       ` David Miller
2009-05-19  5:44         ` Eric Dumazet
2009-05-19 19:44         ` Eric Dumazet
2009-05-19 21:09           ` Jarek Poplawski
2009-05-19 21:21             ` Eric Dumazet
2009-05-19 21:24             ` David Miller
2009-05-12 19:27     ` [PATCH] " Jarek Poplawski
2009-05-12 19:44       ` Eric Dumazet
2009-05-12 20:05         ` Jarek Poplawski
2009-05-12 20:24           ` Jarek Poplawski
2009-05-12 20:52           ` Eric Dumazet
2009-05-12 20:59             ` Jarek Poplawski

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