From: Rusty Russell <rusty@rustcorp•com.au>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: netdev@vger•kernel.org,
virtualization@lists•linux-foundation.org,
Divy Le Ray <divy@chelsio•com>, Roland Dreier <rolandd@cisco•com>,
Pavel Emelianov <xemul@openvz•org>,
Dan Williams <dcbw@redhat•com>,
libertas-dev@lists•infradead.org
Subject: Re: [PATCH 1/4] net: skb_orphan on dev_hard_start_xmit
Date: Thu, 4 Jun 2009 13:24:57 +0930 [thread overview]
Message-ID: <200906041324.59118.rusty@rustcorp.com.au> (raw)
In-Reply-To: <4A26E4FD.5010405@gmail.com>
On Thu, 4 Jun 2009 06:32:53 am Eric Dumazet wrote:
> Rusty Russell a écrit :
> > On Sat, 30 May 2009 12:41:00 am Eric Dumazet wrote:
> >> For TCP, I agree your patch is a huge benefit, since its paced by remote
> >> ACKS and window control
> >
> > I doubt that. There'll be some cache friendliness, but I'm not sure
> > it'll be measurable, let alone "huge".
...
> We can see sock_wfree() being number 2 on the profile, because it touches
> three cache lines per socket and transmited packet in TX completion
> handler.
Interesting, I take it back: got some "after" stats as well?
> Also, taking a reference on socket for each xmit packet in flight is very
> expensive, since it slows down receiver in __udp4_lib_lookup(). Several
> cpus are fighting for sk->refcnt cache line.
Now we have decent dynamic per-cpu, we can finally implement bigrefs. More
obvious for device counts than sockets, but perhaps applicable here as well?
Rusty.
next prev parent reply other threads:[~2009-06-04 3:55 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-29 14:14 [PATCH 1/4] net: skb_orphan on dev_hard_start_xmit Rusty Russell
2009-05-29 15:11 ` Eric Dumazet
2009-06-01 12:27 ` Rusty Russell
2009-06-03 21:02 ` Eric Dumazet
2009-06-04 3:54 ` Rusty Russell [this message]
2009-06-04 4:00 ` David Miller
2009-06-04 4:54 ` Eric Dumazet
2009-06-04 4:56 ` David Miller
2009-06-04 9:18 ` [PATCH] net: No more expensive sock_hold()/sock_put() on each tx Eric Dumazet
2009-06-04 9:26 ` David Miller
2009-06-10 8:17 ` David Miller
2009-06-10 8:30 ` Eric Dumazet
2009-06-11 9:56 ` David Miller
2009-06-01 19:47 ` [PATCH 1/4] net: skb_orphan on dev_hard_start_xmit Patrick Ohly
2009-06-02 7:25 ` David Miller
2009-06-02 14:08 ` Rusty Russell
2009-06-03 0:14 ` David Miller
2009-07-03 7:55 ` Herbert Xu
2009-07-04 3:02 ` David Miller
2009-07-04 3:08 ` Herbert Xu
2009-07-04 3:13 ` David Miller
2009-07-04 7:42 ` Herbert Xu
2009-07-04 9:09 ` Herbert Xu
2009-07-05 3:26 ` Herbert Xu
2009-07-05 3:34 ` Herbert Xu
2009-08-18 1:47 ` David Miller
2009-08-19 3:19 ` Herbert Xu
2009-08-19 3:34 ` David Miller
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